1996 spx

[chuckydoo]

Well, Its been 6 weeks and alot $$$$ and i still can't get this thing to run right. I bought the ski not running and the engine out and top half off. The pistons were scorded and cylinders gouged pretty good. So I did a top end, put it together and would not idle well and had the runaway throttle that would just take off and WOT till you pulled the lanyard. Also smoked badly. After talking to some people in the business I removed the engine and replaced the Crank. Put it back in and same problem. Took it back out, pressure tested the engine and found it to be leaking badly. It appeared to be leaking into the rotory valve shaft area. That would explain the smoking. I called the place I bought the crank from and they told me I must have received a bad crank and sent a replacement. I put the new crank in and put it back together and guess what, same problem. I removed the engine again pressure tested and found it to be leaking from the crank case where the halves meet on the surface of the Rotory valve. So, I split the cases again sealed real good this time using three Bond 1211 as was recommended. Pressure tested again and tested fine, i tested both the crankcase adn the rotory valve shaft compartment and both held 10psi for 20 minutes. Put the engine in yesterday and same problem, idle not constant and if i rev it a few timesit will take off again uncontrollably. I realize its a lean condition but I am at a loss where to go from here. I had the carbs apart and replaced the grey line and cleaned the fuel valve already. Any help would be appreciated.

 

[nswillin]

Man, that's a lot of work. Who knows what that engine has been through before you got it. If it was me I would've just pulled the engine and replaced the whole thing with a reman. Probably come out a little cheaper.

 

[chuckydoo]

hindsite is 20/20. I would have been better but once you get into it its hard to stop. I'm not sure I would'nt have the same problem right now because i am confident that the engine rebuild is right it may be in the fuel system now.

 

[nswillin]

I heard that.
Maybe try the leak down test on the carbs as well to test diaphragms. Then do a separate test on the needle and seat to see if air is getting by the seat.

 

[chuckydoo]

Good plan, I will try tomorrow, I think I can use same leak tester

 

[nswillin]

Yeah it will be a piece of cake after doing the engine.

 

[chuckydoo]

I was also advised to check the whole fuel delivey system by bypassing the fuel valve. I was told to disconnect line from carb to filter and connect direct to reserve line on tank.