250r experts help

[bamatj]

I need some help figuring out what is wrong with my 250r. Here is the specs (the best I know): 1986 ATC250r, bored .030 over, FMF pipe, Boysen reeds i was told, with a small reed spacer (is this reed spacer factory?) 34 mm Keihin flat slide (also is a flatside carb stock?), Uni-filter with airbox lid on, and 185 psi compression. The current jetting i have now is 48 slow jet, 150 main, and a DGH needle. The jets and needle are brand new Keihin. My problem is I am way to rich. Idle to about 3/4 throttle is missing/bogging/sputtering/ just running like crap. When it finally clears up on the upper side it runs fine. But it wont rev hardly at all if you ease into the gas. I have tried different plugs and different gaps and i couldnt tell a differnce except i dont foul as many hot ones. But hopefully I wont run the hot ones anymore when i get it tuned in. I started out with the same size jets that I have now, just a different brand(not sure which brand). I have moved the needle all the way down and it runs slightly better all over except on top end, its a bit slower (probally to lean). But what gets me the most is its flooding so bad that you cannot adjust the idle or the mixture screw. From one extreme to the other it makes no differnce. Well the mixture screw will make it stumble at about 1/4 turn out, but after that its all the same. The idle adjustment can be screwed all the way up or down and it still wont idle. So help me if you can. One person told me the reeds might cause it to flood bad. But im new to 2 strokes so I dont. Is there any hope for this carb or should I just go ahead and punt it? Sorry for the long post.

[Dammit!]

Read the jetting sticky. Twice.

[bamatj]

Ok maybe i was not clear enough. Im new to 2 strokes, but i can turn a wrench. Can somebody tell me why my carb would run so rich that i cant even adjust the idle or the air mixture screw? All the way in and out on the idle adjustment makes no difference. About the same way on the mixture screw. I have tried different slow jets, main jets, needles and needle postions. Hardly any diiference at all where i am having problems.Damnit, I have read plenty on jetting (and not just since ive been having problems). Im thankfull for any help but Im not looking for answers like check your float level. Ive worked on alot of quads but that was all 4 stroke. Im looking for an expert on 2 strokes. So far the only answers Ive got from other people is the slide could be wore out, or the reeds. I have checked the reeds. The are not broke/chipped/or cracked. Someone told me they could not have much if any of gap in them. But they didnt know how much of a gap. Ive got feeler gauges if somebody can tell me how much of a gap they should have. Also again, can anybody tell me if a reed spacer is stock on a 1986 250r. From what i can gather from searching most say they are not. But it sure lools like it is. Im not sure I can get the intake to airbox boot to fit if I remove it. Also can anybody tell me if the factory carb is flat slide? Thanks for any help.

[bamatj]

Ok i went out and took the reeds out. The top part of the reed didnt have a gap between it and the bottom part. The bottom part of the reed had about a .004-.005 gap between it and the cage. Does this sound ok? Somebody told me i could turn the reeds over and this might help it. But now im confused if they meant the actual cage (I dont see how this could make a difference) or the reed pedals. The reed pedals are 2 pieces that look like they are laminated togther. They might come apart with an exacto knife but i dont want to mess them up. Or they might not be made together, its kinda hard to tell. So i cant flip them unless I get them apart. Anybody know if they come apart? Waiting to put it back together.

[oldsking86]

You should just need to unsrew the petals off, and flip them alone. If there is a gap without you moving them then that's your problem. They should be shut, or the slightest bit open. Essense is for them to vibrate sothen need a VERY VERY little gap. Take the spacer off you have on there and just put the cage back on.

[InPiEcEs]

If you look at your reed cage, you will see that the reeds are fastened with screws.
You can remove the screws, and turn the reeds over, so the topside is now down facing the cage.
If I were you, I would check float level. If the float is too high, it may run rich, but the level wont be high enough to run out the overflow tube. The 86 had a 34mm Keihin PJ, which is a flatslide carb. The reed spacer is not stock. Stock would be the intake boot, then the reed cage.
As far as your plug gap, I would go no more than .020"

[Dammit!]

Stock pilot is a 42. There's no reason for you to be using a bigger one. I can't remember off the top of my head how many turns out the pilot screw should be but whatever the factory recommends is just a starting point anyway. Start with it about 2 turns out. One method of dealing with the pilot screw is to turn it in until it starts to die when idling, then turn it out until it starts to die, then set it right in between those two points. I personally just adjust for the best throttle response.

You said the needle is all the way down but people have different definitions of that. Is the needle all the way down or is the needle clip all the way down?

Changing jets to as different brand but the same size is pointless.

My recommendation would be to set the needle clip, pilot jet and air screw back to factory spec and then get the main jet dialed in first. Then get the needle clip dialed in, then adjust the air screw for best throttle response. Doing it in any order other than that is just going to make things harder on yourself.

Edit: stock pilot for '86 was a 42. My bad. Factory setting for the air screw is two and a quarter turns out.

[bamatj]

Ok thanks for the replys. Each reed pedal is 2 peices, I can not simply turn them upside down unless i pry them apart. Im not sure they are suppose to come apart. I will try that if they can come apart. Ok on the pilot I started with a 42 no name. I was told that to use only Keihin jets as the other sizes might not be the same as Keihin. I can turn the mixture screw all the way out and it makes no differnece. I would think with a 42 pilot, no air box lid, and the mixture screw turned all the way out. it should atleast be getting close to lean. But its still loading up bad. I cant keep a spark plug in it. I dont think this is a jetting issuse. Because no matter what i do it doesnt make any noticeable difference from the bottom to 3/4 throttle. I cant keep it running or spark plugs in it long enough to get it jetted. Also on the idle adjustment, its running so rich i cant even tell a difference between all the way up or all the way down. The DGH needle is leaner than the CEJ. The clip is all the way up and the needle is the deepest it can go. Still to rich. The slide has some small parts of chrome wore off it. Would the slide cause this much headache? Its a number 60 slide, is this factory? I can get the main get dialed in fine, thats no big deal. A little under 3/4 throttle on up is easy to adjust and Ive had it running great several times. Ok so is the pedals suppose to have a slight gap or none. .005 gap is pretty small.

[Billy Golightly]

What is the spark plug gap and are you losing transmission oil after its ran?

[Dammit!]

I've only run into one 250R that didn't want to run right no matter what we did. Jetting changes got mixed results, tried known good electrical components, different plugs, just nothing worked. It would run ok one minute, shut it off for a few and then it ran like crap again. At the end of the day we decided it had to be a bad crank seal so it went on the trailer. Not sure what the status of that one is right now. It wasn't one of my machines.

[bamatj]

I am around 30 to 35 thou on the spark plug gap. I changed the oil the other day. I went and checked it and it seems to have lost some.

[oldsking86]

Not to highjack his thread, but what would losing oil have to do with it running lke crap? Bad seals inside the block?

[Dammit!]

Not to highjack his thread, but what would losing oil have to do with it running lke crap? Bad seals inside the block?

If you have a bad RIGHT crank seal it will suck tranny oil into the combustion chamber. A bad LEFT seal will cause it to suck air and go lean.

[ceaserthethird]

just buy a new carb 38 , new set of Reed's .... V-force 3

Should be good to go ...

[Mosh]

I agree,IS the pipe blowing out blue stinky smoke???If so the crank seal has let loose and it will kill your plugs.Another common thing that I seen no-one mention is the coil.They are known to go bad from time to time and the bike will not rev up and it will foul plugs.Any aftermarket killswitches???IF so By pass them.I have seen them go bad and partially short the ignition system.

Your jetting seems to be close enough for it to run decent,So I suspect crank seal,Ign coil or a Kill switch.