hi all, i know this is a long post but i need some serious help [img]i/expressions/face-icon-small-smile.gif[/img]

heres what is happening. first i am getting gas out the over flow tube just a lil bit so i have been leaning out the floats and it seems to be getting better. i replaced the needle and seat with new ones. (i have taken the carb off push the floats up and have blown into the carb to make sure there is a good seal with the needle and seat and there is)
the plug is new as of today and shows that the carb is running rich. so i lowered the floats even more to try and correct this. floats are NOT deterrated and do not have holes (water tested no bubbles) carb has been cleaned and inspected all rubber gaskets are in good condition.i have adjusted the valves to proper book specs at top dead center. engine and trans are properly spaced out and belt is properly engaging.

now the other problem of what is going on..
the motor sounds like its not reaching top RPM (possibly cause the richness) also there is a fine mist that is coming back out the carb and into the air box when accellerating the engine in neutral or in drive. also after rebuilding the carb and replacing everything, in order for it to start i have to put my hand over the carb as if it were a choke and let it suck for a turn of the engine and it kicks over and almost starts and leaves a nice splash of gas on my hand. ?? after that it will start right up but if i dont do that and try to start it, it will just turn over and never fire like its going to run...

so obviously if there is fuel coming out the over flow the floats are still to high which is odd cause i feel that i have adjusted the needle tang very high. ?
next why is there a mist of gas coming back into the air box? is this a cam issue that the valves are not staying open for the right amount of time and blowing it back thorugh the carb?

please help me out and ask me any questions that may help thanks
also does any one know what compression test on engine should show?
thanks

 

also what about a timing issue? with the cam chain tensioner?

 

Sounds like you have two problems.

First your intake valves are tight. Adjust the valves.

Also your slide needle and nozzle in the carb are worn out.

 

thanks for the reply i have adjusted the valves both exhaust and intake to book specs. and as for the carb ill check that tonight.
thanks again

im going to run a commpression test and see if there is a bent valve. or timing issue. i check the igntion marks and they line up with each other. i have not put a strobe to it yet because i do not have a portable RPM reader.

 

hey everyone found something else out that may help. went ahead and checked the valves again just for the heck of it, and thought id take a closer look at the cam. i noticed that when i turned the engine over the exhaust side valves did not move as much as the intakes, about half the distance. so i looked at the lobe and it appears to be worn. it is not polished like the intake lobes are. its got a grainy look to it. and i noticed also that on the side of the lobe there was metal shavings.

so my question is would this exhaust cam lobe being worn out cause the gas to come back out the carb. also i am wondering if this would some how pressure the carb bowl and cause gas to come out the over flow which one would think it was a float problem when it really wasnt?

oh also does any one have any good info. on a new cam i wouldnt mind going bigger [img]i/expressions/face-icon-small-smile.gif[/img]

thanks

 

Set your carb back to specs and get you a cam.
You can find good used 500HO cams on Ebay cheap or a new one will run around $160.
Aaen makes a bigger cam but you need more than that to make it work right.

 

You found the problem. Replace the cam and rocker arms and start changing your oil more often.

If you are using Polaris oil you should change it about twice as often as they recommend.

You will still need a slide needle and nozzle if your machine has over 3,000 miles on it.

 

thanks guys im ordering the cam today. once i figured out it was the cam i started looking at all the posts about cams and the 500's guess it was a bad batch of them that went out. someone did post that there was a recall on the sp500 at one time. to bad i cant get in that. oh also didnt the cam i have only have one oil hole while the new ones that they came out with had 2? i think i read that some where as well. anyways im headin out to the garage to start tearin it down. im going to take the head off too and check the cylinder for wear and wall marks may even pull the jug and put a new hatch and piston rings in it depending on how bad it is.

what about massaging the head walls? maybe a lil port and polish? any thing i should watch out for, figure id do it while waiting on the cam [img]i/expressions/face-icon-small-smile.gif[/img]
let me know thanks

 

If it is not smoking and using oil leave the rest of it alone. You will only be wasting time and money. Don't fix whats not broke.

 

well i took the head off and everything looks good. valves are not bent, or nicked at all. cylinder walls are clean no scratches which is great cause i didnt really want to have to take the jug off. im going to go ahead and lap the valves and flush the engine oil. i hope that filter got all the shavings i think im going to cut it in half after i take it off and see how much it really got.

oh also i bought a stock cam cause the other cam i was looking at i was going to have to bump the compression with a piston swap.