Non GS, Generic carb help.

[cal_look_zero]

Well unfortunately the Honda guys are about as useful as a screen door on a submarine. I have a really generic carb question.

I dipped and rebuilt the carb on the CM185. It's a little baby keihin. I made sure and blew out all the passages, the jets, whole 9 yards.

I sealed the airbox and intake tube, everything that everyone says to do for the GS carbs.

I can't get the thing to run on anything but full choke though. I had it dialed in for a very very brief moment and then I lubed the chain and it all went to hell.

I'm at a total loss on where to even begin. I set the fuel and air screws to where they were when I disassembled it, but that's gotten me nowhere. I'm wondering if I need to see if I can adjust the slide needle to richen the mixture(not even sure if it has more than one notch), or if I should just bite the bullet and buy some jets and go from there.

Any help would be greatly appreciated. My g/f is expecting her motorcycle lessons on sunday/monday.

 

[tom203]

Well unfortunately the Honda guys are about as useful as a screen door on a submarine. I have a really generic carb question.

I dipped and rebuilt the carb on the CM185. It's a little baby keihin. I made sure and blew out all the passages, the jets, whole 9 yards.

I sealed the airbox and intake tube, everything that everyone says to do for the GS carbs.

I can't get the thing to run on anything but full choke though. I had it dialed in for a very very brief moment and then I lubed the chain and it all went to hell.

I'm at a total loss on where to even begin. I set the fuel and air screws to where they were when I disassembled it, but that's gotten me nowhere. I'm wondering if I need to see if I can adjust the slide needle to richen the mixture(not even sure if it has more than one notch), or if I should just bite the bullet and buy some jets and go from there.

Any help would be greatly appreciated. My g/f is expecting her motorcycle lessons on sunday/monday.

So this is a constant velocity type Keihin- with a vacuum operated throttle slide?

 

[cal_look_zero]

cable goes in that rubber boot at the top, and through a large spring in the slide for the return. Butterfly choke.

 

[Guest]

If you cleaned and dipped as you say you either have a bad air leak some where or your tank is allowing crap through and plugged up your clean carb, when you say it will only run on choke my guess it has a blocked pilot jet

 

[Steve]

... and then I lubed the chain and it all went to hell.

Simple solution: wipe the excess lube off the chain.

It sounds like it's simply not getting enough fuel. Hjfisk has one possibility, here is another:

I set the fuel and air screws to where they were when I disassembled it, but that's gotten me nowhere.

If you will remember, when we re-assemble the carbs on our GSes, we open up the fuel or mixture screws a bit, then add some air, if necessary. If you have separate fuel and air screws, add another 1/4 turn or so to the fuel screw and 1/2 turn to the air screw.

.

 

[Big Rich]

Cal, which Honda guys are you referring to? Some are definitely better than others......

Most likely something found it's way back into the carb and clogged the jets. Do you have an inline fuel filter (aside from the screen in the petcock)? Older Hondas really need a fully charged battery to operate well.

 

[cal_look_zero]

Sounds feasible. The tank was rusty, and I did have to give it the ol toilet bowl treatment. I'll yank the carb out and clean it again. And throw a cheap inline filter in for good measure.

I won't mention the Honda site; suffice to say I posted my question 5 days ago and got one response.

Really showing my age (lack thereof) here, but when you say to "add" turns to the screws... am I turning them in, or backing them out?

 

[Tom R]

Do they have two slotted adjustment screws or one slotted and one knob? For the actual air screw, Clockwise enriches and CCW leans them out - so in this case maybe turn them in a 1/4 turn or so, 1 to 1/1/2 turns is where my Honda carbs usually end up.

 

[mike-s]

Have to agree, sounds like not enough fuel & either a blocked pilot jet (you did say it worked briefly) i guess it worked long enough to draw crap into the lines and then it conked out. removing jets and giving a poke around the lines with thin fishing line is what i'd consider doing, and then set everything back to stock & wind the screws out a half/full turn as others suggested and see where that takes you.

 

[Steve]

Really showing my age (lack thereof) here, but when you say to "add" turns to the screws... am I turning them in, or backing them out?

Most adjustable screw measurements are based on how many turns out from lightly-seated, so you will be turning them OUT, or anti-clockwise.

Do they have two slotted adjustment screws or one slotted and one knob? For the actual air screw, Clockwise enriches and CCW leans them out - so in this case maybe turn them in a 1/4 turn or so, 1 to 1/1/2 turns is where my Honda carbs usually end up.

One easy way to remember which way to turn screws:
Turning the screw LEFT will increase whatever it is controlling.
If it is a fuel screw, it will richen the mixture. If it is an air screw, it will lean it. In the case of the single adjustment on the CV-type carbs, it is a mixture screw, so it will richen it.

.

 

[tom203]

cable goes in that rubber boot at the top, and through a large spring in the slide for the return. Butterfly choke.

A plain non cv type carb -twist throttle, slide moves up, allowing more fuel as long as main jet passes fuel. Sounds like your main jet or passages got clogged up in your first ride. Rusty tanks are full of little surprises.

 

[cal_look_zero]

Cleaned out the carb again, put a small inline fuel filter in, fires up on the 1st kick.

Now I have a cool problem of the throttle being all over the place when I move the bars. Going to yank it all apart again and secure the crap out of the throttle cable.