1981 Suzuki ts185 – very high and increasing rpm once throttle is realeased?

Hey guys,

so basically I've been working on this old ts185 and finally got it running with the air filter on, I've so far taken out the carburetor multiple times and cleaned it out multiple times, and it is finally running. The problem is now that when I start it up the revs insanely high and keep on

Hey guys,

so basically I've been working on this old ts185 and finally got it running with the air filter on, I've so far taken out the carburetor multiple times and cleaned it out multiple times, and it is finally running. The problem is now that when I start it up the revs insanely high and keep on increasing until it's just about to explode, so I adjust the idle screw and back it off and muck around for it a bit until it is steady. When I give it some throttle and then let go (it does go back to its original position) the revs stay at the same rate or higher for an extended period of time (5 seconds) before slowly dying down. Also, when riding the bike I put it in 1st, start riding, then when I pull the clutch in the revs increase for no reason at all (without it having any throttle) and i am either forced to put it back into gear or turn it off.

Any ideas of what the problem could be would be greatly appreciated because it's not really fun riding something that sound likes it's gonna explode because the revs increase that much.

Thnx in advance 🙂

Best Answer:

Shaine: Take a can of brake cleaner or carb cleaner with that straw on the end of the nozzle and when the bike is running, spray it all around the boots, hoses and the carb. Listen to the engine and if the RPM's change after spraying around a certain area you have a leak. Most likely from reinstalling the carb you tore part of the boot. Or one of the bolts isn't tight enough. I had this happen on an old snowmobile. We didn't touch the intake manifold but there was a loose bolt where it attached to the engine. It was right under the part where the intake boot attached. After I tightened it the sled ran great!

If that doesn't help, you may have accidentally put part of the carb back together incorrectly. Even a small change like putting the butterfly valve facing a different direction will effect the engine performance.

Other answer:

Shaine:
It has a vacuum leak, or "air leak" caused by the rubber boot between the carb and cylinder….or a crank seal that is bad.

Physically look at the boot and gasket areas. You can usually see cracks if you flex them just a little.

Also, check to be sure your slide is in the right way around, and all the way down.

Then have a friend start the bike while you immediately start spraying water (mist bottle) or oil spray like WD40, or pb blaster at the junction. If it's leaking, there will be a change in rpm, or smoke from the exhaust.
If it's the crank seals, you can temporarily seal them with some grease for testing purposes.

Don't run the engine more than a few seconds if it's going to scream.
Find the air leak and fix it, aluminum melts at 1200 F.

guardrailjim:
From taking the carburetor off so many times, there is now an intake manifold air leak.
Remove the carburetor again.
Spray some contact/brake cleaner into the manifold and wipe it all around the inside of the manifold to get it nice and slippery.
Contact/brake cleaner is available at bike and auto parts stores.
Pop the carburetor back into the manifold.
Tighten the clamp securely to make sure that the carburetor is making an air tight seal.
Candid Chris:
Besides the leaks in the manifold boot, remove the air-box/filter and check on the return action of the carb slider, it should be a quick snap-down. If not the cable may have a kink in it or needs lube or the slider is worn thus gets stuck in the carb barrel.

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