My New CB360, heavily modded, from a long time member here

af7777

New Member
I recently picked up an over bored CB360 cafe racer. It was from a member here who was also an active long time member of hondatwins.
I want to start off by saying he did me right on this bike; I got it for a very fair price, and he has put a ton of work and quality parts in it,
He's rebuilt pretty much everything on this bike and has it at 100mph about 16 months ago.
That being said: it has a ton of issues.
The exhausts were cut short and an open muffler tip was welded onto them. Well, he later found out that made it extremely loud and it also caused a lot of back fires (super short with little back pressure.
I fixed that; cut off the mufflers and put long upswept mufflers on with a baffle.
The issue now is the damn thing won't even start.
I added velocity stacks where he just had K&N filters. The stacks are four inches straight back from the carbs and I have uni foam pods for them. Uni is the brand for me.

After fighting a clutch issue I still am not sure I resolved, the bike will no longer start even with a jump starter on the battery.
When it does/did run, the plugs fowl quickly, but while this forum says to up the jet size, the state of the plugs recommend the opposite. He already has larger jets in there, not sure of the exact size but I'm thinking of going back to stock on the jet sizes. I can always play with the air mixture screw next.

My questions at this moment are: why won't it start? Could exhaust and adding stacks and better filters keep it from starting? When I hit the starter, it doesn't sound like it's "grabbing" or trying to turn over, it sounds like something is just spinning really fast and freely. Could this be due to my clutch? Can the clutch keep it from starting? It's in neutral.

CrazyPJ, and a few other vets, you know the guy who sold it to me; he speaks of you guys like you are legends. He's done a lot to this bike and I want to continue to improve it, but honestly I want to throw a match in the gas tank I'm so mad at it right now.

So why won't it start? Clutch related? Spinning noise starter related? Added exhaust related?

edit: the Uni Foam pods aren't on the velocity stacks in this picture, I've just been saving them for tuning. I can slap them on there now if you think it matters.
 

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If it sounds like "something" is turning over fast and that the motor doesn't sound like it's turning ob=ver, suggests a starter or starter clutch issue. Not the main clutch, the starter clutch.

Thos intakes are now really long which might be OK, but do I see a screen on the intake end? That may be partially restricting airflow but for now I would focus on making sure it turns over properly.
 
If it sounds like "something" is turning over fast and that the motor doesn't sound like it's turning ob=ver, suggests a starter or starter clutch issue. Not the main clutch, the starter clutch.

Thos intakes are now really long which might be OK, but do I see a screen on the intake end? That may be partially restricting airflow but for now I would focus on making sure it turns over properly.

You're right, it's the starter clutch. I'll order the rebuild kit and fix that this weekend. While I'm at it I'm going to take the clutch plates off,clean them and soak them in vinegar overnight, then submerge them in oil before putting them back on. He just put new clutch plates in 2 years ago lol.

I'll kick start it until the starter clutch is rebuilt.

As for the filter, I took that totally off. Now I just have air going through a velocity stack.
Finally, the exhausts are supposedly supposed to reach the back axel. A guru here told him this would solve the back fire and a lot of running issues, so I did that.
 
You're right, it's the starter clutch. I'll order the rebuild kit and fix that this weekend. While I'm at it I'm going to take the clutch plates off,clean them and soak them in vinegar overnight, then submerge them in oil before putting them back on. He just put new clutch plates in 2 years ago lol.

I'll kick start it until the starter clutch is rebuilt.

As for the filter, I took that totally off. Now I just have air going through a velocity stack.
Finally, the exhausts are supposedly supposed to reach the back axel. A guru here told him this would solve the back fire and a lot of running issues, so I did that.

I am not sure if this is different, but with the parts I gave to you there is a "starter rebuild kit" not a starter clutch rebuild kit. I am glad you're on here so I can see the progress of fixing anything I didn't know how to do.

Just in case anyone needs to know exactly what was done engine wise, and hasn't seen it in other threads:
.5 over wiseco pistons, kibblewhite valves and springs, pj rebuilt the carbs to run the k&n filters.
 
Good chance fouling plugs and backfiring are timing issues, not carb issues. You can run it without backfiring with nothing but headers, so having a short exhaust is not automatically the issue. PJs carbs, when synced and set right, typically work very well with an open exhaust and K&N filters. Having been part of the thread with the PO and now here, I am not totally convinced the clutch is being adjusted right.
 
Good chance fouling plugs and backfiring are timing issues, not carb issues. You can run it without backfiring with nothing but headers, so having a short exhaust is not automatically the issue. PJs carbs, when synced and set right, typically work very well with an open exhaust and K&N filters. Having been part of the thread with the PO and now here, I am not totally convinced the clutch is being adjusted right.

I've followed the instructions for the clutch to the T.
i didn't think about timing causing the fouled plugs, but the PO knew what he was doing and set the timing.
I wonder why crazyPJ didn't recommend velocity stacks with his pods? Velocity stacks always are recommended.
 
I am not sure if this is different, but with the parts I gave to you there is a "starter rebuild kit" not a starter clutch rebuild kit. I am glad you're on here so I can see the progress of fixing anything I didn't know how to do.

Just in case anyone needs to know exactly what was done engine wise, and hasn't seen it in other threads:
.5 over wiseco pistons, kibblewhite valves and springs, pj rebuilt the carbs to run the k&n filters.
Right, you're starter works great; probably the reason for the toast gel battery.
It's the engagement that's not happening.
It's a cheap rebuild kit but kind of a big deal to do. I'm going to do it after I get it where it'll start (kick start) AND the clutch is working.
 
I've followed the instructions for the clutch to the T.
i didn't think about timing causing the fouled plugs, but the PO knew what he was doing and set the timing.
I wonder why crazyPJ didn't recommend velocity stacks with his pods? Velocity stacks always are recommended.
Velocity stacks are unnecessary. I've built several 360s with his modded carbs and I ran all of them with the same K&N filters.
 
Velocity stacks are unnecessary. I've built several 360s with his modded carbs and I ran all of them with the same K&N filters.
On a CM400T they are absolutely necessary, but you may be right on a CB360. I'm sure you are based on the number of cafe racer builds I see without them.
However: they can't hurt right?
 
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