Fouling out plugs

[drummerben]

Ok, here's my new issue....
 
I seem to be fouling out plugs left and right. I think (at least from my research) that I am probably too rich on gas. When adjusting the air/fuel screw, does closing it enrichen the gas or make it leaner? Basically I don't get any further than about 10 miles before I notice a difference in performance. When I take off and look at the plug, it has already turned black.

Any help would be awesome.

Thanks.

[Myth]

This link may be of use to you Ben,

http://www.motorcyclephilippines.com/fo ... 28135.html

It discusses A/F ratios.  It also gives one technique for adjusting.  I just stumbled across it, so you might read most or all their info before hand.

Hopefully this helps.

[drummerben]

Well, I found out my problem here. Its not great news, unfortunately. Looks like my piston rings are bad and the engine is sending oil back through the carb,  which in turn is fouling out my plugs. Not sure how all that works, but that is how it was explained to me.
Anyway, I called Scooter Dynasty and they are going to repair my engine, but I have to ship it to them. I'm going to have a buddy of mine help me take it out. Turn around time once they get it will be about four or five days, depending on how busy they are. I'll let you know how this goes. Looks like it could be another few weeks without my bike though. Bummer.

[drummerben]

Well, I may be onto a different solution. I discovered two things:

1. I shouldn't be anywhere near working on small engines.
2. Looks like I overfilled the oil reservoir.

I was researching my symptoms and came across this answer. I decided to drain the oil and do a change...about 2 1/2 to 3 quarts drained out--WAAAAAY too much. I filled with the appropriate amount. The bike is running much better and smoother it seems. I am, however, still experiencing some bogging (same symptoms), but I wonder if the carb still has some oil in it from this problem and is burning it off. I don't know. Any ideas. Hopefully time will tell. I'll let you know how it goes over the next couple of days.

[drummerben]

So I think that changing the oil and filling it to the proper amount has solved my problem. The bike has been riding much better, although I think that I need to tune the carb. I have a friend that will do it for me and he said that he wants to put a bigger jet in it as well as putting an iridium plug in. He believes that the overall speed will also increase (we'll see).

I'll let you know once I get it back and get some miles on it.

[choylifutsoccer]

If you do happen to change the jet in your carburetor, please let me know! I'm wondering which jets fit in the 250GS's carburetor.

[grumpy]

Well, I may be onto a different solution. I discovered two things:

1. I shouldn't be anywhere near working on small engines.
2. Looks like I overfilled the oil reservoir.

I was researching my symptoms and came across this answer. I decided to drain the oil and do a change...about 2 1/2 to 3 quarts drained out--WAAAAAY too much. I filled with the appropriate amount. The bike is running much better and smoother it seems. I am, however, still experiencing some bogging (same symptoms), but I wonder if the carb still has some oil in it from this problem and is burning it off. I don't know. Any ideas. Hopefully time will tell. I'll let you know how it goes over the next couple of days.

Yeh- with that much oil no wonder youre having all those problems!! The engine only takes about 1 qrt, so you only had 3 times more than the amount of oil that you are meant to!  Youre lucky it even started at all!!

Reading through the forum topics re engine poor performance, a lot of issues point to overfilled engine oil.

Probably a good place to start checking when looking for problems is how much oil there is in the sump. I start off by putting about 0.9 qrt in and go up cautiously from there. Often I find that is the exact right amount.