Topic: CL200 Carb Questions - Hesitation on Acceleration

[DaveBarbier]

Anyone know if the needles in the CL200 have a Keihin "K" stamped onto them? I'm dealing with the carbs on this bike and see that the jets are all aftermarket and not even the correct size. Curious if the needles are aftermarket too because they don't have a stamp.

Also, is there info somewhere that says what needle is for the CL200? Google didn't turn up any needle numbers.

I see that the mains are readily available but the slows aren't. Any other jet resources? I tried Jetsrus, partzilla, DSS and a plethora of other parts distributors. CMSNL says they have them but it's over $30 in shipping for two jets.

Thanks

[CycleRanger]

Check this out: http://www.hondatwins.net/forums/12-smaller-twins-125-200-cc-s-ca-cb-cl-ss-1959-1976

[DaveBarbier]

Thanks CycleRanger, I actually just signed up and posed the question. Nice guys over there.

[CycleRanger]

I'm pretty thick...    
I forgot I actually have the carb specs for a CL200 in my Tiny Honda Spec Book.
Here ya' go. Posted over at Twins too.

[DaveBarbier]

I'm pretty thick...    
I forgot I actually have the carb specs for a CL200 in my Tiny Honda Spec Book.
Here ya' go. Posted over at Twins too.

Cool, I just saved this and commented over at HT.

[DaveBarbier]

I posted this over at the Honda Twins forum. Great guys over there, but just wanted to give my question a little more exposure. Seems to me not to be a specific twins question, but more of an overall carb question.

My CL200 runs and sounds great aside from when the throttle is cracked to about 1/4 throttle...maybe a little less. It's better when it's cold and gets worse as it warms up. There's a blubbering at lower throttle ranges and when I release the throttle to slow down. It also doesn't like choke when it starts up when cold. To me, a layman, it seems like it's rich in the pilot circuit, or IMS circuit.

New battery
New plugs-gapped
New plug caps
Trimmed plug wires 1/4"
New points-gapped
Timing set
Cam chain set
Tappet clearance set
Coil within spec
Carbs cleaned and synced
No air leaks
Stock intake
Repaired stock exhaust (had a lot of holes, I welded them up)

The factory carb settings for the CL200 are as follows:
IMS-1-1/4
Pilot-35
Main-95
Float height-21mm
Needle-middle notch

My settings are almost exactly the same:
IMS-1-1/2
Pilot-38
Main-95
Float height-22.5mm
Needle-middle notch

After a regular 20 minute ride using all throttle ranges and gears I pulled the plugs and see great color.


I did a plug chop for the area in question (just under 1/4 throttle) and see these plugs, also pretty good although the picture shows them more brown than they actually are. Realistically a grayish, but not overly rich at all.


Really trying to get rid of this hesitation and blubbering, and I want to use the choke for a cold start up because it's supposed to. I want to sell this bike but want to give the next owner a great running bike, not something they'll have to bring to a shop to try and fix.

Should I just go ahead and get 35 pilot jets? $41 shipped from CMSNL

Thanks!

[DaveBarbier]

Haha, thanks Cal! I put a PM in to Harrisuluv, doubt he has these jets but thought I'd ask before I spend the $40 on 2 measly crumb sized pieces of brass.

Today I'm going to try checking timing at idle and at full advance and then check again once it's hot. I did this test before but this time I'm going to watch out for any misfiring or weird strobe action when cracking the throttle.

Could be partly a heat/electrical thing. Or even heat/advance spring thing. I'm really reaching, haha.

After this test I'll order the jets. I'm aware the possibility of knocking it out of its tuning equilibrium, doesn't bother me...yet.

[DaveBarbier]

Ok, ignition while hot doesn't seem to be an issue. Spot on at idle and full advance when hot and cold. The transition is nice and smooth.

Going to order those jets. I'll post an update when I try them out for all you people who can't wait to hear the result, haha.

This is almost as exciting as Game of Thrones except a little less nudity.

[DaveBarbier]

Pictures of you nude will NOT be requested. Thanks in advance for your cooperation. 

Fine, but you're missing out!

[grcamna2]

Dave,
You using the original brass carb. parts ?

[DaveBarbier]

Dave,
You using the original brass carb. parts ?

Nope. Unfortunately it looks like I have an aftermarket needle and pilot jet. I just don't see a K stamp on the needle, but not sure if they stamp needles. Both are very hard to find. I have Keihin pilots coming in from CMSNL.

These were rebuilt a few years ago by the PO and he used all aftermarket parts and also the wrong jet sizes. I'm trying to get them back to spec but sourcing parts for these isn't easy. They only made this bike for 1 year.

The part that's throwing me for a loop is that I'm getting great plug color when doing plug chops.

[grcamna2]

oem needles are a pain to find..

[DaveBarbier]

Got my pilot jets from CMSNL. I know they're supposed to be new, and I know they're probably 42 years old but one is pretty dirty and clogged. I'll have to soak them both and clean them out.

Kinda weird

[DaveBarbier]

I opened a ticket with them so we'll see what happens.

They say everything they sell is new but could show signs of wear. No idea if this is actually new and just over 40 years old or if they snuck in a used part, haha.

[DaveBarbier]

Yeah, that's likely what happened. I also didn't get the little CMS figurine guy they normally put into the boxes...pretty upset about that too.

For an hour I was spraying it with carb cleaner and using a brass wire and then a .32mm steel wire from a wire brush. One is clear but the other is super stubborn. I let is sit overnight in carb cleaner. I'm sure it all evaporated by now but hopefully it loosened up.

[DaveBarbier]

Drop it in a tin of MMO and add a little heat. That will help dislodge the stubborn bugger!
(I've used this exact formula to remove people's head from their rectums for years)

Cool, I'll try that.

And yeah, that seems like an interesting procedure for the old "head up the a$$" problem. I'll give that a go too. You learn so much on these forums!

[DaveBarbier]

Not sure why, but the holes in the jets aren't centered. Maybe that's just the quality they had back then. I can see with my own eye that the holes are centered on the screw driver slot end but on the smaller end it's off to the side like it was drilled at an angle, one more than the other. These are stamped with the Keihin 'K'.

[DaveBarbier]

Ugh, why can't everything be perfect all the time?

So I see now that maybe these aren't clogged. The drawing shows what's happening. The hole is angled so if I were to put a .32mm wire in the .35mm hole starting from the right (screw driver slot end) it jams as it exits the left side. I can't put the wire in from the left side because of the drastic angle it has to turn. I can put in a much thinner brass wire because it can turn the corner easier.

Anyone else experience this before?

I'm going to double check it's clear as much as I can then just run with it and see what happens unless others advise against it.

[tbpmusic]

https://jetsrus.com/index.html

[DaveBarbier]

Thanks TBP, but they don't have them. These jets really are not available any place else. Even in aftermarket.

[DaveBarbier]

Issue remains. I didn't do a plug chop but I removed the plugs after the ride and saw that they're a little more rich. As expected I guess. I'm going to put the float height back to exactly stock at 21mm and test.

Not sure what else to do. I'm thinking more that it's not carbs at all...but everything else tests ok.

Could it be my exhaust that I patched up? I'd think it would show up on the plugs if it's running lean or rich, though. Really strange this is.

[DaveBarbier]

My money is on it not being the exhaust.

Same, and I'm glad. I wouldn't want to try and do another exhaust.

[DaveBarbier]

Does this at all sound alike a sync issue? Syncing these carbs is a pain. There's no vacuum ports and you can't bench sync. You need to have the carbs on the bike and put one finger in the throat of one carb while looking into the other as you twist the grip. The goal is to feel and see the the slides moving simultaneously. Not sure if you're familiar with the sync method for the CL/CB200, but it's not easy.

[DaveBarbier]

Actually I'm not certain now that it's a rich idle. At least the plugs didn't show it. I was assuming that because of the larger pilot jet and the symptoms I was feeling.  But yeah, the main jet and actually all throttle ranges minus the small portion I'm having trouble with is great. I'm just trying to confirm my inklings with someone who actually knows what the hell is going on.

[DaveBarbier]

Set the float level to the factory 21mm. Seems to be a little worse. Going to take a break on this bike for a little while. I'm going to fix my lawn mower instead, haha.