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'67 S90...not a twin!

Troy

Troy

Veteran Member
Joined
Feb 6, 2021
Total Posts
699
Total likes
321
Location
Canmore, Alberta, Canada
So, with the Bomber just tied up waiting for a few parts to be painted but otherwise complete (mostly) it was time to find another project. A little brother to the CB450 & CD175 is a black S90. Will make for nice a little row of bikes when all is done.

I know this is a Twins forum but I'm hoping that you guys will tolerate my little single and that some of the old timers might even have some wisdom they would be willing to share along the wa. I haven't had a chance to look too closely yet but the engine isn't stuck and it seems to shift through the gears. The story is that it was sitting in a shed for 50 years or so. The woman selling it was the original owner and her father bought it for her new in '67 to commute to university. It's briefly passed through one other set of hands since then and the guy I got it from claims to have had it running. Seems in pretty good shape, all things considered. Less than 5000 miles on the odometer and it seems pretty likely to be legit.

IMG_3670.jpegIMG_3669.jpeg
 
Takes me back to my teens. One friend had a C200 90, pushrod engine, another had an S90. Talk about chalk and cheese ! The C200 was a reliable old slogger, the S90 was a little screamer by comparison. Completely different exhaust notes, both bikes on standard silencers with removable baffle tubes removed, S90 much louder, real bark to it. Obviously quicker than the C200, but not as quick as a Yam YG1 73cc stroker ...

( Quick being a relative term, 45 - 55 mph max )
 
Very nice. That's the one I've always wanted. Honda's first OHC single. You'll have to check the harness tag, under the tank to see it's actual age. I'll look for a serial number list. They started in '65.
 
Very cool acquisition Troy, it will be a great restored bike.

Richard Pitman said:
Takes me back to my teens. One friend had a C200 90, pushrod engine, another had an S90. Talk about chalk and cheese ! The C200 was a reliable old slogger, the S90 was a little screamer by comparison. Completely different exhaust notes, both bikes on standard silencers with removable baffle tubes removed, S90 much louder, real bark to it. Obviously quicker than the C200, but not as quick as a Yam YG1 73cc stroker ...

( Quick being a relative term, 45 - 55 mph max )
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Richard, I had one of each in my early riding years, the pushrod CT200 first and the OHC S90 as the next bike. More difficult to compare performance between them because of gearing differences as well as the semi-automatic clutch on the CT200, but the S90 was definitely the better bike to commute to school on.
 
I rode a neighbor's 66' S90 after riding my father's OHC 1970' CT90.. This was in 1974'. The CT90 pulled to 55mph and the S90 pulled to 65+mph:both while laying flat over the bars.
I think the S90 had a better stock camshaft than the CT90?
 
ballbearian said:
Very nice. That's the one I've always wanted. Honda's first OHC single. You'll have to check the harness tag, under the tank to see it's actual age. I'll look for a serial number list. They started in '65.
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Start poking around the bike a bit this afternoon. Serial number S90-586964. Tag on the harness says 1966. I'm hesitant to assume that is the year the bike was made but of course that would be the year that the harness was made. Anybody know better?

A fresh litre of oil, some clean gas.. 3rd kick it started!! Popped it into first and very carefully rode it 100 metres down the snow covered street in first gear before it stalled and wouldn't start again. I don't know why and I'm not really concerned at this point. All in all a fun and successful afternoon.

Looking forward to getting into it a little deeper in the coming months.

Thanks all for your interest and encouragement. I was a little unsure about posting it here...after all the forum actually has the word "TWINS" in the name but I figured it also has the words "VINTAGE" & "HONDA" in it.
 
Fun little bikes! Here is my beater ‘69 model. This ran after years of neglect with some coaxing from a drill spinning the motor over. A quick tuneup later and I was able to make some very unofficial runs down a drag strip with it. Faster than you think.
Yours is in great original shape Troy! Much simpler than the Bomber project of yours. Have fun with it, I’ll have fun following your progress.
IMG_0746.jpeg
 
Ah yes, high school memories. Me on a 50cc Cub looking like Magilla Gorilla .... bonus marks if you know the cartoon .... friend on his S90 leaving me in the dust and the other friend on his Yamaha 100 Twin Jet leaving us both in a haze of 2 stroke oil.

The Yamaha ended up seized while the Cub and S90 continued on with other riders after we had graduated to 4 wheels.

It will be a fun ride around Canmore Troy .... enjoy.

January/February Motorcycle Classics has a good article on the 90's.
 
12ozPBR said:
Fun little bikes! Here is my beater ‘69 model. This ran after years of neglect with some coaxing from a drill spinning the motor over. A quick tuneup later and I was able to make some very unofficial runs down a drag strip with it. Faster than you think.
Yours is in great original shape Troy! Much simpler than the Bomber project of yours. Have fun with it, I’ll have fun following your progress.
View attachment 28293
Click to expand...
Great pic of a great bike. That's just what I wanted about 10 years ago (and blue too) but ended up with the C200 pushrod. If I found one like that, I'd have to make room for it.
 
Really cool little bike, had several from 1965 up.
Is that a silver painted cast iron cylinder?
I think they only had alloy cylinder with liner one year,maybe 65 or 66?
My brother had a 1970 with pressed tin swing arm. the brace tube was perfect place for rear sets and reverse shift pattern also fitted clip-on bars
Probably not too many 90mph S90's ever made?
It was a 'bit heavy' on crankshafts though as you had to slip clutch until 15mph due to high gearing.
I fitted the biggest front sprocket and smallest rear I could find although forget sizes (17/28 or 18/30 maybe?)
I forget, it was a long time ago but know I have a 14/62 somewhere from the 'trials' S90
 
crazypj said:
Really cool little bike, had several from 1965 up.
Is that a silver painted cast iron cylinder?
I think they only had alloy cylinder with liner one year,maybe 65 or 66?
My brother had a 1970 with pressed tin swing arm. the brace tube was perfect place for rear sets and reverse shift pattern also fitted clip-on bars
Probably not too many 90mph S90's ever made?
It was a 'bit heavy' on crankshafts though as you had to slip clutch until 15mph due to high gearing.
I fitted the biggest front sprocket and smallest rear I could find although forget sizes (17/28 or 18/30 maybe?)
I forget, it was a long time ago but know I have a 14/62 somewhere from the 'trials' S90
Click to expand...
Did you have it in the U.K. or here in the States;do you know if the S90's had a better camshaft than the CT90 OHC ??
 
bilbikek411 said:
Did you have it in the U.K. or here in the States;do you know if the S90's had a better camshaft than the CT90 OHC ??
Click to expand...

It was in UK, no idea if camshafts were different but suspect first year or two S90's may have had 'better cams.
By 1970 they were slightly slower than early ones but that may have been due to carb, manifold and air box changes?
 
Troy said:
Thanks all for your interest and encouragement. I was a little unsure about posting it here...after all the forum actually has the word "TWINS" in the name but I figured it also has the words "VINTAGE" & "HONDA" in it.
Click to expand...
Because I was a 15 year old learning about everything motorcycle back then, I never once focused on frame or engine numbers while I owned an S90 as my 4th bike ever in '69. Like all my bikes to that point, it was bought used and raggedy and refreshed with my father's paint work, and we put a CL pipe on it. So yes, any vintage Honda is welcome here and we have the Other Hondas section for that purpose.

1965 S-90.jpg
 
BTW Troy, I don't know how much help they'll be but after looking around for 15 minutes or so and finding most recommending the S90 Yahoo group (which closed in 2020 with all the other Yahoo groups), here is a private FB group. Hopefully they're better than the DOHC 450 group.

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crazypj said:
Is that a silver painted cast iron cylinder?
Click to expand...
Yes, it appears to be. Judging from the wear, crankcase covers appear to be painted, likely other aluminum parts too. Haven't looked too closely yet.

ancientdad said:
BTW Troy, I don't know how much help they'll be but after looking around for 15 minutes or so and finding most recommending the S90 Yahoo group (which closed in 2020 with all the other Yahoo groups), here is a private FB group. Hopefully they're better than the DOHC 450 group.
Click to expand...
Thanks Tom, I've put in a request to join and I'll have a look around. As 12oz observed, this will be a much simpler project than the 450. I'm stunned at how readily available and relatively inexpensive parts are!

I can't go far with it, we are in a small town and leaving town requires highway speeds. A 10 minute ride to the grocery store will be about all, so if it has decent compression and I can tune it up ok and it doesn't leak, then I don't think I'll be doing very much mechanical work. Cosmetics and safety stuff mostly.

It has been fun seeing the nostalgia come out here in the guys a little older than I. Everybody I know who is past the age of 70 seems to have owned one or two of them. I was born in 1970 so it's all a little new to me. I don't remember seeing them on the road during my childhood but of course they must have been everywhere.
 
Troy said:
It has been fun seeing the nostalgia come out here in the guys a little older than I. Everybody I know who is past the age of 70 seems to have owned one or two of them. I was born in 1970 so it's all a little new to me. I don't remember seeing them on the road during my childhood but of course they must have been everywhere.
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Well, I'm almost 70 but I can tell you I'm not really surprised you didn't see many of the smaller bikes, particularly the singles, on the road around your growing up time in the '70s. Even for me at my first Honda shop job at age 15 (almost 16) the older C100/110s, the C200s and C90s, the CB/CL72s/77s and all the 160s were pretty much gone (at least from the shop's service department) by the time I got there in '70.
 
Hey Troy I was wondering if you had started working on your S90 project. I just came across this thread and as you can see from my profile image I too own a S90. Very similar backstory on the bike as it was owned by an old boss of mine who rode it when she went to college and it was purchased for her by her dad. Come to present day it had not been running for about 40 years and her husband asked her to either get it running or sell it as he was tired of moving it. I had expressed an interest at one time so she gave it to me provided I gave it a good home. Finished a modest restoration last year and it is my Sunday around the neighborhood ride. I am not an expert by any stretch but if you run into anything I might be able to help with PM me. Looking forward to seeing your progress on the little beast.
 
ancientdad said:
Because I was a 15 year old learning about everything motorcycle back then, I never once focused on frame or engine numbers while I owned an S90 as my 4th bike ever in '69. Like all my bikes to that point, it was bought used and raggedy and refreshed with my father's paint work, and we put a CL pipe on it. So yes, any vintage Honda is welcome here and we have the Other Hondas section for that purpose.

View attachment 28302
Click to expand...
Do you remember riding your S90 on the road,going places for rides?
What steady speed can a stock S90 maintain while sitting upright, 55,60 ? Or is that difficult if it's windy ?
 
Sitting completely upright about 55~60 is top speed but it drops pretty dramatically if you hit a headwind or incline. (in my experience as a
125lb 17 yr old 50 years ago)
It will keep going for miles at 'red line' in third gear though at about 48mph.
My brother up-geared his, had to slip clutch until at least 10 mph in first but it did 70 in third and a little over 90 flat out (with tailwind or down incline)
We fitted clip-on bars and footrest was a bar through swing arm brace tube, gear lever reversed for 'GP shift' pattern
 
crazypj said:
Sitting completely upright about 55~60 is top speed but it drops pretty dramatically if you hit a headwind or incline. (in my experience as a
125lb 17 yr old 50 years ago)
It will keep going for miles at 'red line' in third gear though at about 48mph.
My brother up-geared his, had to slip clutch until at least 10 mph in first but it did 70 in third and a little over 90 flat out (with tailwind or down incline)
We fitted clip-on bars and footrest was a bar through swing arm brace tube, gear lever reversed for 'GP shift' pattern
Click to expand...
Excellent ! (y)
I like to see a rider making the most of the power on a small cc bike :)
 
Mine is happy at about 50 MPH on the flat with no wind and drops fast going up any kind of hill. I have been wondering if it would help any if I put the new points in that I ordered and never used. Been using the old ones that were in it but I did dress them darn it. :unsure:
 
I didn't ride my S90 too much, I was going through a revolving door of smaller bikes during that period in high school, from a CT200 to that S90 to a CA72 to a new SL175 in barely over a year then. I did ride my CT200 to school every day for a few months and being the pushrod version of the 90, and automatic clutch at that, it wasn't as fast as the S90 (maybe had 6 hp). I probably never got over 50 to 55 during those days.
 
RobMan said:
Hey Troy I was wondering if you had started working on your S90 project. I just came across this thread and as you can see from my profile image I too own a S90. Very similar backstory on the bike as it was owned by an old boss of mine who rode it when she went to college and it was purchased for her by her dad. Come to present day it had not been running for about 40 years and her husband asked her to either get it running or sell it as he was tired of moving it. I had expressed an interest at one time so she gave it to me provided I gave it a good home. Finished a modest restoration last year and it is my Sunday around the neighborhood ride. I am not an expert by any stretch but if you run into anything I might be able to help with PM me. Looking forward to seeing your progress on the little beast.
Click to expand...
Hey RobMan (& others)
Nice to see this thread still can generate a conversation.

To answer the question, the bike is completely dismantled in the garage. The engine is apart and waiting for an order to ship from CMSNL. Took the frame and a few other odds and ends off for powder coating and they are sitting in the basement, also waiting on the parts order. I thought I might update the thread some as things started to come together.

I've managed to gather most everything I need for what I'm hoping will be a 8/10 restoration (maybe a 6 or 7 but these are things I honestly care much about). For me the joy is in the time spent working on the bike, researching and learning.

The 55-60 mph range is what I have read as well, making this a horribly impractical bike for my area. Our town is small and to leave you need to be comfortably doing 110 km/h so I really can't go far with it. My son turns 16 in a couple of years so maybe he'll have the coolest bike in the school parking lot or I'll just go to the grocery store occasionally. I imagine I won't be able to use more than 1/2 tank of fuel in a riding season.

RobMan, what is your experience riding your S90 so far?

If anyone is reading this and they happen to know where a guy could find front foot peg bar for one of these, I'd love to hear from you.
 
Thanks for the update and I was glad to see mine is in the speed range everyone is talking about. As for as my riding experience so far it is currently my only bike that is on the road so I did run through about 2 tanks of gas last summer just short jaunts around the neighborhood usually on Sundays which are the quietest days around here. On my first ride on the rode a box truck nearly wiped me out so yes be careful. One thing to check on yours is the gas cap vent. On my first long ride, about 10 miles one way it started dying on the way back home. I would stop on the side of the rode for about 3 or 4 minutes and it would crank and go about a mile, rinse and repeat. Anyway got home and thought at first an electrical heat related problem but for some reason an obscure bit of knowledge percolated back up in my aged brain and I took another look at the gas cap and the vent hole was plugged solid and took me a bit to find and only a minute to clear. What is wrong with your foot peg bar? I see you have one in the picture so but looks OK from the side I can see. Mine was bent on the left side from a spill at one time or the other but I was able to heat up with a propane torch and straighten just by eye. I will certainly keep an eye out for one though. Anyway I had so much fun with my S90 resurrection I find myself with a CB450 project now which makes me question my sanity from time to time. Good luck with it and have fun.
 
RobMan said:
Thanks for the update and I was glad to see mine is in the speed range everyone is talking about. As for as my riding experience so far it is currently my only bike that is on the road so I did run through about 2 tanks of gas last summer just short jaunts around the neighborhood usually on Sundays which are the quietest days around here. On my first ride on the rode a box truck nearly wiped me out so yes be careful. One thing to check on yours is the gas cap vent. On my first long ride, about 10 miles one way it started dying on the way back home. I would stop on the side of the rode for about 3 or 4 minutes and it would crank and go about a mile, rinse and repeat. Anyway got home and thought at first an electrical heat related problem but for some reason an obscure bit of knowledge percolated back up in my aged brain and I took another look at the gas cap and the vent hole was plugged solid and took me a bit to find and only a minute to clear. What is wrong with your foot peg bar? I see you have one in the picture so but looks OK from the side I can see. Mine was bent on the left side from a spill at one time or the other but I was able to heat up with a propane torch and straighten just by eye. I will certainly keep an eye out for one though. Anyway I had so much fun with my S90 resurrection I find myself with a CB450 project now which makes me question my sanity from time to time. Good luck with it and have fun.
Click to expand...
Except for the encounter with the truck it sounds like fun! Exactly what I'll be doing with mine. By default, I've just ordered a new gas cap for mine.

My foot peg bar is bent as they all seem to be. The tubular steel is also split. I can limp along with no worries but if I can find one that is in good condition or can be easily straightened that would be nice at some point. It seems to be about the only part that I can't find a source for. (That and this funky little bulb that would cost me about cdn $60 with shipping on eBay...https://www.cmsnl.com/honda-s90-super-sport-general-export_model16349/bulb-winker_34905201000/)

I haven't been around here much lately so I missed your introduction of your 450 to the group. Went back and looked at your thread...boy does that bring back memories! My 450 was also a hot mess when I dragged it home. Patience is the key.
 
Troy said:
Except for the encounter with the truck it sounds like fun! Exactly what I'll be doing with mine. By default, I've just ordered a new gas cap for mine.

My foot peg bar is bent as they all seem to be. The tubular steel is also split. I can limp along with no worries but if I can find one that is in good condition or can be easily straightened that would be nice at some point. It seems to be about the only part that I can't find a source for. (That and this funky little bulb that would cost me about cdn $60 with shipping on eBay...https://www.cmsnl.com/honda-s90-super-sport-general-export_model16349/bulb-winker_34905201000/)

I haven't been around here much lately so I missed your introduction of your 450 to the group. Went back and looked at your thread...boy does that bring back memories! My 450 was also a hot mess when I dragged it home. Patience is the key.
Click to expand...
Do you know of a welder who can repair your footpeg bar ?
I have done quit a bit of mods to my footpeg bar for my little 81' Honda CB125S including purchasing a used one off Ebay,then adapting a pair of CB350 folding footpegs to it;I also had a welder strengthen my original footpeg bar and it's quite solid.
 
bilbikek411 said:
Do you know of a welder who can repair your footpeg bar ?
I have done quit a bit of mods to my footpeg bar for my little 81' Honda CB125S including purchasing a used one off Ebay,then adapting a pair of CB350 folding footpegs to it;I also had a welder strengthen my original footpeg bar and it's quite solid.
Click to expand...
I do, and I might go that route. I'm shocked that nobody in Thailand, Vietnam, Indonesia has decided to knock off a batch of these as there seem to be none available and lots of people with old bent ones.
 
I looked up the part number for the footpeg bar this morning and I was also surprised at how few are out there, and none that I found were for any variant of the OHC 90 engine (since they bolt to the bottom of the crankcase, I'd assume the CT90 and others should fit or be pretty close)
 
ancientdad said:
I looked up the part number for the footpeg bar this morning and I was also surprised at how few are out there, and none that I found were for any variant of the OHC 90 engine (since they bolt to the bottom of the crankcase, I'd assume the CT90 and others should fit or be pretty close)
Click to expand...
Another reason this forum is so great...tapping into the wealth of knowledge and creative ideas from the veterans. I did a little research and the S90 shares the same crankcase part numbers with the SL90 and CL90, so it would be reasonable to assume that the mounting holes would be the same for the respective footpeg bar. I found a set for the CL90 on eBay that is reasonably priced. The CL90 has hinged footpegs as opposed to the fixed ones on my S90. Clearly the hinged ones make more sense, (as is evidenced by all the bent fixed position ones) its just a matter of if I want to deviated from the original design or not. Something to think about I guess....

As always, thanks to AD!
 
I'd put the CL90 pegs on it in a heartbeat, absolutely makes more sense. When I had that amalgamated Sachs/Ducati/Honda CT200 mongrel when I was 15, it had the older fixed footpeg bar on it and it bit me once. I was climbing a hill near our campsite and got bogged down, got off and pushed beside the bike as I often had to with the smaller weenie-powered engines I had then, and when I got over the top of the hill I jumped on the bike while it was moving. Right foot went forward of the peg, toe got caught on the ground and the footpeg caused me to mildly sprain my ankle.
 
As long as there is room for the header pipe, why not? Otherwise a big vice and a long pipe can bend the originals straight, if that's the problem.
 
ballbearian said:
As long as there is room for the header pipe, why not? Otherwise a big vice and a long pipe can bend the originals straight, if that's the problem.
Click to expand...
I agree. The bend of the CL peg bar must allow it to go over the S90 low exhaust on the right side.
 
It's an interesting idea and I'll explore it further. Looking closely at reference photos of both bikes it "appears" that they "might" be interchangeable but unless you had the bike assembled (which I don't at the moment) and you had the peg bars it's hard to know for certain. For now it will go on the list for another day.
 
It's a fair point, and one reason I didn't think about it at the moment was my S90 had an aftermarket upswept CL-style pipe. I didn't have clearance problems with that arrangement, but with a stock S90 low pipe it may very well lack the clearance.
 
Getting started with the reassembly the last couple of weeks. Made a little whoops by installing new wheel bearings on the front wheel and neglecting to install the spacer inside the hub between the 2 sets of bearings. I'm going to have to pull one bearing to get the spacer in which I assume will render that bearing useless.

My question is...assuming the correct dimensions, are all bearings alike? Living where I do I will need to order one online and have it shipped. There is quite a range of options.
$20/each from CMSNL
$2.50/each from 4into1
$20.00 for 10 from Amazon (Although I certainly don't need 20 of them, this is certainly the easiest option for me.)

www.cmsnl.com

B/BRG RAD N/COM for S90 SUPER SPORT GENERAL EXPORT - order at CMSNL

✓Good to order: B/BRG RAD N/COM ✓Manufacturercode: 96140-63010 ✓Quality part
www.cmsnl.com www.cmsnl.com

4into1.com

Double Sealed Wheel Bearing - 6301 - 12x37x12

Universal double sealed 6301RS wheel bearing. For front and rear wheels on numerous Honda motorcycles. Check the list below.
4into1.com 4into1.com

 
Troy, 6301 bearings are very common. Try your local auto parts supplier, industrial supply etc.

And yes there is a huge difference in bearings and I avoid the cheap no names. You can buy good ones local for the cost of cheap parts with shipping.
 
Thanks Boomer,
Ya, I realize that they are fairly common. Out here in Canmore I'm a bit limited in what is readily available. What makes Amazon attractive is that they will be delivered to my door for free in a day or two! There is a small NAPA dealer so I'll stop by there and see what they can round up for me.
Cheers
Troy
 
The $2 price range bearings are also the cheap Chinese junk regardless of who's selling them. A good quality bearing will be in the $6-$10 range and have the manufacturers Name and bearing identification stamped. SKF, NTN, Timken, , NSK, Toyo, Nachi are all good choices.
 
After taking the summer away from the garage I'm bike at it with the S90. Since I posted last I've had the frame and other odds and ends powder coated, engine casings vapour blasted and painted as appropriate, new tires, brakes and essentially I have a roller.

Now I'm putting the engine back together but I'm having some troubles and hoping that somebody here can spot the problem. I have assembled, dismantled and reassembled the transmission and shift mechanism more times than I can count and still am going crazy.

It doesn't want to shift cleanly through the gears. Typically the drum doesn't rotate far enough for the next shift drum pin to engage with shift arm to make the next subsequent gear change. Admittedly this is new to me but I would think at this point I should expect the gears to shift decisively and cleanly from 1-4?

I am pretty certain that I have assembled everything correctly, the mainshaft and it's gears, the countershaft and it's gears, as well as the shift drum mechanism. I have spent a week staring at this trying to solve it before coming here. Now I'm prepared to slap my forehead with the palm of my hand when somebody points out some obvious mistake. I feel like its a problem in the shift mechanism but ....help please?!

IMG_0178.jpegIMG_0169.jpegIMG_0171.jpegIMG_0177.jpegIMG_0170.jpegIMG_0172.jpegIMG_0175.jpeg
 
Not sure but I remember getting the short pins wrong and thus the star was on the drum wrong, but it was on a 150.
 
Try spraying/applying some light machine oil to the shift drum/forks and splined gears and shafts next time.
 
Thanks for the suggestion. The pins are the same length, the bores in the drum are different depths, therefore there is only one way that the "star" can be aligned but I'm sure hoping that it is something that simple. I'm totally prepared to order an entire set of parts for a new shift mechanism from CMSNL but sure don't want to do that just to find out that's not what's wrong.
 
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