Really weird 200s problem

[85_ATC_200S]

Hey i've been having some problems with my 85 200s. I just got done replacing the pull starter like, a week ago maybe and it ran fine then. But when i took it back out it was running like crap and bogging down and wouldn't idle anymore. So i tried adjusting the idle and fuel/air screw and it did nothing. So i cleaned the carb and put it back on and tried again. It was running really rough and had some sputtering wet sounding backfires like if it was getting too much fuel. So i put a new plug in it and tried again, but with no luck to get it to idle good. It isn't smoking so it's not burning oil. And it has great compression. But it keeps charring the plugs, getting like a dirty sooty like film on them, it can be cleaned off tho. Well 2 days ago i went to start it and it has good compression but isn't firing. So i turned off the gas and drained the gas out of the carb. Then i turned the gas back on, pumped the thumb throttle twice (this usually works to get it started when it's flooded) and tried to start it and it still wouldn't fire. I pulled the plug out and it isn't any wetter than is should be. And i held on to the spark plug wire and had the neighbor pull it and it has good spart, and there is a good arc on the plug. So me and the nieghbor tried to pullstart it with his car, once again it had great compression, but it still wouldn't fire, and it has awesome compression so the valves aren't stuck open. Can anyone help me? Could you guys tell me some things that could be wrong? I doublechecked the carb and it's all put back together right.

[moparman]

My first idea would be some bad gas. Too much water condensation this time of year and it causes lots of troubles in small engines. Air gap adjustment maybe? I haven't looked at 85-200S that closely yet to see if it's possible but sometimes vibration can loosen an adjustment screw and suddenly your ignition is screwed up.
Good luck

[85_ATC_200S]

Ok, thanks, i'll try draining the tank and sticking some new gas in it, we'll see what premium does. I might try mixing some HEET with it too.

[moparman]

And when you buy the HEET, use only the RED bottle type. It is isopropyl alcohol based. The yellow bottle is a waste of money.
Or go to NAPA and get a bottle of Thermo-Aid. It is the best for sure.
Don't mix either one very strong. No more than 1/2 bottle in a 5 gallon can. put the ISO in first and then the gas, if at all possible.

Also, premium fuel is great for high compression engines (like the 200X) but you will likely lose power if you use it in the 200S. There is more 'power' using the lower octane fuel because it burns faster. The higher octane slows the burn and doesn't help at all unless you have the high compression to take advantage of it.

[Wickedfinger]

...... when you go to shut it off, does it keep running for a little?. When you rev it, does it take a while for it to settle back down to idle?. The symptoms you've listed sound like its actually running lean from an air leak in the intake tract so inspect it carefully and if you do manage to get it started again, I would shoot a little wd-40 or ether around the carb and boot while its running. If it starts to over-rev ..... you've found the leak, if it dosent then look elsewhere. The main reason I say this is because the 192cc Honda motors are known for this problem when they get a little older.


Also, premium fuel is great for high compression engines (like the 200X) but you will likely lose power if you use it in the 200S. There is more 'power' using the lower octane fuel because it burns faster. The higher octane slows the burn and doesn't help at all unless you have the high compression to take advantage of it.

I guess everyone with a 2-stroke should only be running 87 octane then - the manual says run 89 octane or better, the motor was made to run on that rating and the truth is, you can run the risk of actually overheating a motor by running too low of an octane. Aircooled mills are especially vulnerable to this because the heat exchange that comes from the evaporating fuel contributes to nearly 80% of its cooling. 87 octane is too volitile and burns too hot and quickly to properly cool the motor.

[moparman]

I guess everyone with a 2-stroke should only be running 87 octane then - the manual says run 89 octane or better, the motor was made to run on that rating and the truth is, you can run the risk of actually overheating a motor by running too low of an octane. Aircooled mills are especially vulnerable to this because the heat exchange that comes from the evaporating fuel contributes to nearly 80% of its cooling. 87 octane is too volitile and burns too hot and quickly to properly cool the motor.
Good point Wickedfinger. I did forget to take into account the drop in fuel quality and octane over the past 20 years plus the fact these are aircooled.
Thanks for the info.

[85_ATC_200S]

Thats exactly what it was doing when it was running, i'l gonna check that out, thanks alot wicked finger!

[chuck]

I had the similar problem. i leaned out the air fuel and put the needle on the second clip down and it runs perfect now.