CL360 Cafe Carb Stumble

Hey guys first time poster but long time lurker. I got a questions for the 360 crowd. I just picked up a CL360 cafe. The guy I got it from has straight pipes on it ending at the passenger pegs, with un-filtered velocity stacks on it. The carbs are the stock Keihins and as far as I can see from pulling off the float bowl it has #68 and #100 jets. The pilot screws are turned out 1.5-1.75 times from seated. The points gap is within spec, smaller then .015 but bigger then .013 since my feeler gauges didn't have .014, and I checked the advance (not with a timing light but by taking of the covers and turning the engine) and it is right on. The bike starts and runs great, a little cold blooded but after about 2 min it warms up and runs great, revs past redline with a few minor hiccups in the mid range, this I have come to understand is from the pipes and the stacks and the only way to correct it is CrazyPJ and his mods. My questions is when I was riding it today I decided to see how well it performed under aggressive riding (I just got the bike and have only put 3.6 miles on it) and when I would rev it to around 8000 and the do a quick up shift and then whack the throttle open real quick after the shift the bike would stumble and cough for a second then clear up and rev clean. Is this just a symptom of the jetting being off? And how would I fix it?

Also since unfiltered velocity stacks are not my ideal air filtration I plan on replacing them with the Uni foam filters, are these any good? The main reason for going with them vs. K&N is the price. I have looked all through the website and can not find a similar situation with my bike, thanks in advance.

If the stacks are properly designed, they'll be better than the Unis or the pods, but still not quite as good as the stock box or pj's modified carbs.

I suspect the majority of your problems are coming from the short exhaust. I had a buddy running his 360 with just the headers and we ended up having to go to 120 on the secondary main jets.

Great thanks, any ball park figures to start with in the jetting, I am at 2500 foot elevation. Also what would be a good exhaust to use. The pipes as is are really loud and the cops here are sensitive to noise violations. Could I just get two mufflers and cut off the curved end of the pipes I have and clamp on the mufflers? What would be a good muffler to get?

I am new to older street bikes, coming from a primarily dirt background, thanks.

If you don't mind making some changes, you can always switch from the CL headers to the CB style. This gives you a lot more options when it comes to mufflers.

The CL headers tend to command a bit of a price, too, so you may end up with enough cash to cover most of the swap.

If you swap out the headers, you probably won't need to make any jetting changes (given your elevation).

For mufflers, I've been pretty happy with these:
http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-exhaust-parts-dunstall-reverse-cone-motorcycle-muffler-80-84051.html

Looks:


And sound:
http://www.youtube.com/watch?v=FmYW7GBX4y8

sounds rich midrange, where in the rpm band is it doing that? those carbs are really hard to get tuned right in the middle range/cruising, from what I've heard, PJ mod's them to correct it

I like the idea of going to the CB type exhaust might do that.

It is happening around the 6000-8000 rpm range. I know it is a little lean because I am running unrestricted intake and exhaust with stock jets. Just need a direction to go in, thanks.

Ply318ci said:

I like the idea of going to the CB type exhaust might do that.

It is happening around the 6000-8000 rpm range. I know it is a little lean because I am running unrestricted intake and exhaust with stock jets. Just need a direction to go in, thanks.

Click to expand...

The way these carbs work is counter intuitive. I wouldn't chalk it up to a lean condition just yet. Increasing the air flow can often lead to a rich condition in the mid range.

Ok, cool I will just get some jets and play around. I think I am going to get air filters though, don't want to ingest to much dirt and ruin the engine or have to change the oil every 500 miles. Is there going to be a difference between the Uni foam type filters and the K&N. I know in the dirt world, the K&N does give you more air flow but at the cost of ingesting more dirt. My Baja prepped XR650R ran a stock type foam filter due to it's ability to filter out the dirt more. The UNI filters are just so much cheaper and right now funds are tight.

The addition of CB headers may interfere w your rear sets.

I've got 2 sets of headers if you're interested

Thanks for the offer. I am going to have to pass as of right now. Turns out there were other things wrong with the bike that I need to fix before I can add to it. The petcock leaks and the floats were out of adjustment so the engine got filled with gas. I changed the oil and disconnected the petcock from the carbs and plugged off the lines. I have searched and I have a factory manual but I can not find how to measure and correctly set the float height, any help or direction as to were to go would be a big help, thanks.

Sure, its pretty easy to do actually. what you want to do is get a depth caliper or even cut a piece of paper in the shape of a U, making sure the 'legs' are 19 mm exactly. remove your carb bowls (carefully since there will be gas in them) and angle the carbs on a table so that the floats are resting against the spring loaded valve stopper. it would be a good idea at this point to make sure those are not gummed up, just push lightly on the float and release it, if it springs back up then they are good and if not they need to be cleaned. Put the template or depth gauge on the surface where the carb bowls were touching, you want the top surface of the floats to be 19mm away from this surface. The tab in the center of the float's bracket is what you need to CAREFULLY bend up or down to get the desired height, you also need to make sure that each side of the float is the same distance away. if they are not then just hold one end and push or pull gently to coax them back into alignment. push on the floats a few times, and when they spring back up measure again. if they measure 19mm then you're all set to go! good luck

So how would I do that with the carbs on the bike? Would I just push the floats up till the seat and then measure from the bottom of the float to the body of the carb? Or is it something different then that? Thanks.

To do it properly you need to remove the carbs, you want them on a table top with lots of light

Alright, looks like I got a small project this weekend, thanks.

So I got everything tuned up great. I took the bike on a 40+ mile ride to the DMV to get it registered, and the bike ran great, would rev straight to red line clean and crisp, shifted great, stopped great. Then it died, it turns out a couple of wires were shot. The main red ignition wire that connected at the white plastic 6 wire connector had gotten corroded at one end and actual broke at the other, it wasn't actually connected. And there was another red wire that came off of the same white plastic six wire connector that goes to the battery was all corroded as well. So I got some bullet connectors and just by passed the plastic white connecter and connected the wires that way. (Yes I did connect the right wire together). Now the bike won't start and when I kick it over to start it it will occasionally pop out of the intake.

I check the valves the other day and they are good, I did the timing a few weeks ago and it is good, and the carbs are synced and the floats are good. I have the pilot screw turned out 1.5 times on each carb and I just installed the Uni foam pod filters. any suggestions would be great.

That red wire feeds your battery from the charging system. The reason the bike died (and won't start) is because your battery is dead.

Yeah I figured that so I charged it with a 2amp battery charger overnight, now it has charge but still wont start. I forgot to add that the bike was running velocity stacks with no filtration at all up till now.

Have you checked for spark?

Not yet. The weird thing is right after I fixed the broken wires the bike started right up and idled fine. I let it sit a few hours to do other things and went out to ride it and that was it, no start.