Hello all,

I just inherited a mess of an atv from my dad last week and am trying to get it to run. Hopefully someone on here can help me with my issues. I was given one complete atv and one partial atv. As far as I can tell, the frame of the complete model is a 1989 Trail boss Model W897527 2x4. The Model of the engine (currently in it) is an EC25PF-04 (244 CC) and the number is 88-0067. The engine that is in the complete model was assumably taken from the partial atv. The carburetor that is on the complete model is a 38 mm Mikuni VM with a 240 main jet (not sure about pilot jet, but i am assuming it is a 45). After looking through the parts diagrams on a website, the 38 mm carb that is on there seems to match the 88 trail boss 250 (model X888528). I am not sure as I was unable to find a model number on the partial frame. The carburetor that came of the 1989 engine (model EC25PF-05) is a 30 mm mikuni with a 145 main jet.

I cleaned the 38 mm carb that was on there and put it back onto the motor. I try pull starting and its not starting. I checked for spark and I am getting spark. I pulled the plug and there is wet gas on the electrode (more than there should be). I checked the compression and it gets up to 120 psi after two pulls.

My question is this, is the 38mm mikuni too big for the engine causing too much gas to enter the combustion chamber? Or is it something simple that I am missing on the carb itself or something else that would cause too much gas?

Any recommendations on the number of turns the air adjuster screw should be out? Currently it is at 1 1/2 turns.

If there is any other information that would be helpful, let me know. Thanks for the help.

Andy

 

it is th right size you probaly have a internal problem

 

is it electric start email me at fishandfreak@yahoo.com if you further questions

 

it has an electric start button, but it doesnt work so i am using the pull start. They may not have hooked it up with the engine swap. thanks for the responses.

 

anytime send me pics if you have some and are you intrested in selling it or parting it out becuz i have the same bike i also have a 2006 polaris outlaw

 

go to worldofpowersports.com it is the best site to go to and that is were i would go if i was you

 

thanks. I wont be selling the complete one (unless i cant get it to run), but i may be parting out the other one depending on how a rebuild goes and if there are enough parts for another complete quad.

 

Since the engine is out of an R/ES model w/38 mm carb its port timing is different than the 30mm models as I understand it and they were susceptible to hard starting. I have an 87 non-x model and found that they are very sensitive to spark plug condition. I began having a prob with starting and fouling and found one problem was the spark plug which appeared not to be in bad shape but when a new one was installed it was an immediate difference. I assume during your cleaning you checked the float level-if not do so and replace the needle and seat as these are notorious for problems if the vehicle has sat for any period of time. The other thing I would check is the oil injection to make sure it is set correctly as if somebody changed it it can cause fouling. Hope these ideas help.

 

so what happen did it work

 

well it did start. sprayed some ether directly into the cylinder. It is still hard to start and wont start without the starting fluid. but it runs without the starting fluid. anyone know what the float height is supposed to be on the VM38SS? The clymer manual gives one dimension of 14.5 to 14.7 mm but it is impossible to get the float arms that high due to the tab hitting the float needle mount. The motor also does not idle. I believe that may be the intake boot so I am going to get a new one now that i know the engine runs. Got the starter to work (jumped a couple of wires in the wiring diagram) but it seems to catch and not let go. If you use the pull starter after trying to use the starter, its next to impossible. I am going to pull the starter out and see if needs a cleaning or something is wrong where it wont release. It wont start with the starter, I still need to use the pull string to start it at all.

Anyone know what was so different with the R/ES model and why they put the bigger carb on it?

i also got a new spark plug and still get the hard starts. Hopefully the new intake carb adapter will solve some of my problems.