Tidying up my new to me CB450K5

[spideypop]

Well after another 25 mile run with cleaned plugs and no filter material I'm still getting a lot of carbon buildup, essentially like the pics in post 179. I'll recheck timing and see what it looks like.

I did purchase some thinner filter material (pic below). It's about 1/4" thick, the length is perfect and width is real close. I just had to tuck it in a little bit under the outside flange, which holds it in place. I cut it in half and it did both sides.

 

[RobMan]

Wow, I am surprised it is still running rich, I really thought the thick filter material was causing the problem. I guess trying different main jets and see what happens is a next step. I believe I have a 130 in a 14H carb I have but would need to take it apart to confirm. If so you are welcome to it but would have to come up with another one just for troubleshooting.

 

[stl360+450]

I would try the 130's that came with your aftermarket kit.

• The spark plugs can't be expected to stay clean if the bike never reaches operating temperature (short rides) or is run mostly at low rpm.
• You might double check the spark plug gaps.
• I have read that the iridium plugs tend to be less prone to fouling. If you have non-resistor caps, you could try NGK BR8EIX plugs.

 

[ancientdad]

I would try the 130's that came with your aftermarket kit.

• The spark plugs can't be expected to stay clean if the bike never reaches operating temperature (short rides) or is run mostly at low rpm.
• You might double check the spark plug gaps.
• I have read that the iridium plugs tend to be less prone to fouling. If you have non-resistor caps, you could try NGK BR8EIX plugs.

Your first point is definitely one that gets overlooked. If the engine isn't under load the plugs will never look completely clean as they would after a fully warmed-up run on the road for a bit. Of course, that's the reasoning behind doing plug chops - to get a read of the mixture at specific rpm ranges and not just idle mixture after starting with choke on.

 

[spideypop]

Wow, I am surprised it is still running rich, I really thought the thick filter material was causing the problem. I guess trying different main jets and see what happens is a next step. I believe I have a 130 in a 14H carb I have but would need to take it apart to confirm. If so you are welcome to it but would have to come up with another one just for troubleshooting.

I was surprised too. I have both 130's and 140's in my rebuild kit so I'm set. Thanks

I would try the 130's that came with your aftermarket kit.

• The spark plugs can't be expected to stay clean if the bike never reaches operating temperature (short rides) or is run mostly at low rpm.
• You might double check the spark plug gaps.
• I have read that the iridium plugs tend to be less prone to fouling. If you have non-resistor caps, you could try NGK BR8EIX plugs.

the last couple rides I was mainly running between 4-5k rpm. I would think that 20-25 mile test runs would give it enough time to get up to operating temp.

Will double check plug gap, along with timing, both static and at rpm to make sure the advance is working. I do have new springs on the advance mechanism.

I am running resistor caps with non-resistor W24ES-U plugs, so I think I'm good there. Time to recheck the following:

1. Plug gap
2. Timing
3. Recheck valve settings and timing chain
4. Compression, cold and hot. I do remember cold compression seemed a little low when I checked right after getting the bike.

Anything else in that list I should include before downsizing the main's?

 

[ancientdad]

the last couple rides I was mainly running between 4-5k rpm. I would think that 20-25 mile test runs would give it enough time to get up to operating temp.

Yes, that length of time and distance would be fully warmed up - but, 4000 to 5000 rpm will only leave a plug color based on off-idle and midrange mixture as well as can often look a little rich compared to more spirited riding.

 

[spideypop]

Yes, that length of time and distance would be fully warmed up - but, 4000 to 5000 rpm will only leave a plug color based on off-idle and midrange mixture as well as can often look a little rich compared to more spirited riding.

Hmmm, interesting . I guess I need to take another test run, maybe on the highway

 

[ancientdad]

Hmmm, interesting . I guess I need to take another test run, maybe on the highway

Again, this is why we do plug chops - if the engine fires at any rpm range, for any length of time, other than the target rpm range where your issues are, the plugs will take on a different color or shade of color from the mixture at the last rpm range during which the plugs were firing. So on models with a kill switch, you ride a steady speed where you want to see the plug color, then pull the clutch and kill the engine simultaneously and coast to the side of the road, then pull the plugs to take a look.

 

[EzPete]

The good ‘ol Italian tuneup is a solid move once you know you’ve got everything broken in, oil flow is good and your brakes are solid.

These engines like higher RPM ranges- particularly the DOHC.

 

[GMX]

Been following this thread with similar issues on my CL450 K6.
Any new progress to report?

 

[spideypop]

Been following this thread with similar issues on my CL450 K6.
Any new progress to report?

I'm currently applying counsel from Robman..."If it's running good, just ride and enjoy it". I've re-timed and made sure the carbs are adjusted per the FSM. It's running good, revs to redline without problems and has plenty of power. I haven't rechecked the plugs since my last post.

That's a long winded way of saying nothing more to report at this time

 

[EzPete]

I'm currently applying counsel from Robman..."If it's running good, just ride and enjoy it". I've re-timed and made sure the carbs are adjusted per the FSM. It's running good, revs to redline without problems and has plenty of power. I haven't rechecked the plugs since my last post.

That's a long winded way of saying nothing more to report at this time

There’s a subforum for ride reports…

 

[RobMan]

I'm currently applying counsel from Robman..."If it's running good, just ride and enjoy it". I've re-timed and made sure the carbs are adjusted per the FSM. It's running good, revs to redline without problems and has plenty of power. I haven't rechecked the plugs since my last post.

That's a long winded way of saying nothing more to report at this time

OK let me revise my counsel with the caveat "and check the plugs every now and then and see how they look".