What should decent compression be on a 83 YTM200EK ? (still having starting problems)

[eBoyDog]

After messing with this for so long and finally testing and exchanging used coils, I finally believe I fixed it.

The clue was after I swapped a new spark plug in it which helped it start a little better but then I ohmed out the ignition coil which tested bad so I bought a new one. After doing that it fired up on the first try with the electric start AND with using the rope pull starter, it now starts up on a single pull (which is incredible as I'm disabled and I don't have a lot of upper body strength)! !

I'm tickled pink as now that I have my engine woes taken care of I can move along to fixing up the rest of the trike like cleaning, painting and restoring it.

So for all those with hard starting problems and after working over your carb, you may want to look at your ignition coil.

[barnett468]

Im still having a fit with getting my ytm200 to start, warm weather its fine, once it gets running it runns great with no smoking and awesome throttle response. I have taken the carb apart and cleaned it and even replaced the carb with a used one with no better resulrs.

I checked the compression today and I have almost 150, is this good, bad or average?

it doesnt like to restart if I shut it off after riding it and the engine is hot. Weird... won't start cold (50-60 degree garage and wont restart after its warmed up to normal opertioning temps.

I have checked spark with a spark tester and I seem to be getting good spark.

I still think i may have carb problems but cant rule out ignition coil or the cdi module. Fortunately I have eXta ones of those so i'm going to try swapping that out next I guess since it will only cost me time.

Only way I can get it started in my 50 degree garage is placing a small,what I call a "milk house" heater which blows moderately warm air around the engine and I get everything warm (about 80-90 degress, nothing really hot.

I'm cranking it with the electric start with the trottle wide open...


After putting a new sparkplug in it, it started right off so I suspect the coil could very well be the problem so I'm going to order a new one today and go from there.

Thoughts?

Hi eBoyDog;


Below are some things you can do if you want.

How much choke do you give it when the engine is cold and at what is the outdoor temp at those times?

Look at your spark when the engine is cold and warm. If it is the same that is good.

If the spark is blue, your electrical system is fine.

What color is the spark? If it is lazy and yellow, that is bad but possibly not your prob.

When it fails to restart, look at plug after trying to start it. If it is wet, it is likely rich.

You should not need more than around 1/4 throttle to start it.


CARB

Take a 10” long piece of clear plastic tube.

Connect it to the float bowl drain fitting.

Hold the open end next to the carb even with the carb top.

Open petcock and bowl drain screw.

Gas should partially fill the tube.

The level should be 3mm or .120” below the bottom of the carb body at the float bowl.

High is richer, low is leaner. If it is off by more than around 1/8th inch I would correct it by adjusting the float.

When it fails to restart, look at plug after trying to start it. If it is wet, it is likely rich.

You should not need full throttle to start it.


As Muthey implied, it might be too lean. This is what your signs suggest to me.

Look at the tiny numbers on the side of the carb and post them here.

Look in the online manual below to see what stock sizes are and compare to what you have.

See how may the fuel mix screw is turned out from 0 and post it. I think it’s around 1 1/2 turns.

What is your elevation?

Any mods like pipe to bike?

It’s hard to check cdi’s and coils, it seems that half the time they read bad and still work.

New, possibly Chinese coil

http://www.ebay.com/itm/Yamaha-New-p...#ht_3192wt_938

As cold goes, it was just last week it was minus 15 but that was the "artic vortex", normally this time of year the lows average around 20 or so, this silly thing is driving crazy, once it gets started it runs great.

It most likely needs a pilot jet that is 2 sizes larger than stock to start when its -15. Perhaps you sho
uld move to California.



Free online manuals. Might take 5 minutes to load.

http://www.oscarmayer.net/atc/manuals/

[eBoyDog]

Hi eBoyDog;


Below are some things you can do if you want.

How much choke do you give it when the engine is cold and at what is the outdoor temp at those times?

Look at your spark when the engine is cold and warm. If it is the same that is good.

If the spark is blue, your electrical system is fine.

What color is the spark? If it is lazy and yellow, that is bad but possibly not your prob.

When it fails to restart, look at plug after trying to start it. If it is wet, it is likely rich.

You should not need more than around 1/4 throttle to start it.


CARB

Take a 10” long piece of clear plastic tube.

Connect it to the float bowl drain fitting.

Hold the open end next to the carb even with the carb top.

Open petcock and bowl drain screw.

Gas should partially fill the tube.

The level should be 3mm or .120” below the bottom of the carb body at the float bowl.

High is richer, low is leaner. If it is off by more than around 1/8th inch I would correct it by adjusting the float.

When it fails to restart, look at plug after trying to start it. If it is wet, it is likely rich.

You should not need full throttle to start it.


As Muthey implied, it might be too lean. This is what your signs suggest to me.

Look at the tiny numbers on the side of the carb and post them here.

Look in the online manual below to see what stock sizes are and compare to what you have.

See how may the fuel mix screw is turned out from 0 and post it. I think it’s around 1 1/2 turns.

What is your elevation?

Any mods like pipe to bike?

It’s hard to check cdi’s and coils, it seems that half the time they read bad and still work.

New, possibly Chinese coil

http://www.ebay.com/itm/Yamaha-New-p...#ht_3192wt_938




It most likely needs a pilot jet that is 2 sizes larger than stock to start when its -15. Perhaps you sho
uld move to California.



Free online manuals. Might take 5 minutes to load.

http://www.oscarmayer.net/atc/manuals/

Yes, I did try everything suggested but after replacing the old coil, everything is good now. In the garage in 50 degree temps it will start with one pull of the rope start without even using the choke. I have a carb rebuild kit with new jets but given that it's starting and running perfectly I doubt that I'm going to mess with the carb.

The old ignition coil was old, even the outside shell of it looked bad as the plastic was corroded like the plastic fenders on these 3 wheelers get when exposed to too much sunlight over the years. After replacing it I'm 99 percent sure the old ignition coil was the problem.

Thank you for your suggestions, I was just being bringing up this msg thread as I solved the issue with it's hard cold starting. At least I'm confident now about the VM22sh carb as I had it torn apart so many times that knew it inside and out. As a suggestion to others even if you have a what you think is a good spark, mine was not good enough and with the new coil it's 100 times brighter when checking it visibly.

Thanks to everybody who helped me!