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Discussion Starter #1
Hello I'm new to the forums and I recently got a 1987 Polaris trail boss I discovered at my friends out behind his pole barn less than a year ago. Since then I have done much work to it because the brake cables where stuck, the transmission had a crack in it the engine was locked up and many other problems. I probably have put more work into it than it's worth, but it gives me experience because I'm only 13, but I am very advanced for my age. Anyway I must pull start it because the electric start is broken and at first it ran great and always started good. Now however it starts very hard in all weather, but it starts first pull in any weather if you just give it a small burst of starter fluid to the carb. I have cleaned the carb and replaced the spark plug, but it still seems to be starting hard and it has always bogged, but I don't know if that is related to the starting hard or not, but I can live with the bogging. I'm thinking it might need a carb rebuild kit, but I'm just having trouble finding one. Does anyone have suggestions on what it could possibly be causing the hard starts? Thanks
 

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First off, welcome to the board!
 

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when you cleaned the carb did you put brand new jets in, and made sure its jetted properly? and also tight valves can cause hard starting
 

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Not sure about the tight valves, but I tried to clean the jets to the best of my ability. I didn't buy new ones because since you can't buy a rebuild kit from the dealer to buy parts separate its extremely pricey. I think this winter I might try to find a carb rebuild kit and replace the piston rings and all the top end gaskets. So hopefully by doing all that, it will fix the problem and also make the engine run a lot better.
 

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First I'd like to not only welcome you to the board, but compliment you on your respectable endeavor ... not too many 13-somethings I know are willing or able to do what you are!

Secondly, I'd suggest you go on to eBay motors and do a search using 'Polaris Trail Boss' ... I think you'll be amazed at what you can find. I own an 89' Trail Boss 250 and the carb. kits on eBay are going for about $20.00 incl. shipping.

Check it out and keep up the good work son! :fing02:
 

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Discussion Starter #6
Thanks for the welcomes and advice. Observer I actually tried ebay several times and I found many parts I need, but all of the carb rebuild kits that I have seen have been for years 89-93. Although my local Polaris dealer said they would rebuild it for $70 which is a little more than I'd prefer to pay, but it's an option. I also thought about trying to find a cheap carb on ebay off a newer Polaris ATV with the 250 engine, which should fit mine and if it's bad at least I can find a cheap rebuild kit for it. Either way I decided that with all of the small problems that I might as well strip the whole ATV down to the frame and fix all of the little problems, rebuild the top end, due some paint work and I don't see why I can't make it last another 23 years.
 

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i will look for a carb rebuild kit for you in my spare time. i know some places to look. how much you looking to spend?

$70 is a fair price to rebuild a carb, it take about 1 hour of shop labor to do it, so i assume the shop is $70 an hour. i understand its more then you want to spend, but its a fair price.
 

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Well I would prefer that the rebuild kit isn't too much over $20-$30. If it's too much more than that for a rebuild than I would probably be farther ahead to have my dealer do it for $70 and know it's done right. Thanks I appreciate your help.
 

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Thanks for the welcomes and advice. Observer I actually tried ebay several times and I found many parts I need, but all of the carb rebuild kits that I have seen have been for years 89-93. Although my local Polaris dealer said they would rebuild it for $70 which is a little more than I'd prefer to pay, but it's an option. I also thought about trying to find a cheap carb on ebay off a newer Polaris ATV with the 250 engine, which should fit mine and if it's bad at least I can find a cheap rebuild kit for it. Either way I decided that with all of the small problems that I might as well strip the whole ATV down to the frame and fix all of the little problems, rebuild the top end, due some paint work and I don't see why I can't make it last another 23 years.
I think you maybe on the right track - looking for an '89 carb that fits your application - then buying a kit for it, if you need too. What size is the engine your running?

Take one step at a time and before you know it your machine will be done and totally awesome! Keep up the good work!

John
 

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try mfgsupply.com most of their kits are under $20. not including freight
 

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try mfgsupply.com most of their kits are under $20. not including freight
Thanks 4getful2 ... for the mfgsupply.com link. Lots of good supplies all in one place ... and the prices aren't bad!
 

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Discussion Starter #12
Well my four wheeler has been down to the frame for a few months now and after waiting for over a month my piston has come in. I was just about to torque down the engine head bolts with new piston in when I noticed that I could move my primary clutch(still on the engine)up and down slightly. When I did this my whole crank shaft would move slightly. Is this bad or typical and can it stay like this and be fine or will it leak. I'm not sure because since it's a 2 stroke it's not like oil sits in the bottom of the engine.
 

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Spikeman ... I'm no ATV expert by any stretch, but I've never see crank movement like you describe that isn't an indicator of a more severe bearing/bushing problem. I'd check your crank support bearings and research some technical specifications before I went any further.

If someone more knowledgeable about these 2-strokes has some additional insight, now would be the time to chime in!
 

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Well my four wheeler has been down to the frame for a few months now and after waiting for over a month my piston has come in. I was just about to torque down the engine head bolts with new piston in when I noticed that I could move my primary clutch(still on the engine)up and down slightly. When I did this my whole crank shaft would move slightly. Is this bad or typical and can it stay like this and be fine or will it leak. I'm not sure because since it's a 2 stroke it's not like oil sits in the bottom of the engine.
The Crankshaft does have some play (called Crankshaft Endplay) but should not be ecessive i will have to look at my service manual to see the specs for your year bike, the reason it is moving is you more than likely you may have bad bearings on the crank, the bearings are the only support inside the crankcase, the bearings allow the crank to only move in your normal rotation any other direction the balls in the bearing are either worn badly or worse they are gone (in that case you need to have a shop check the crankcase halves for warpness and cracks and they may need to check the crank for straightness) you will have to replace both bearings and word of advice have a shop do it because you have to heat the crank case halves up to loosen the bearings up as well you have a to have a special tool to remove the pressed on flywheel, the bearings should run you about $100 to $130. And as for saying there is no oil in the crankcase, there is (only a small amount but still can leak out) thats the fuel sits after it leaves the carb until the piston goes on the downstroke to suck up the fuel mixture The reason i know is i have done several polaris 2-stroke motors including my 1994 polaris 250 trailboss, another thing is you should've had the cylinder bored maybe .20 or .30 over mine trailboss is .40 over and damn it freakin hauls ass, any other questions just message me or if you need a scaned copy of a repair manual section i can do that for you, because i have been and done what you are doing, so Good Luck
 
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