1975 CL360 Rich idle

Hello, I've been working on this bike a little while now, here and there when I have time. It hasn't been driven in over 16 years, and I'm now at the point of driving it around. Anyways, a little about what I've replace. The mufflers were shot, so I replaced them with a set of 16" slash cut mufflers from DimeCity, new points, new wires/boots/plugs, tore out the old air filter elements and replaced with the UNI Foam with a thin coating of oil, new coils....replaced with the generic coils from Z1enterprise, new gaskets and o rings for the carbs, set intake valves to .002 and exhaust to .003. So, I've set the timing, it's spot on...as the bike starts practically on the first crank. But my problem is it's running very rich at idle, I can screw the idle mixture screw all the way to snug, and it really doesn't sputter much. I can back it out a bit and it'll backfire a bit and you can smell it's running rich. I have also synced the carbs....best I could get was about 5in of vac on the right carb and about 6.5 in of vac on the left carb. That seems a bit low to me...any on know why that could be so low? While syncing the carbs, I noticed very small changes could effect the idle drastically, and it might rev to 4-5K. I'm almost the limit of how "loose" I can back the sync screw out.

I also get the bike to run decent for a little while. So, I took it out for a quick drive. It sputters when I give it hard throttle...would that be a float issue? If I roll into the throttle slowly it'll rev without sputtering. I do believe the float on the right carb is out of whack, because it was dripping a little fuel when I was hooking up the vac gauges. Also, while on the drive...the rpms wanted to stay at 3-4k when I got off the throttle when rolling up to a stop sign, or shifting gears.

I believe that's all I can think of for now. Sorry if it's difficult to read...just trying to get all the info out. Thanks for any help. I can also take a video of the bike running if that helps at all.

Forgot to mention, that after it was warmed up and I had it out for a cruise....there was some white(but smelled like gas)smoke coming out of the vent tube on the top of the rocker/valve cover.

My theory may be incorrect....just pulled the spark plugs...they're pretty white. The first two of the single plug are the right side, second pair are the left.
Right cylinder on right, and left....


This is the right cylinder.



Left cylinder.

I only skimmed. I will be back later.

Your plugs are crispy. Major lean condition.

Air leaks are likely.

Your tuning knowledge is a bit lacking. You do however seem receptive so you should be ok.

Dont concern yourself with inches of vaccum.

Compression test?

DohcBikes said:

I only skimmed. I will be back later.

Your plugs are crispy. Major lean condition.

Air leaks are likely.

Your tuning knowledge is a bit lacking. You do however seem receptive so you should be ok.

Dont concern yourself with inches of vaccum.

Compression test?

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Oh yes, my knowledge of carbs is very intermediate at best. I'm used to hooking up a PC and tuning my car by wire. So, I'm getting used to this whole carb thing, and I'm trying to learn as much as I can. I'm planning on a compression test, I should call the local parts so to see if I can borrow one quickly. Based on what I've read, it seems the major cause for air leaks are at the intake manifolds.....I will replace the gaskets on the engine side today. I got a gasket kit, and didn't even think to replace them. Dumby.

Dont be afraid to use a little sealant with the gaskets. This is one rare place where i don't mind seeing sealant used with a gasket.

Do not overtighten the boots or the carbs. Just snug and leak free. Overtightening can cause the intakes or the carbs to warp and not seal, along with a host of other issues like slides sticking due to deformation.

Go ahead and remove and completely disassemble the carbs again. They need cleaned and inspected because you have expressed doubt. If your pilot mix screw isnt shutting it off, then the bike is very likely idling on the main or transfer port, and will certainly have a tendency to rev anytime either slide is lifted.

Post pics of the carbs and ask questions when cleaning and setting them.

There might be some 360 carb experts along soon, my advice will be general without lots of pics. Havent seen crazypj for a few days but he's a 360 deity so you might start praying and see if he appears. Or pm him, whatever.

Well, I took the carbs off the bike.....and behold my infinite wisdom, I forgot to install gaskets for the manifolds to engine. I'm sure that didn't help at all. I also discovered a tear in the diaphragm for the carb that always seemed to run a little worse. So, I installed the new gaskets, and I'm going to try and fix the tear in the diaphragm, just for S&Gs while the new one is on it's way. I also cleaned out the carbs again. I made a little float tool out of a floppy disk, saw one online figured it would help get the floats at the right level.

So, now I'm waiting for the sealant to firm up, and I'll throw the carbs back on and see how it runs.

You will not be able to repair the diaphragm permantly. Also, any repair will affect the running and tuning.

Order 2 of them. They are both shot.

Theres really no sense in running it with a damaged diaphragm. When you get the new ones in you'll have to redo the gaskets.

That said, I kinda wanna see how it runs now as well.

ALSO: Be aware now that you should cease all tuning efforts at this point. You have damage to repair first.

+1

If diaphragms are torn, get new ones.

Good catch on the missing manifold gaskets. I was going to suggest checking for air leaks between the carbs and head.

A thin layer of vaseline around the inside of the manifolds where they fit over the carbs helps, too.

Sounds good guys. I was planning to order a pair of diaphragms....they're 40 years old...so they served their time. So, I was looking at how to remove and re-install. Not quite sure how to do that. Anyone have info on the removal and install?

Thanks for all your help.

If you are replacing the diaphragms with OEM, they come complete with slides and springs as an assembly.
If you are going with the aftermarket diaphragms, like the JBMs, they have a instructions on their site.

http://jbmindustries.com/Keihin_diaphragm.html

Condoms is what i sometimes use to check if diagrams are shot. Pinch a hole, put the slide thru and put it back in. Condoms i tell ya!

Bert Jan said:

Condoms is what i sometimes use to check if diagrams are shot. Pinch a hole, put the slide thru and put it back in. Condoms i tell ya!

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ummm...would those be medium or extra manly?

New or used?

alzcbz said:

If you are replacing the diaphragms with OEM, they come complete with slides and springs as an assembly.
If you are going with the aftermarket diaphragms, like the JBMs, they have a instructions on their site.

http://jbmindustries.com/Keihin_diaphragm.html

Click to expand...

Went ahead ordered a pair through this company. Should be here in a few days. I'll throw it all back together and put a video up next week. Thanks for your help guys.

@condoms guy....right on

Well fellas...I'll be happy to announce the bike is back on the road. I got the diaphragms the other day, threw them on yesterday, and went for a quick ride. All seemed to be running very well. Made a few adjustments, and it ripping around again. I will add, my dad bought this bike for my brother when he was 14, he's now 37, about to turn 38. It was driven for a few years by both my brother and I as a learner bike, then life happened and the bike was stored in my dad's garage for the last 18 years. I finally said, how about I pick that bike up and work on it and get it running. Over the last few years I messed with it while I could. My free time is almost entirely consumed by fishing...so it's hard to find time at times... So, this year I said I need to finish this bike when I'm slow for the year, and got at it.

Anyways, enough with the story. Thank you guys for your help. I read countless articles on these bikes on this forum and another and you're all such a help. I already have 40 miles on the bike, from today going to a friends house for a car show. And for a small cc bike it really moves nicely. Cardboard under the CL was because I had a slight leak on the front fork, I have sense fixed it and just keep it there for now, just in case.

Here are a few shots of the bike along side it's lame seafoam green scooter counterpart. Also was given that from my parents because it didn't run. A few mods later and she really books down the street, and has GPS verified top speed of 44mph.

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very cool, but how do your neighbors like your super quiet exhaust pipes?

barnett468 said:

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very cool, but how do your neighbors like your super quiet exhaust pipes?

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My neighbors are pretty used to my shenanigans. I used to own a blown Pontiac Formula with basically open headers, now I have a C5 with a loud exhaust, messing around with my boat on the water hookup in the spring and fall, music, the list goes on. But I brew beer and I keep them happy with that.

Here's a video of it up and running. Thanks again guys.

https://www.youtube.com/watch?v=QiXT_grqG1M

Black_Z28 said:

Here's a video of it up and running. Thanks again guys.

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sounds xlnt but you might want to put a clutch in it and check your clutch springs for spec because it is totally wasted.

where do you live?
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barnett468 said:

sounds xlnt but you might want to put a clutch in it and check your clutch springs for spec because it is totally wasted.

where do you live?
.

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Oh yeah, that clutch is slipping big time. I only have a few weeks left to drive the thing this year, so no biggie. It's been sitting for like 18 years, so there may have been some junk on the clutch disks. I figured I'd drive it and see if anything changes, or I could just drive it like a normal person and not beat on it, and it should be good for while.

I live in Central MN.

Black_Z28 said:

I could just drive it like a normal person and not beat on it, and it should be good for while.

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Where's the fun in that?

once they start to slip that much, they can go completely away in just a few days of daily driving, so not beating on it might be your best and least fun plan.
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