Mikuni throttle slide sticking

[racerone3]

both of my attexs have mikuni VM carbs, and the throttle slides stick in both of them. the one on my racer isn't too bad and has gotten better with use, but the wild wolf is terrible! it will stick wide open and i have to shut down the engine, pop the top off the carb and push the slide back in. i've cleaned the bore on the carb, and the slide, and tried several kinds of lubricant in the bore. any other ideas?

[LarryW]

Is it the slide or the cable? Maybe you could add a spring or stretch the spring thats in there some? Could it be worn enough to cock it sideways in the bore?

Just my thoughts and ideas.

[racerone3]

Is it the slide or the cable? Maybe you could add a spring or stretch the spring thats in there some? Could it be worn enough to cock it sideways in the bore?

Just my thoughts and ideas.

it is the slide in both cases. with the top off the carb the cable moves nice and free... probably should have mentioned that in the first post.

[6X6]

Brian, George was having a similar issue with the Apache, the pin pressed into the carb body to prevent the slide from spinning was worn down enough that the slide would spin, and then jam. The pin can be punched in more for a quick fix, or to see if that's the issue. I use Mikuni Carbs a lot and haven't run into this issue yet, except when dirt or corrosion was an issue on an old Machine.

[George]

Thanks 6x6. I was going to post the same thing. I've only had this problem that one time. For the most part, they're pretty reliable.

See how the pin looks Race.

[racerone3]

Varnish

ok... i took the carb back off, and it had a lot of thick sticky varnish on the engine side of the slide. tore it down an cleaned it again. went for a test drive and it ran terrible, but the throttle didn't stick anymore. i walked away frustrated, and came back a while later to find the throttle stuck shut. pulled the carb again and found the same varnish i hit the key and i'm getting very little fuel from the pump and what i did get is dark brown (same color as the varnish). i cleaned the tank and replaced the fuel lines, but i'm thinking i didn't get it clean enough. any ideas on how to clean a plastic tank without ruining it? there is also a ton of varnish in the intake, which leads me to believe that there will be a lot in the crankcase. any thoughts on cleaning it out without tearing the engine down? i only plan to run it long enough to get the sprocket tubes loose from the axles, so tearing down the engine isn't high on my priority list.
thanks guys

[George]

Sounds like a question for "The Man."

[lewis]

Who could this mystery man be?

[6X6]

Sounds like a question for "The Man."

OK, I'll answer. (Oh, I'm not "The Man" ? Oh well, here's my 2 cents anyways)
Usually a handfull of Ball bearing balls or small nuts with just a bit of gas will knock the gunk loose.
Now the E-10 Gas is causing havoc on Fiberglass tanks in boats by dissolving the resin, which deposites itself when it hits hot metal, usually on the intake manifold and more critically the valves, either wrecking the engine, or causing the tank to leak. I just wonder if it's affecting the plastic in the same way. I haven't noticed this on mine or herd of it on any other 6-wheelers so I don't think so, but???
As long as the plastic isn't soft (And there's no fiberglass patch on the tank)
It should clean out and you'll be set. Maybe flush the line again too since there'll be junk in it again. Running some fuel through the engine should flush out the gunk, since your not too worried about the motor, right?

[LarryW]

OK, I'll answer. (Oh, I'm not "The Man" ? Oh well, here's my 2 cents anyways)
Usually a handfull of Ball bearing balls or small nuts with just a bit of gas will knock the gunk loose.
Now the E-10 Gas is causing havoc on Fiberglass tanks in boats by dissolving the resin, which deposites itself when it hits hot metal, usually on the intake manifold and more critically the valves, either wrecking the engine, or causing the tank to leak. I just wonder if it's affecting the plastic in the same way. I haven't noticed this on mine or herd of it on any other 6-wheelers so I don't think so, but???
As long as the plastic isn't soft (And there's no fiberglass patch on the tank)
It should clean out and you'll be set. Maybe flush the line again too since there'll be junk in it again. Running some fuel through the engine should flush out the gunk, since your not too worried about the motor, right?

Ive also heard the bb/nuts thing but small chain works to and is easy to fetch out. Just tie a string to it and dont let the end fall in.

Ive heard of diesel in the crankcase of 4 stroke and idle it for few seconds to clean them but not sure what you would do on a 2. Maybe just flush it without running it.

[jerseybigfoot]

I had a similar problem with an older Argo Magnum after putting gas line antifreeze in the fuel tank to remove some water. Ended up with sticky sludge blocking the filter, fuel pump and carb. You may want to put some Hydroseal carb dip in the fuel tank to flush the sludge out. I would not worry about the crankcase sludge as it not going to effect the carb. You may want to put a loop in the hose from the crank case to the fuel pump to collect any sludge that pulses out of the crankcase.

[racerone3]

progress...

pulled the tank out this morning, cleaned it again. blew out all the lines and changed the filter. tore the carb apart and cleaned it again on my break at work, tank back in, full of fuel, and blew air in the tank till good fuel ran out the line. now the engine runs great at low speed, but when i get on it, it sputters pretty bad. i'm thinking the pump is full of the varnish. i'll try to find a new one or tear this one apart tomorrow. the good news is that after a test drive and cooling off, the throttle slide isn't covered in varnish and stuck.

[Don]

...not sure who "the man" is either, but here's my 2c.

I have a can of quarter X 1/2" bolts that work great with about a half can of carb cleaner sprayed into the tank first. If you shake it up, let it sit a while, shake again, repeat, etc. it'll clean it up like new. Once you dump it, it may also help to put some clean carb cleaner in it to rinse out any extra junk in there.

Sorry I couldn't get on sooner- After wrecking the truck Friday night, I went into the ER in the wee hours of Monday morning doubled over with stomach pain- got my appendix out yesterday. This is starting off as quite a vacation!

[racerone3]

Sorry I couldn't get on sooner- After wrecking the truck Friday night, I went into the ER in the wee hours of Monday morning doubled over with stomach pain- got my appendix out yesterday. This is starting off as quite a vacation!

man Don! sorry to hear about that. sounds like a rough week!

i got thefuel system clean, but it still isn't running well. does the timing advance on the jlo single work the same as on a twin? it seems like the timing might be off at high RPMs

[Tango42]

Anyone who's hung around attex land here for more than a day knows who "the man" is I Hope "the man" is feeling better and his vacation is a little better from here on out