hi just bought an lt 250r fun and great quad just seems to me it is tuned poorly running gold series fmf pipes and a keihin carberator no clue how it as been modified or ran here is my question or problem at first ran great when started cold oh ya also in winther , when it got hot it would not stop revving unless had it in gear and was running at idle it would just run too fast like sticking thorottle but chequed linkiage and nothing seems to be out of place for that i was told to wait till it got hot and to adjust it when problematic , did so now pretty much the oposite and dont feel like running right here is how i set up my carb , small sprignless screw 1.5 turns and the big one find rediculous but to keep it from revving have it up to like 5 turns that spring seems useless so i find something els is not right can some one give me a pointer wont drive it too much unless to try things since they are supposed to be sensetive to this sort of things well any help apreciated does not leak or burn coolant think has br8es ngk spark plug on it thanks

 

Sounds like you may have an airleak. Try spraying a little carb. cleaner around the intake boot that connects the carb. to the cylinder. Also spray a little around the base gasket if it revs up then you found you're problem. And yes 2 strokes are very sensitive to a lean condition and can overheat and seize or melt the piston.

 

hey thank you for the help you probably saved my motor looks to me the base gasket under the carb looks to be broken quite a bit and seems to have base oil covering the paint so i figure probably this is the trouble i am pretty good at mechanics but not an expert can you tell me if it is a heck of a job or pretty straight forward meaning ,,guess no timing chains but are there some things i can thro off or can i take it appart to there farelly good thanks again ill wait for post or a message from you till fixed it is parked cause i cant afford to worsen it i do have spare gasket for it and a few other things might have to salvage head gasket but at worst will get new one thank you a lot again

 

2 strokes are pretty simple. I would not reccommend using the same piston and rings if you need to replace the base gasket. Now is a good time to do a topend rebuild to freshen it up. Take the carb. off, the reeds out, take the head off and see if anyting is stamped on the top of the piston it may have the size so it will be easier to see what the next size up is. If not a machine shop can mic. it. When you go to separate the cylinder from the cases make sure you don't mare it up. Do not use a screwdriver to separate it. Tapping it side to side with a rubber mallet should break it loose. I would reccommend getting a manuel if it's new to you. To me the most important part is a proper breakin, that will determine the longevity, and performance of the engine. When you get everything back together torque to spec. do one heat cycle then re-torque or you run the chance of blowing the new base gasket. I have had good results using cometic gaskets, you can get the topend kit that has all the gaskets you need.

 

ya thanks since it is my first quad i will park it and do like you said a top rebuild , and also gonna get my other motor complete rebuild ready its in partsin boxes for the moment and who knows whats missing but so far noticed the cylindre sleeve is crack half way looks sleevable thank god and the main unit looks ok but right noe trying to find myself a book or download it if possible