1984 200m starts up and idles at almost WOT

[WheelerBoi]

Hello, I recently bought a 84 200m. When I start the bike it idles at almost WOT.
I cleaned and adjusted the carb. I put the air box back on and it idles abit lower but still very high.
Would this happen because I don’t have an air box cover?
Please help.

[yaegerb]

Hello, I recently bought a 84 200m. When I start the bike it idles at almost WOT.
I cleaned and adjusted the carb. I put the air box back on and it idles abit lower but still very high.
Would this happen because I don’t have an air box cover?
Please help.

Have you tried turning down the idle?

[WheelerBoi]

Yes, turned the idle screw out and adjusted mixing screw

[DAM shop]

Yes, turned the idle screw out and adjusted mixing screw

are you sure your slide is in correctly? cable hanging up? and yes put a lid on it I would start there.

[Gabriel]

If everything is assembled correctly, you could have a vacuum leak. With no load on an engine, it takes VERY little fuel to run wide open. The pilot jet would provide more than enough fuel if it was getting more air than it should. That's also a very bad thing if you run it long. It would be running extremely lean in such a case.



.........take that with a grain of salt though. I have proven that I don't know a GD thing about a fackin' carburetor. Dammit

[WheelerBoi]

Ya I’m sure the slide is in right. It’s probably getting to much air.
Going to have to try and find a air box cover. Shame I can’t get it running properly right now.

[Gabriel]

The airbox cover, while important, wouldn't cause the problems you describe. For the idle to just take off like that, air is getting PAST the carburetor. O-rings are cheap. I would start by pulling the intake, making sure the mating surfaces are clean and flat, then reassemble with a new o-ring on the intake/head side AND the intake/carb side. It'd be the perfect time to have a good look at that carburetor. It may be in serious need of an enema.

[barnett468]

make sure the slide is closing all the way.

if the slide is closing all the way, you can try spraying water at the intake where the carb connects and see if the engine changes rpm or misses slightly etc.

[yaegerb]

make sure the slide is closing all the way.

if the slide is closing all the way, you can try spraying water at the intake where the carb connects and see if the engine changes rpm or misses slightly etc.

Dunno if I would use water but starting fluid or carb cleaner would be sufficient.

[yaegerb]

Ya I’m sure the slide is in right. It’s probably getting to much air.
Going to have to try and find a air box cover. Shame I can’t get it running properly right now.

While putting an airbox cover on is a sound idea, it is likely that the o ring behind your mixture screw is missing, deteriorated or smashed flat and it doesn’t meter air properly. You need to clean and rebuild.

[barnett468]

Dunno if I would use water but starting fluid or carb cleaner would be sufficient.

Actually, oddly enough, water is perfectly fine and won't hurt a thing, I guarantee it. In fact, many high perf engines with nitrous or a turbo are running water injection, and some turbo guys are using a mix of water with methanol. BMW also has a new production car that uses water injection. I have used water injection myself as well, and a big auto parts chain called Pep Boys even used to sell an extremely simple, but not very effective, water kit back in the 80's. Water injection has been around for many years, and even the 1962 Olds Starfire required water injection and it was stock on the vehicle.

Some older model airplanes also had water injection systems, and the first documented use of water in an airplane engine dates back to 1933 with the Wright brothers whom used in their engine.

Water can also be slowly poured directly into the carb of a running engine to break free any semi loose carbon deposits, and this practice has been done for years.

The only time water can really do any appreciable damage to an engine is when it ingests enough to hydrolock, which can cause it to break pistons, or rods etc.

The main reason I suggested water instead of flammable carb or flammable brake cleaner etc in this particular case is because he stated that his engine was revving near full throttle, and I for one wouldn't want to risk making it rev even higher unloaded by using carb or brake cleaner and have that possibly do some damage to it.

Below is some info about water injection that some might find interesting, and there are also countless threads about it on the internet.

https://www.jstor.org/stable/44548241?seq=1#page_scan_tab_contents

https://www.google.com/search?source=hp&ei=6Dq2XMjRDuSw0PEPg5e-wAg&q=water+injection+for+nitrous&oq=water+injection+for&gs_l=psy-ab.1.5.0l10.16031.21547..26691...0.0..0.217.2313.8 j11j1......0....1..gws-wiz.....0..35i39j0i131.-ULWPPNQpSg

https://www.roadandtrack.com/new-cars/car-technology/a25833896/how-water-injection-increases-horsepower/

https://www.roadandtrack.com/car-culture/a31334/bmw-m4-gts-pcoty/

[Gabriel]

That air box cover you looking for.....wonder if a 200ES would be the same? I got one of them floating around somewhere I think. Wing nuts too ........but where. Hmmmm.

[WheelerBoi]

I’ll take some photos tomorrow.

[atc007]

Your slide is in 180 off,or your cable is holding your slide up. The O rings on these are important. Mixture screw and intake boot. But you have one of the 1st 2 problems causing this

[WheelerBoi]

Here is the photo of the air box, I put a new gasket between front boot and motor.

[Gabriel]

Ok, that looks the same as an ES.

I gotta get into the "pile" tomorrow. I will try to find it and put a tape measure on it just to be sure.

[barnett468]

I put a new gasket between front boot and motor.

Why?

Did you try it yet?