hey first post here and ive read the whole thread and tried just about everything.... ive got a 91 rm 250 that dosen't want to start off the kick and now dosen't want to start off a bump very well... i repacked the silencer, re oiled the air filter its got a new top end on it with a wiesco piston and i did a compression test on it and it made around 200 psi on compression so the only thing i can think of is that the carb is off...i got the bike the later part of last season and it rode pretty good it seemed always hard to start and even when warm and when id turn it off it would take a few kicks to start. now it won't start at all ive tried everything.. i rejetted it to what FMF recomends which is a .360 main jet .55 piolet and 1.5 turns out on the screw and still nothing... it keeps spewing gas/oil mixture out of the exhaust where it connects to the jug (starting with GAS OFF and choke full). i tried to bump it the other day down the hill and it started but wouldn't stop idling very high.... anyone have any ideas what i should do next?
RM250 90 RM 250 Starting issue
- Thread starter drew76924
- Start date
the carb was previously set at a .370 main .55 piolet 4 turns out on the screw and position 4 on the needle clip...... its currently set to position 3 on the needle clip.... the top end blew last season and i did a top end on it but didn't touch the carb... i don't know if the guy i bought it from knew the top end was going so he jetted it rich to get some more life out of it or what i don't know if thats the cause that its too rich maybe?
oh no... not another starting issues thread 
Kyle what have you done?? 
first thing you need to do is verify that your crankseals are good, if those are good, make sure your spark plug is clean, after that make sure you are getting a healthy blue spark from the spark plug. If all of that checks out it will come down to jetting, which we can certainly help yu with
Kyle what have you done?? first thing you need to do is verify that your crankseals are good, if those are good, make sure your spark plug is clean, after that make sure you are getting a healthy blue spark from the spark plug. If all of that checks out it will come down to jetting, which we can certainly help yu with
Right things, wrong order. Fist, GET A NEW PLUG! Make sure you are getting good spark,make sure you have proper compression, and make sure you are getting fuel. If all the above are good, then tear into the crank sealoh no... not another starting issues thread
first thing you need to do is verify that your crankseals are good, if those are good, make sure your spark plug is clean, after that make sure you are getting a healthy blue spark from the spark plug. If all of that checks out it will come down to jetting, which we can certainly help yu with
Sorry guys i tried everything i know and i really dont want to have to take it to the dealer...I just didnt know if it was a jetting issue or something else...the plug is brand new and the carb is clean...
How do you check your crank seal to see if is bad? Im a car guy i did my top end on my bike just never got into the bottom...
How do you check your crank seal to see if is bad? Im a car guy i did my top end on my bike just never got into the bottom...
have you checked the reeds, gappy reeds will cause hard starting and flooding.
OK......... Let me get this straight. Youve recently replaced the top end. You have an FMF head pipe. The bike is hard to start and idles way to high. Plus you have an overly rich condition.
Your bike and my bike are only a year apart. I have a 92. Ive had the bike for about 4 years and the first 2 years it gave me much hell. But..... I learned alot. It doesnt make me an expert but Im fairly confident that I (WE) can help you. Im going to give you a TO DO list. And I need to know some more information.
First thing first. I need to know (and so should you) what is the elevation that you live at and where you ride and what the average winter time temperature is. This will help me help you figure out what you main, and pilot jet size should be. We will mess with your jett needle after we get your carb tuned correctly.
Second. Are you running the correct pre mix ratio? Im pretty sure (nearly positive) that your bike calls for 32:1. Thats 4 oz of pre mix oil, to one gallon of min 91 octaine gasoline. Under NO cercumstance should you ever need to deviate from this mix ratio for this particular bike. As for what type of oil you should be using? Well as long as its for a 2 stoke dirt bike engine you will never go wrong. Dont use chain saw, weed whacker or marine pre mix oils. They do work but Ive not had great success with them. I personally like Klotz synthetic, or Redline. Doesnt mean you have to use it but thats what I use.
Third. What type of spark plug are you using? Your factory service manual should say you require the NGK R4118S-8. They are a great spark plug if your jetting is spot on. But as soon as you get too rich its going to foul out on you and quickly and they arent cheap. They are like $10 plus dollars a piece. Ive found these other 3 plugs to work just fine especially when you jetting isnt just right. They are all NGK plugs and are recommended altenates for the factory plug. The first on is the BR8EIX, second is the B8EG, and last is the BP7ES. I run the BP7ES. Its a little hotter of a plug and I have yet to foul one out. Also having the gap set correctly on your spark plug is super important. My manual calls for .022-.026 of an inch. I typically run my gap at .024.
Oh and if you dont have a manual, GET ONE. You will save yourself alot of aggrivation by getting one. Even if you have to down load and print it. Its worth its weight in gold. And when I say a manual I mean the genuine suzuki, Owners Service Manual for your year make model. Dont get a Clymers, or a Haynes. Those manuals are just ok, but Ive heard they are kinda lacking but can get you by.
OK now as mentioned by some of the other guys there are some other things you need to check.
Pull your carb of and then the reed cage. Inspect your reeds. If they are chipped torn, worn, or not perfectly flat, replace them. There are several types of replacement reeds out there. I prefer Boyesen reeds. But you will never go wrong with OEM reeds, especially if you have an OEM reed cage. If your not sure about the condition of your reeds, just replace them they dont cost that much.
You also mentioned that your idle was super high. Have you tried to adjust you idle adjustment screw? Its on the left hand side of your carb and has a little locking nut on it. Get your bike running and warmed up, break that locking nut loose and back out the screw about 2 full rotations just to see what will happen. If you like it set the locking nut.
So once you get me the info that I asked for like where you live, the elevation that you live at, and the average winter time temp I can look at the chart in my manual and tell you what you should be running as far as jetting, goes. Get the right type of spark plug. Any one of the plugs I mentioned will be suitable, make sure they are gapped to the specks I mentioned. Check your reeds. Make sure they are in good shape. If they look like they are a fiberglass color I would just replace them. If they look like they are made of carbon fiber, you may have an aftermarket reed cage. If you have an aftermarket reed cage I need to know that will help me figure out what you should be running for jetting.
One last thing. I need to know every aftermarket part you have on the engine. Headpipe (FMF)(ProCircuit), silencer (FMF), Reed cage (Boyesen)(V Force). etc. Those aftermarket parts will change you jetting alot from factory settings.
Here is a photo of my old girl
This is what your bike could and should sound like after we help you get her running correctly
Your bike and my bike are only a year apart. I have a 92. Ive had the bike for about 4 years and the first 2 years it gave me much hell. But..... I learned alot. It doesnt make me an expert but Im fairly confident that I (WE) can help you. Im going to give you a TO DO list. And I need to know some more information.
First thing first. I need to know (and so should you) what is the elevation that you live at and where you ride and what the average winter time temperature is. This will help me help you figure out what you main, and pilot jet size should be. We will mess with your jett needle after we get your carb tuned correctly.
Second. Are you running the correct pre mix ratio? Im pretty sure (nearly positive) that your bike calls for 32:1. Thats 4 oz of pre mix oil, to one gallon of min 91 octaine gasoline. Under NO cercumstance should you ever need to deviate from this mix ratio for this particular bike. As for what type of oil you should be using? Well as long as its for a 2 stoke dirt bike engine you will never go wrong. Dont use chain saw, weed whacker or marine pre mix oils. They do work but Ive not had great success with them. I personally like Klotz synthetic, or Redline. Doesnt mean you have to use it but thats what I use.
Third. What type of spark plug are you using? Your factory service manual should say you require the NGK R4118S-8. They are a great spark plug if your jetting is spot on. But as soon as you get too rich its going to foul out on you and quickly and they arent cheap. They are like $10 plus dollars a piece. Ive found these other 3 plugs to work just fine especially when you jetting isnt just right. They are all NGK plugs and are recommended altenates for the factory plug. The first on is the BR8EIX, second is the B8EG, and last is the BP7ES. I run the BP7ES. Its a little hotter of a plug and I have yet to foul one out. Also having the gap set correctly on your spark plug is super important. My manual calls for .022-.026 of an inch. I typically run my gap at .024.
Oh and if you dont have a manual, GET ONE. You will save yourself alot of aggrivation by getting one. Even if you have to down load and print it. Its worth its weight in gold. And when I say a manual I mean the genuine suzuki, Owners Service Manual for your year make model. Dont get a Clymers, or a Haynes. Those manuals are just ok, but Ive heard they are kinda lacking but can get you by.
OK now as mentioned by some of the other guys there are some other things you need to check.
Pull your carb of and then the reed cage. Inspect your reeds. If they are chipped torn, worn, or not perfectly flat, replace them. There are several types of replacement reeds out there. I prefer Boyesen reeds. But you will never go wrong with OEM reeds, especially if you have an OEM reed cage. If your not sure about the condition of your reeds, just replace them they dont cost that much.
You also mentioned that your idle was super high. Have you tried to adjust you idle adjustment screw? Its on the left hand side of your carb and has a little locking nut on it. Get your bike running and warmed up, break that locking nut loose and back out the screw about 2 full rotations just to see what will happen. If you like it set the locking nut.
So once you get me the info that I asked for like where you live, the elevation that you live at, and the average winter time temp I can look at the chart in my manual and tell you what you should be running as far as jetting, goes. Get the right type of spark plug. Any one of the plugs I mentioned will be suitable, make sure they are gapped to the specks I mentioned. Check your reeds. Make sure they are in good shape. If they look like they are a fiberglass color I would just replace them. If they look like they are made of carbon fiber, you may have an aftermarket reed cage. If you have an aftermarket reed cage I need to know that will help me figure out what you should be running for jetting.
One last thing. I need to know every aftermarket part you have on the engine. Headpipe (FMF)(ProCircuit), silencer (FMF), Reed cage (Boyesen)(V Force). etc. Those aftermarket parts will change you jetting alot from factory settings.
Here is a photo of my old girl
This is what your bike could and should sound like after we help you get her running correctly
Who installed your topend? If it was you, I know you said you where a car guy, did you make sure the piston was in the right direction? I could be just something as little that causing your issue 
just something else I thought I would throw in the mix as no one seems to have brought that up yet.
just something else I thought I would throw in the mix as no one seems to have brought that up yet.Who installed your topend? If it was you, I know you said you where a car guy, did you make sure the piston was in the right direction? I could be just something as little that causing your issue
I dont even think it would start if piston was in backwards. The rings would spring out and get hung up on the exhaust port I would think and really cause problems. But it is an issue to be concerned with.
elevation is 610ft and right now its about 45 degrees out... i use a 32:1 mixture of Amsoil dominator oil and i was using an NGK BR8es(not gapped) so i'm going to pick up a bp7es today and gap it... i just went ahead and bought new boysen superstock reeds they should be in today... the bike never use to idle high if anything a little low its just that one time when i went to bump it after i messed with the jets that it was idling really high.
the bike has got an FMF headpipe an fmf turbine core silencer and stock reed cage.
ya i put the top end in, i'm pretty sure i put it in correct and i ran it for 2 months last season after i put it in and it ran fine (was always a lil hard to start and had a little throttle hang when reved at idle) but ran good when it was started.... and now its just being a PITA for some reason.
should i check my crank seal?
the bike has got an FMF headpipe an fmf turbine core silencer and stock reed cage.
ya i put the top end in, i'm pretty sure i put it in correct and i ran it for 2 months last season after i put it in and it ran fine (was always a lil hard to start and had a little throttle hang when reved at idle) but ran good when it was started.... and now its just being a PITA for some reason.
should i check my crank seal?