If you do have to bore or if you choose to bore out the cylinder I would only bore out what you need to clean the sleve and save the other bores for when you may need them. Also I would go with a lighter forged aluminum piston like weisco they make a good piston and are highly recomended. You may also want to check and see if you carb isn't pluged with anything or clean it and see if it don't start.

 

yeah, I forgot to mention the the wiseco piston thing.....a piston I think will run you about $100

 

Also I would make sure that when you get your cylinder bored out that you have them bore it out to the piston to make sure that you have a perfect fit in your cylinder. Also you can get a great deal on ebay for the piston kit which includes piston, c clips, wrist pin, and decals. I paid 73.00 for mine it was for a .040 size piston....

 

Great suggestions guys, thanks a bunch [img]i/expressions/face-icon-small-smile.gif[/img]

About the carb, yeah, I am definitely going to try to clean it out before spending any money. If thats the issue, then so be it [img]i/expressions/face-icon-small-smile.gif[/img]

I still want to eventually rebuild the engine though.

One last question, the guy I bought it from said the oil was leaking pretty bad, so he just put 2 stroke oil in with the gas. Is this ok? Also, after fudging around with it a bit last night, I went out there this mornin, and there was a couple drops of either gas or oil (maybe both) on the floor... where should I look for leaks?

 

There are a coulple of after market products that will alow you to premix your fuel with oil rather than have your oil injection do it. You could pick one of these up at HPD, or Hotseats performance.

 

Welcome to the forum! You can sure get a wealth of information on here.

I'm going to stick my nose in here - the guys have given you some pretty good advise although I don't totally agree with the wiseco piston suggestion - I don't like, and have never liked, the wiseco pistons for my own reasons. The price of a piston will stay pretty much the same unless you try to go to a "radical" sized piston (example = $70 for STD, .010, .020, etc - $80 for .080)

First thing you need to do if you are going to tackle this job is to get a shop manual - it is a huge help - one from polaris may be hard to come by, but there are some other good manuals out there (ie Haynes / Clymer)

A good machine shop will bore your cylinder, and the Dallas area should be loaded with shops that will or can get it bored. Average price for a cylinder bore is $35 - $50, and it should not matter to them what size you are going to - they have no clue what size it is vs. what you are boring to (ie STD to .040" over), the only thing you are going to give them is the cylinder, the new piston, and information of the piston skirt to cylinder wall clearance specified by the piston manufacturer. The only other thing my machinest asks is that I remove the head studs from the cylinder - he even cleans the old gasket material off of the cylinder for me.

Before you go into the engine - I would make it run and see if it is worth spending any money on - the tranny on the old models was bad about engaging in forward or reverse ($$$ to fix), clutches may be worn out ($$$), and other things.

Now you are probably wondering how to make it run before putting money into the engine
- from what you've said, you've almost had it running - that means the compression is probably low, and maybe some carburetor problems
- - clean the internals of the carburetor with some spray carburetor cleaner - make sure you can spray the cleaner through both of the jets inside - if they are plugged it won't run
- - then pull the spark plug out and pour a little motor oil (10w30, 10w40, what ever) into the spark plug hole - this will "fill in" the gaps enough to usually make them start and run - if it is low compression, the quad will continue to run and the heat generated by the engine will expand the metals and compression will raise while it is running
- then test the quad out to see if there are any other problems with it before determining what you are going to do about it.

 

Ok, so just got done takin the bike apart.

1) Carb is in great condition. I couldnt find anything clogged, etc... Floats were in good condition, etc...
2) Spark Plug is sparking
3) Gas is on the end of the spark plug...

So now, I just have to find a compression tester and test that... what happens if the compression is good? What else could it be?

 

anyone? [img]i/expressions/face-icon-small-smile.gif[/img]

 

Just a quick question. I have an 1985 trailboss in prefect runing condition but my start won't turn over the engine. So I need to pull start it every time. I'm hoping you didn't go threw all that trouble just for a bad starter?