1982 CM450E Revival

I forgot to include carbs fully seated into the insulators, the insulators almost hit the carb body when in fully.
The original needles will be marked at the top of them as 61A or C, C is best as it's the updated version outlined in the service bulletin for surging.
Bulletins:

1982 CM450A Drivability Performance Improvement
“Under part-throttle at low speeds some CM450 Automatic owners may experience poor drivability. This condition can be improved by installing a vacuum cylinder Spring Collar kit and wider gapped spark plugs specified for 1983 450’s “.
Part number 16020-MC1-305 Spring Collar Kit. This is that white plastic ring on top of the carb body when you remove the piston.
Spark plugs specified are NGK DPR8EA-9 gapped at .032”-.036”

1982 CB/CM 450 Drivability Performance Improvement (all manual transmission models: CB450SC, CB450T, CM450C and CM450E
“ Under part throttle operation, some owners of these motorcycles may experience poor drivability performance. This condition can be improved by fitting replacement jet needles”
First step is to replace the needles #61A with new needles #61C. Second step is to replace the mixture screws.
Part numbers: 16113-MC0-305 Needle Jet #61C and 16016-413-751 Pilot Screw
The needle is a the standard needle for a 1983 CM450 A and the Pilot/mixture screw changes numbers to 16016-KC2-970 and shows available still on 4-23-2013. The screw has been used on 121 different engines from 1980 to 2004.
 
LongDistanceRider said:
I forgot to include carbs fully seated into the insulators, the insulators almost hit the carb body when in fully.
The original needles will be marked at the top of them as 61A or C, C is best as it's the updated version outlined in the service bulletin for surging.
Bulletins:

1982 CM450A Drivability Performance Improvement
“Under part-throttle at low speeds some CM450 Automatic owners may experience poor drivability. This condition can be improved by installing a vacuum cylinder Spring Collar kit and wider gapped spark plugs specified for 1983 450’s “.
Part number 16020-MC1-305 Spring Collar Kit. This is that white plastic ring on top of the carb body when you remove the piston.
Spark plugs specified are NGK DPR8EA-9 gapped at .032”-.036”

1982 CB/CM 450 Drivability Performance Improvement (all manual transmission models: CB450SC, CB450T, CM450C and CM450E
“ Under part throttle operation, some owners of these motorcycles may experience poor drivability performance. This condition can be improved by fitting replacement jet needles”
First step is to replace the needles #61A with new needles #61C. Second step is to replace the mixture screws.
Part numbers: 16113-MC0-305 Needle Jet #61C and 16016-413-751 Pilot Screw
The needle is a the standard needle for a 1983 CM450 A and the Pilot/mixture screw changes numbers to 16016-KC2-970 and shows available still on 4-23-2013. The screw has been used on 121 different engines from 1980 to 2004.
Click to expand...

Great information! Thank you so much. I’ll check the needles tomorrow and order new ones, if necessary. My pilot screws are from a non-Honda rebuild kit, so I know they aren’t right. I’ll order those, too.
 
LongDistranceRider, you are the man! I found some NOS needle jets #61C and installed them this morning. I also scrounged around my carb parts and found a couple of Honda mixture screws. I was using aftermarket. They probably aren't the mixture screws that you talk about in your post, but I figured the Honda part has to be better than an aftermarket part of unknown quality.

After installing the needle jets and mixture screws, I took the bike for a short ride and it did great. It didn't surge at all. It's too early to declare a total victory as I only had time for a very short ride, but it was along the same route where I have had surging before. I hope to put some more miles on it Tuesday as long as the rain is gone.

Thanks so much, Jim! I would have never figured that one out without your help.
 
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Time for another overdue update. In an attempt to fix the surging problem, I replaced the needle jets with Honda #61C needles. I also replaced the mixture screws with Honda mixture screws listed in the service bulletin. Additionally, I installed NGK DPR8EA-9 spark plugs gapped at .035. So far, I've done 3 of the 4 things Honda suggested doing in the service bulletins, but my surging problem persists. I'm reluctant to replace the spring collar kit in the carbs because they are so expensive. I'm tempted to wait until after I do the top end rebuild to fix my low compression before I worry about the surging anymore. Besides, the bike runs great with no surging as long as I keep the RPMs slightly high. The surging only shows itself in 2nd, 3rd, and 4th gears. Cruising along in 5th or 6th is never a problem.

Speaking of the top end rebuild, I need someone to please educate me. I did another compression test today on the left cylinder to see if maybe the rings were initially stuck and that had caused my earlier low reading. Now that I've ridden the bike about 100 miles, I figured they would free if they had been stuck. However, the compression is still low. Here's what I don't understand: after doing the compression test I left the compression gauge attached to the left cylinder. I figured that the reading would drop if there is a leaky valve or rings, but the compression gauge reading hasn't changed at all. I did the test about 10 hours ago. Does this mean that my valves and rings are okay, or does the compression gauge hold its reading even if the compression has leaked out? If the rings and valves are okay, why would my compression be low? I suspect I'm just expecting the compression gauge to work in a way that it's not designed to work.
 
LifesShort said:
Time for another overdue update. In an attempt to fix the surging problem, I replaced the needle jets with Honda #61C needles. I also replaced the mixture screws with Honda mixture screws listed in the service bulletin. Additionally, I installed NGK DPR8EA-9 spark plugs gapped at .035. So far, I've done 3 of the 4 things Honda suggested doing in the service bulletins, but my surging problem persists. I'm reluctant to replace the spring collar kit in the carbs because they are so expensive. I'm tempted to wait until after I do the top end rebuild to fix my low compression before I worry about the surging anymore. Besides, the bike runs great with no surging as long as I keep the RPMs slightly high. The surging only shows itself in 2nd, 3rd, and 4th gears. Cruising along in 5th or 6th is never a problem.

Speaking of the top end rebuild, I need someone to please educate me. I did another compression test today on the left cylinder to see if maybe the rings were initially stuck and that had caused my earlier low reading. Now that I've ridden the bike about 100 miles, I figured they would free if they had been stuck. However, the compression is still low. Here's what I don't understand: after doing the compression test I left the compression gauge attached to the left cylinder. I figured that the reading would drop if there is a leaky valve or rings, but the compression gauge reading hasn't changed at all. I did the test about 10 hours ago. Does this mean that my valves and rings are okay, or does the compression gauge hold its reading even if the compression has leaked out? If the rings and valves are okay, why would my compression be low? I suspect I'm just expecting the compression gauge to work in a way that it's not designed to work.
Click to expand...
Are you still reading 135 on the left cylinder? And if so, put a little oil in the cylinder and retest. If the same, rings are not your problem. Maybe a valve is not seating or has tight adjustment.
 
LifesShort said:
Now that I've ridden the bike about 100 miles, I figured they would free if they had been stuck.
Click to expand...
Not all stuck ring conditions are the same of course, and it could take as long as a few hundred miles or it might not happen at all, just a crapshoot really in my experience.
LifesShort said:
I did the test about 10 hours ago. Does this mean that my valves and rings are okay, or does the compression gauge hold its reading even if the compression has leaked out? If the rings and valves are okay, why would my compression be low? I suspect I'm just expecting the compression gauge to work in a way that it's not designed to work.
Click to expand...
Many if not most compression gauges have a schrader valve to release the pressure in case the next cylinder you test is lower, to avoid false readings.
 
ancientdad said:
Not all stuck ring conditions are the same of course, and it could take as long as a few hundred miles or it might not happen at all, just a crapshoot really in my experience.

Many if not most compression gauges have a schrader valve to release the pressure in case the next cylinder you test is lower, to avoid false readings.
Click to expand...
My gauge has a schrader valve and I have to press a button to release the pressure after the test. This time, I purposely didn’t press the button to release the pressure and I left the gauge in the cylinder. So, if I understand you correctly, the gauge is going to hold the pressure reading until I press the button to release the pressure even if there is a leak, correct?

Sorry for my ignorance on this. I just want to make sure I understand.

Thanks!
 
LifesShort said:
My gauge has a schrader valve and I have to press a button to release the pressure after the test. This time, I purposely didn’t press the button to release the pressure and I left the gauge in the cylinder. So, if I understand you correctly, the gauge is going to hold the pressure reading until I press the button to release the pressure even if there is a leak, correct?

Sorry for my ignorance on this. I just want to make sure I understand.

Thanks!
Click to expand...
Yes 🙂
 
I did a wet compression test in the left cylinder today and the compression reading jumped up almost 20psi. I guess I'll definitely be doing a top end rebuild at some point.

A couple of tasks that I have been putting off are next on the list. The fork seals were leaking, so a fork rebuild is needed. Also, I grabbed the forks and tried to wiggle them and there was a little bit of slop. The slop was enough that you could feel it when riding. Time for new, tapered steering head bearings.

Today, I removed the front wheel, forks, and steering head. I will be rebuilding the forks in the next couple of days. I removed the oil plugs on both forks and neither of them had any oil in them. I've got to track down a 14mm Allen wrench to get them apart. Hopefully, I can find one tomorrow.

I also removed the steering head bearings. It turns out that the slop I was feeling was because the steering head nut was only hand tight! I probably could have tightened it and gotten a few more miles out of the bearings, but I decided to go ahead and replace them since I had everything apart. I removed the old bearings and races, but haven't installed the new ones. They are sitting in the freezer waiting for grease and installation.

I hope tomorrow is a good day!
 
LifesShort said:
I did a wet compression test in the left cylinder today and the compression reading jumped up almost 20psi. I guess I'll definitely be doing a top end rebuild at some point.

A couple of tasks that I have been putting off are next on the list. The fork seals were leaking, so a fork rebuild is needed. Also, I grabbed the forks and tried to wiggle them and there was a little bit of slop. The slop was enough that you could feel it when riding. Time for new, tapered steering head bearings.

Today, I removed the front wheel, forks, and steering head. I will be rebuilding the forks in the next couple of days. I removed the oil plugs on both forks and neither of them had any oil in them. I've got to track down a 14mm Allen wrench to get them apart. Hopefully, I can find one tomorrow.

I also removed the steering head bearings. It turns out that the slop I was feeling was because the steering head nut was only hand tight! I probably could have tightened it and gotten a few more miles out of the bearings, but I decided to go ahead and replace them since I had everything apart. I removed the old bearings and races, but haven't installed the new ones. They are sitting in the freezer waiting for grease and installation.

I hope tomorrow is a good day!
Click to expand...
An only 20psi jump may not mean rings. Depending on how much oil you put in the cylinder, as that alone can occupy cylinder space, increasing compression. Get a FSM from @LongDistanceRider and go through the valve adjustment procedure. Also make sure both plugs are out, and choke open, and wide open throttle. Post the compression numbers here. Would like to save you work if we can.

Larry

Edit, just went back and read that you adjusted the valves already. I have used kerosene in cylinders to free up stuck rings before. MMO is used a lot also, as well as an acetone/transfluid mix. Hate for you to have to open nthe engine for nothing.
 
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ferrisbueller said:
An only 20psi jump may not mean rings. Depending on how much oil you put in the cylinder, as that alone can occupy cylinder space, increasing compression. Get a FSM from @LongDistanceRider and go through the valve adjustment procedure. Also make sure both plugs are out, and choke open, and wide open throttle. Post the compression numbers here. Would like to save you work if we can.

Larry

Edit, just went back and read that you adjusted the valves already. I have used kerosene in cylinders to free up stuck rings before. MMO is used a lot also, as well as an acetone/transfluid mix. Hate for you to have to open nthe engine for nothing.
Click to expand...
Do you pour the kerosene into the cylinders? If so, how long do you let it sit?
 
ferrisbueller said:
Get a FSM from @LongDistanceRider and go through the valve adjustment procedure. Also make sure both plugs are out, and choke open, and wide open throttle. Post the compression numbers here. Would like to save you work if we can.
Click to expand...
I'll be out of touch for a few days so if the FSM is needed contact @ancientdad
 
LifesShort said:
Do you pour the kerosene into the cylinders? If so, how long do you let it sit?
Click to expand...
Yes, but not more than a tablespoon ish amount. And let it sit. You will of course need to change the oil. Most penetrating oils are or contain a distillate like kero. If your rings are stuck and carboned, this will help free them. I have used it successfully, but it has also not helped before too. Just depends on what is going on in there. You have nothing to lose, and if it saves you a teardown...

Good luck
Larry
 
ferrisbueller said:
Yes, but not more than a tablespoon ish amount. And let it sit. You will of course need to change the oil. Most penetrating oils are or contain a distillate like kero. If your rings are stuck and carboned, this will help free them. I have used it successfully, but it has also not helped before too. Just depends on what is going on in there. You have nothing to lose, and if it saves you a teardown...

Good luck
Larry
Click to expand...
Thanks! I'll give it a try. I plan to do an oil change once I finish with the steering head bearings and forks, so this is perfect timing for trying kerosene. The only thing I have put down the cylinders previously is Marvel Mystery Oil. Maybe straight kerosene will give better results.

In looking at the weather, today is our last day of sunshine for a while. Beginning tomorrow, we are forecast for 80%-90% rain all day for the next 5 or so days. So, I'm taking my V-Strom out for a ride today and will complete the work on my forks and steering head bearings on the rainy days.
 
I will never buy another motorcycle where half of it is in boxes! Every time I begin work on a different section of the motorcycle there are missing parts. I am replacing the fork seals. Of course, I have to completely disassemble the forks. Everything was going fine until I realized that one of the forks is missing what Honda calls an "oil locking piece." So now I'm stuck. I guess I could put them back together like whoever worked on these last did, but that's not the way I do things. You can still get this part new, but it would cost almost $40 with shipping. Luckily, I found a used one for $12 with free shipping. So now I have to wait for the part to reassemble everything.

Here's what the oil locking piece looks like, if you are not familiar. It's just a spacer that is located in the bottom of the fork.

https://flic.kr/p/2seA5ch
 
LifesShort said:
I will never buy another motorcycle where half of it is in boxes! Every time I begin work on a different section of the motorcycle there are missing parts. I am replacing the fork seals. Of course, I have to completely disassemble the forks. Everything was going fine until I realized that one of the forks is missing what Honda calls an "oil locking piece." So now I'm stuck. I guess I could put them back together like whoever worked on these last did, but that's not the way I do things. You can still get this part new, but it would cost almost $40 with shipping. Luckily, I found a used one for $12 with free shipping. So now I have to wait for the part to reassemble everything.

Here's what the oil locking piece looks like, if you are not familiar. It's just a spacer that is located in the bottom of the fork.

https://flic.kr/p/2seA5ch
Click to expand...
Sure beats thinking you’re missing one, buying a replacement and then realizing the old one was just stuck inside the fork tube.

Anyway. I’ve got an extra one.
 
EzPete said:
Sure beats thinking you’re missing one, buying a replacement and then realizing the old one was just stuck inside the fork tube.

Anyway. I’ve got an extra one.
Click to expand...

Yeah, that was my fear. I checked both fork tubes multiple times just to be sure.
 
I received the oil locking piece yesterday and got it installed. I was then able to complete reassembly of the front end. I now have new fork seals and steering head bearings. If you look closely, you'll notice that the bike has new fork ears. The original fork ears were rusty and bent. They also had small breaks in the metal near the turn signal/headlight mounts. After searching for a decent pair at a decent price on eBay for several months, I decided to order a set of aftermarket fork ears. They are made of brushed aluminum and look very nice in my opinion.

I took the bike out for a 20 mile ride this morning. It's amazing the difference having properly working front suspension makes. It rides so much better, now.

Next on the list is the fix the oil leak at the filter that I created when I changed the oil. I don't know if I made the rookie mistake of forgetting to remove the old gasket or if it's just the cheap aftermarket gasket that is leaking. Before I do this, though, I need to put a little kerosene down the cylinders as ferrisbueller suggested and see if it will free up the rings (assuming stuck rings are the cause of my low compression).


CM450-forks-resized.jpg
 
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