Hello All,
i traded for a 1987 Trailboss 4x4 in rough shape. Im not afraid of a good project but im kind of at a loss.

I have Good spark, good compression, clean carb just to get those out of the way.

It seems it only starts when i put a little starting fluid down the hole and then as i try to get it to rev up it boggs out and dies. if i dont give it anything it dies even faster.

The oil pump oil input was broke off and capped so im running pre mix on this thing as well.

I have had it running a few times for a few laps around in the snow but it only wants to go maybe 10mph if that.

Hopefully someone can help me get this thing started and stay running.

 

all that being said I`d do a compression test on it. you need to have a minimum of 100 psi and at 100psi thats getting on the low side. Make sure the float is set correctly in the bowl if its not allowing enough gas in then it will be hard starting. will the motor rev up in neutral? could be a clutch problem if your only getting 10mph. My personal experience with the 250`s is I would start with the compression test if all checks out I would then go at the crank seals. Hard starting most of the time on the 250`s is because the motor isn`t sucking hard enough to draw the fuel out of the carb. The cause (not enough compression or leaking crank seals) with what you said " It seems it only starts when i put a little starting fluid down the hole" I`d be willing to bet its the crank seals. They are easy to change and a cheap fix the hardest part of the job is taking the clutch covers and clutch off the PTO side of the motor. You will need a polaris clutch puller to get the primary off. and a harmonic balancer puller to get the flywheel off. I can do the whole job both sides disassembly and reassembly in under 2 hours. to get the seals out of there seats I use 2 self-taping screws put into the metal housing of the seal and with 2 sets of pliers I pull the seal out. its an easy job just sounds much harder than it really is.

 

, Ihow much is the compression?.did you disassemble the carb and thoroughly clean all the jets and passages? oops someone beat me to it , I was going to ask about crank seals

 

Thanks guys, as for exact compression i will snag my buddy's compression tester this weekend but hes a mechanic and seems to think there is more than enough compression.
From what im hearing these crank shaft seals are a normal thing on this 4 wheeler. it has sat for quite some time before i got it as well.
I have a harmonic balancer puller so thats no big deal.
I have heard i can use a bolt instead of buying the specific tool to pop the clutch off.
Same concept as popping a flywheel on an outboard off i would imagine.

does anyone have a write up on doing these or any pointers/pictures?

Thanks again guys

 

if it sat for a while I would almost bet its the seals that are giving the problem not allowing enough suction from the motor to get the fuel into the combustion chamber. yes I have heard of people using a fine thread bolt for the clutch. if you plan on keeping the quad I recommend spending to 25 bucks on the proper puller you will need it more than once. the seals are easy if don`e like i said maybe someone else could chime in and give any pointers i may have forgotten.

 

ok well tomorrow while im out im going to get the seals and dive into this thing. I will probably compression test it before....probably. Pending my buddy brings it over but it pulls over pretty heavy.
At any rate ill let you all know how this pans out. Also anyone know the Ft lb torque on the flywheel and the drive clutch bolts?

 

I don`t have my book here but i think the drive clutch torque is around 40lbs what I do is use a wooden broom stick through the clutch and into the foot rest and give it a good crank on and the same for the flywheel. I can get the spec`s for you but that won`t be until the middle of February

 

40 sounds good to me and tanks for the tip! anything to make this process easier

 

i have officially spent more time gettin parts then working on the quad. but i was going to get this done come hell or high water this weekend so no big deal. got my 2 seals ( one at one end of town and one at the other). Of course i wasnt able to find a 7/16 20 bolt to get that clutch out, so ill continue that hunt tomorrow.

As for actual work on the quad.
about 30 mins to take off the clutch cover, recoil cover, flywheel 0and stator.
Ill continue in the AM

 

See easy job glad to hear you have some progress.