redneck666 Posted December 14, 2009 Report Share Posted December 14, 2009 (edited) hey guys, heres the problem, i give my sled full throttle she'll usually go. then other times it will go but there is a loss of power. could this be from the jets? because the jets i have are apparently are the wrong ones. i forget what size they are but the size that are supposed be in the are: #40 pilot and #140 main. or could it be i have a gasket leak? those are the 2 problems im thinkin of. its also running on last years fuel that was transferred back into the sled from the boat. it did the same thing last year with fresh pre mix gas in it (mixed to manufacturer specs). so anyone got a clue as to whats goin on here? BY THE WAY, the jets in there now are 250 main and 25 pilot. so sounds to me like its the jets, anyone else agree? and also the sled is a 1981 citation 3500 with a 377 rotax. thanks, JP Edited December 14, 2009 by bigredneck Link to comment Share on other sites More sharing options...
limeyangler Posted December 15, 2009 Report Share Posted December 15, 2009 I've sent you a PM Link to comment Share on other sites More sharing options...
JohnF Posted December 15, 2009 Report Share Posted December 15, 2009 (edited) hey guys, heres the problem, i give my sled full throttle she'll usually go. then other times it will go but there is a loss of power. could this be from the jets? because the jets i have are apparently are the wrong ones. i forget what size they are but the size that are supposed be in the are: #40 pilot and #140 main. or could it be i have a gasket leak? those are the 2 problems im thinkin of. its also running on last years fuel that was transferred back into the sled from the boat. it did the same thing last year with fresh pre mix gas in it (mixed to manufacturer specs). so anyone got a clue as to whats goin on here? BY THE WAY, the jets in there now are 250 main and 25 pilot. so sounds to me like its the jets, anyone else agree? and also the sled is a 1981 citation 3500 with a 377 rotax. thanks, JP I'd sure be looking at the jets. The air can cause differences and major cold and humidity levels might be compensating for the weird jetting. When we were racing 2 strokes we'd always be playing with the jets, particularly on the Mikunis. I had a board drilled that I carried all the time at the races. It had a full range of jets. I would usually only change 10 increments at a time. Are you sure your sled hadn't been running on Nitromethane? JF Edited December 15, 2009 by JohnF Link to comment Share on other sites More sharing options...
redneck666 Posted December 15, 2009 Author Report Share Posted December 15, 2009 (edited) I'd sure be looking at the jets. The air can cause differences and major cold and humidity levels might be compensating for the weird jetting. When we were racing 2 strokes we'd always be playing with the jets, particularly on the Mikunis. I had a board drilled that I carried all the time at the races. It had a full range of jets. I would usually only change 10 increments at a time. Are you sure your sled hadn't been running on Nitromethane? JF lol, i did pull that engine outta a race sled though. it came with the mikuni carb and custom made pipes (swapped them for original)...... long story short she runs good for her age and i just ordered what seem to be the right jets this time. and im pretty sure it is gettin too much fuel cause of the jets. and btw i have no clue when it was last rebuilt. JP Edited December 15, 2009 by bigredneck Link to comment Share on other sites More sharing options...
Dara Posted December 15, 2009 Report Share Posted December 15, 2009 Pull it off, get a gasket kit, put the right jets in and go from there. You still have a couple weeks to wait for ice so get it right Link to comment Share on other sites More sharing options...
redneck666 Posted December 15, 2009 Author Report Share Posted December 15, 2009 (edited) funny story too..... me and my buddy were out on one of our warmer rides. there was a crack in his rad line, we didnt notice so we were givin 'er up a hill then his kitty started smokin (1995 arctic cat zr580). so he shut it down right away. i gave him my sled to go to his house and pick up some more fluid. he got back we filled it up and went back to his house which we only made it about 5 mins. away from. next time we went out he was headin towards me cause i was stopped and waiting for my sled to cool down. next thing ya know he stops dead..... no spark. so he just left it in his garage till last week. replaced his wires and plugs and it was sittin idoling in his garage, when it started smokin again (no coolant leaks this time) im not sure what else happened but now he has to replace 2 pistons 2 sets of rings and 2 chrome sleeves...... well i thought it was funny haha. JP Edited December 15, 2009 by bigredneck Link to comment Share on other sites More sharing options...
JohnF Posted December 15, 2009 Report Share Posted December 15, 2009 lol, i did pull that engine outta a race sled though. it came with the mikuni carb and custom made pipes (swapped them for original)...... long story short she runs good for her age and i just ordered what seem to be the right jets this time. and im pretty sure it is gettin too much fuel cause of the jets. and btw i have no clue when it was last rebuilt. JP Seriously, I'm way out of touch with racing but back in the day there were guys running trick fuels in their sleds. I remember a guy came to me bragging about the great deal he got on a still in the box Motoski factory race sled. It was a nifty unit but he couldn't get it to run right. The carbs were jetted all wrong for regular gas. Do any of you other oldtimers remember the smell of Klotz and the snapping of your eardrums when you stood near to a full on race sled? JF Link to comment Share on other sites More sharing options...
ecmilley Posted December 15, 2009 Report Share Posted December 15, 2009 with any 2 stroke the first thing i would do is a compression check if it checs out ok then jets or carb floats could be the culprit, but it could also be a build up of moisture in the fuel tank, and on a sled that old i would be checking the drive belt and the primary and secondary clutches for correct operation cause it sounds to me like the sled may be choking on the belt Link to comment Share on other sites More sharing options...
redneck666 Posted December 16, 2009 Author Report Share Posted December 16, 2009 (edited) with any 2 stroke the first thing i would do is a compression check if it checs out ok then jets or carb floats could be the culprit, but it could also be a build up of moisture in the fuel tank, and on a sled that old i would be checking the drive belt and the primary and secondary clutches for correct operation cause it sounds to me like the sled may be choking on the belt everything you just stated is fine. except for the jets, the main is over sized and the pilot is under... i think. whatever 25 pilot and 250 main is, compared to 40 pilot and 140 main, lol. and JF i pulled that motor out of a motoski. 1982 mirage 2 i think it was. anyhow i trashed the motoski chassis and kept a few spare parts cause that body and tunnel were rotted right through..... specially if u can put a screw driver through the belly pan with very minimal effort. ordered my jets and a few other things from royal distributing today so they'll hopefully be here in the next couple of days. crappy thing is, the ski-doo dealer up here went back to just contruction equipment cause they had a problem can-am ski-doo and bombardier company. goodish thing for me is i get my parts for dirt cheap. JP Edited December 16, 2009 by bigredneck Link to comment Share on other sites More sharing options...
JohnF Posted December 16, 2009 Report Share Posted December 16, 2009 everything you just stated is fine. except for the jets, the main is over sized and the pilot is under... i think. whatever 25 pilot and 250 main is, compared to 40 pilot and 140 main, lol. and JF i pulled that motor out of a motoski. 1982 mirage 2 i think it was. anyhow i trashed the motoski chassis and kept a few spare parts cause that body and tunnel were rotted right through..... specially if u can put a screw driver through the belly pan with very minimal effort. ordered my jets and a few other things from royal distributing today so they'll hopefully be here in the next couple of days. crappy thing is, the ski-doo dealer up here went back to just contruction equipment cause they had a problem can-am ski-doo and bombardier company. goodish thing for me is i get my parts for dirt cheap. JP Well, good luck with the fix. Let us know if the new jets work out. JF Link to comment Share on other sites More sharing options...
backbay Posted December 16, 2009 Report Share Posted December 16, 2009 This brings back alot of memories, mostly motocross. Speaking of racing aroma, I was Bel-Ray man myself, but when I started, there were still guys mixing Castrol R, which was fabulous! I would check the jets, the float valve, (very prone to sticking after prolonged inactivity), and anything else that could be subject to gumming up. A 140 main vs a 250 stock main is a very lean switch: Check the colour of your spark plugs.... Link to comment Share on other sites More sharing options...
ecmilley Posted December 16, 2009 Report Share Posted December 16, 2009 everything you just stated is fine. except for the jets, the main is over sized and the pilot is under... i think. whatever 25 pilot and 250 main is, compared to 40 pilot and 140 main, lol. and JF i pulled that motor out of a motoski. 1982 mirage 2 i think it was. anyhow i trashed the motoski chassis and kept a few spare parts cause that body and tunnel were rotted right through..... specially if u can put a screw driver through the belly pan with very minimal effort. ordered my jets and a few other things from royal distributing today so they'll hopefully be here in the next couple of days. crappy thing is, the ski-doo dealer up here went back to just contruction equipment cause they had a problem can-am ski-doo and bombardier company. goodish thing for me is i get my parts for dirt cheap. JP well since you know everything what was the question again? Link to comment Share on other sites More sharing options...
JohnF Posted December 16, 2009 Report Share Posted December 16, 2009 This brings back alot of memories, mostly motocross. Speaking of racing aroma, I was Bel-Ray man myself, but when I started, there were still guys mixing Castrol R, which was fabulous!I would check the jets, the float valve, (very prone to sticking after prolonged inactivity), and anything else that could be subject to gumming up. A 140 main vs a 250 stock main is a very lean switch: Check the colour of your spark plugs.... I first became addicted to the smell of Castrol R at the sports car tracks. The guys were running it in their crankcases. Incredible smell. Klotz will always be second in my heart. I ran it in my trail sleds, too. JF Link to comment Share on other sites More sharing options...
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