As the title suggests i have a 1985 Suzuki lt250r. I have it running with a compresion of 150 and spark, and the carb seems to work, but maybe not. My problem is that at low rpm's it is very "poppy" and "boggy." Once it gets to higher rpm's it has it's nice power back and throttle response, Any ideas? Im still learning hear so thanks for input.

 

Are you familiar with 2 strokes in general? Poppy is kind of how they are at low rpms and boggy could be a few things. From a clogged idle jet to your premix to a fouled plug, cracked reeds or it might be running like it should without being there it's hard to tell. Also different expansion chambers will make it run different. The 2 strokes basically need to be revving all the time that's how it's designed it's not meant to be lugged or moped around like a four stroke. Fyi anything under 150 psi could use a rebuild which is real easy on a 2 stroke. Are you using fresh premix and a new spark plug?

 

Hasn't been rebuilt yet, so 150 i thought was pretty good. Rebuilds do cost a buck so i wanted to avoid that. I had the cab professionally cleaned and than it quit running so i di a mediocre cleaning that made it work again, it seemed clean though. if it is the needed maybe, how do you clean that. Could it be bad spring that surrounds it? The premix is 32:1. It is supposed to be 20:1 but modern synthetic oil should mean i had to use less. By the way full throttle takes about 3 seconds to kick in. Thank you. Also it will not start even after a long run without chock on.

 

Yeah you can hold out on a rebuild for now. About premix I used to run 32:1 but after my last rebuild I dropped to 20:1 took some time to tune the carb. and have never fouled a plug yet. I don't know about zukes but the honda parts are getting harder to come by so the extra oil is just piece of mind. I never had a sieze from too much oil. And I know my crank bearings are well lubed. Just for the record I never had a problem at 32:1. Does it start pretty easy? Do you need to use the choke alot? Like do you need to keep the choke open long during initial warmup, or can you choke it, start then close the choke and feather the throttle to warm it up? I am not familiar with lt carbs. as far as the specifics but to clean the pilot jet remove the carb. flip it upside down take the bowl off and look for a round brass thing should be 2 those are the jets the one you're looking for can be removed with a screwdriver it has a hole down the center with holes also on the sides part number 19 http://www.gssuzuki.com/fiche_sectio...1985&fveh=1824 I had a problem with my 250r it would bog just before it hit the powerband and then take off could never figure it out till I did a rebuild and then found my reeds had a hole in them, replaced the reeds and the problem went away

 

Replacing reeds sounds cheap, so might as well. The choke has to be on for every startup and any throttle i give takes it out of choke. Then i feather it to warm up which takes choke off and it takes forever to warm up. I'm talking about the needle. I took the top two screws of the carb off and it allowed the throttle cable to separate from the carb and than there was a spring, this black piece that let air in when the throttle was pulled. This spring keeps it all down with throttle release i think. If i didn't say it before very hard to start.

 

With the last detail you added I would look at the pilot jet or reeds.

 

I have never had a problem with that spring, before going as far as the reeds I would first try the pilot jet. remove it and spray it with carb. cleaner and run a piece of wire through all the holes till you can see clearly through them then see what happens and go from there. Also get a new spark plug and fresh premix. 2 strokes can be very finiky, the least little thing can throw them off.

 

Also check to see if your coolant is bubbling. When it's cold take the radiator cap off start it and see if the coolant is bubbling, not flowing like it should but actual bubbling if so you may have a head gasket leak.

 

I checked the coolant, looks good. New spar plug new premix and gas can was just cleaned. The carb has a needle and a pilot jet? Aree reeds hard to get to?

 

Carb. has a pilot or slow jet, needle jet, and main jet. Pilot or slow jet is for idle to approx 1/4 throttle, needle jet from approx 1/4 to 3/4 throttle, and main jet from approx. 3/4 to wide open. The main jet will be next to the pilot jet in the center of the carb. when you take the bowl off. The pilot jet will be just to the side of the main jet. Reeds are not hard to get to but I know Honda's have a tendency for the bolts that hold the reed cage in to break off if it hasen't been rebuilt in a while. The reeds are inbetween the carb. and the cylinder.