Okay so to give a little back story i was given this four wheeler for free. So even if its going to take a few hundred dollars to get it running correctly im probably down for that, i just need a few suggestions. Now i work on cars and have attended tech school so i sort of know what im doing its just that the systems on the ATV are kind of foreign to me. Back to the four wheeler in question, it is a 93 blaster when it was given to me i was told it had no spark and that is why it didnt run well it sat a while (almost 2 years) before i got any ambition to try and fix it and when i did it was simply a crossed wire preventing the spark so thinking i had the problem licked i tried to fire it up with no luck, i then assumed i had a weak spark so i cleaned the inside of the flywheel (magnets) with some emery cloth until they were shiny and clean as a whistle and replaced the coil plug and plug cap still have spark still no start i measured compression and read about 75 psi is this low for this i know a car would probably run (at least a standard compression engine) although it would be a little low and if this is low what would you guys recommend rings and hone like on a car or is there something im missing? also i tried pulling it in gear behind another ATV with no luck but i noticed at that point that the clutch doesnt seem to do much to disengage the engine from the tranny and it doesnt seem to want to shift while moving and a stand still it seems to shift fine (maybe a little hard to move the shift rod) <BR> so if you dont want to read all that my questions are why cant i shift while moving and is 75 psi too little compression and if so how do i fix it... rings?
Sorry if I simply reiterated other peoples questions that I'd like to thank you in advance for any help you can offer
Has this quad just been sitting around? If so, keep in mind that to do the compression test you need to hold the throttle wide open to allow air flow into the engine. Also, if it has been sitting around and it has a FILTHY filter, take the filter off and kick it over with the throttle open and take the compression reading. Probably stuff you already know, but important to keep in mind.
Compression varies depending on who you talk to, but generally if you are below 110psi(or around there) it's time for a rebuild. Ideal compression is 120-140psi.
If you still have no spark, it might just be a bad CDI box. There are numerous places to get replacement ones. Look at the plug boot too as it actually just slides on to the wire. The part that plugs to the top of the plug is just a rubber housing with an extension from the wire....you can pull it right off the wire, so check and make sure it's connected. Other things to check are the kill switch wiring on the left handlebars, and on/off switch.
While you are working on it, replace the filter if it is dirty. Uni filters are cheap and easy replacements. You will have to oil them(I use PJ1 spray oil), but they flow some more air as well. An always important thing once you gain spark is to take the carb apart and clean it. If it has been sitting for a while, they get gummed up like no other. It's nothing complex and easy to take apart.
http://www.blasterforum.com/do-yourself-20/how-clean-carb-36600/
I wouldn't recommend pulling it. If it has no spark, it's pointless to do anyways. Plus buying it as a "junker", I wouldn't be surprised if it needs a rebuild(hopefully not). It could prove dangerous because when careless owners just ride them without checking compression, they tend to get more piston slap from the cylinder to piston tolerances and the piston skirts break off and can get down in the crankcase........a good reason not to try to pull start a quad that doesn't want to start on what you have described so far as low compression. On the plus side, if it's just a top end that needs rebuilt, with Blasters, it's dirt cheap.....send it out, get the cylinder bored to oversized spec, and buy and oversized piston/top end gaskets, and reassemble yourself. Shouldn't cost much over $100 to do if you have a good local machine shop.
