1985 Vmax
Posted: Thu Apr 03, 2008 4:58 pm
I pucrhased this sled 3 seasons ago for $600
1985 Vmax
The first season was amazing i had it doing over 90 MPH on Lake Superior, it was a cold year so it was very responsive on the throttle. I discovered later that the main jets were 320 which is too fat. I ended up rolling the sled on the lake, i skidded sideways over a pressure crack the track hooked the ice and it flipped over on me. and rolled it 1 1/2 times lol it kinda hurt, I was limping for 2 weeks. That was the last ride of the year i put it away for the winter shortly after. The next year when i went to take it out for the first time it started running crappy fouling plugs etc. Finally a quick compression check tells us no compression on 1 cylinder. Thats when the fun began so to speak. We took the engine out and started to tear the top end down, this was a chore , We had to retap a few things and use heat. Once the cylinder came off we found that one piston was toast it had chunks of metal stuck on the top of the piston, and embedded in the cylinder head, with stuck rings. This was a shame because i have Wiseco Pro Lite pistons in it, not cheap. The cast sleves had some scoring as well. We cleaned it all up scraped the heads out cleaned out the bottom end with air and put a new wiseco piston in it. The first try after the rebuild and it run like crap. After trying to get it to run for like 1/2 hr the engine flooded solid with fuel. Scratching our heads again and trying to get it going we found a fuel problem. THE DIAPHRAM IN THE FUEL PUMP HAD A HOLE IN IT AND THE GAS WAS GRAVITY FEEDING THROUGH THE DIAPHRAM AND INTO THE BOTTOM END THROUGH THE IMPULSE LINE. We fixed that, fuel flow was excellent but now we have a spark issue. Tried new plugs, coil with no luck. Out comes the volt meter a few checks thanks to the VINTAGE VMAX WEBSITE and the SPECS. we find a bad stator coil. I looked around here for one and no luck. This year i decided to contact CHUCK , he has tons of Vmax parts for us guys in need. Thanks again buddie!!!!!! Now were happening, good fuel good compression and good spark. Now this sled starts easier than most, 1/2 a pull if the engine is warm 1 to 3 pulls when cold with the choke on. WE go for a ride and only getting 7000 rpm, scratching our heads again i decide to rejet the carbs to 300 a little fat but closer to what it should be. WE tighten up the secondary spring to 18 lbs now i,m gettin about 7200 still too low. Ok now what, so off with the primary clutch to find that all the bushings are shot, instead of buyuing the wafer bushings from the dealer we decide to get OILLYTE brass and make them on a lathe. Having done this and a new spring from an exciter, we lossened the secondary to 14 lbs, now were doing 7600 rpm. This was better but something still wasnt right.We decide to try a P-85 clutch from a Polaris. I go to start the engine to bring it into the shop and the damn thing locks up, i cant pull it over now!!!! I try rotating the clutch by hand and after moving it back and forth and get it to unlock. Not wanting to believe whats happening i take it for a short ride and its doing like 6000 rpm not good! We now pull the engine out and completely tear it down. Now we know why its running crappy . 1 bad mag seal and pump drive crank bearing, crank is out of round 60 thou. on i end and 30 thou on the other. WE change all the end bearings both ends. Open up the pump drive and find anitfreeze in it which is leaking into the stator, all the seals are toast and in need of new bearings as well, the idler gear has no balls left in the bearing and its been chewing up the case. I now have all the parts to rebuild the pump drive thanks to an awesome machinist buddie and a really good bearing distributor, we cross referenced some bearings and got some from the dealer as well. I have the crank fixed with new bearings, straightened and the bottom end is sealed up back together. Pistons, cylinders are barely worn. This is now April 2008 and the snow will be gone in a week its been 50 to 60 degrees farenheit the snow is going fast. I will continue to systematically eliminate all the problems i can and,hope that next season will be better. I bough a Phazer this year and have gotten in some pretty awsome riding.
stator dissasembled
503 skidoo crank
1985 Vmax
The first season was amazing i had it doing over 90 MPH on Lake Superior, it was a cold year so it was very responsive on the throttle. I discovered later that the main jets were 320 which is too fat. I ended up rolling the sled on the lake, i skidded sideways over a pressure crack the track hooked the ice and it flipped over on me. and rolled it 1 1/2 times lol it kinda hurt, I was limping for 2 weeks. That was the last ride of the year i put it away for the winter shortly after. The next year when i went to take it out for the first time it started running crappy fouling plugs etc. Finally a quick compression check tells us no compression on 1 cylinder. Thats when the fun began so to speak. We took the engine out and started to tear the top end down, this was a chore , We had to retap a few things and use heat. Once the cylinder came off we found that one piston was toast it had chunks of metal stuck on the top of the piston, and embedded in the cylinder head, with stuck rings. This was a shame because i have Wiseco Pro Lite pistons in it, not cheap. The cast sleves had some scoring as well. We cleaned it all up scraped the heads out cleaned out the bottom end with air and put a new wiseco piston in it. The first try after the rebuild and it run like crap. After trying to get it to run for like 1/2 hr the engine flooded solid with fuel. Scratching our heads again and trying to get it going we found a fuel problem. THE DIAPHRAM IN THE FUEL PUMP HAD A HOLE IN IT AND THE GAS WAS GRAVITY FEEDING THROUGH THE DIAPHRAM AND INTO THE BOTTOM END THROUGH THE IMPULSE LINE. We fixed that, fuel flow was excellent but now we have a spark issue. Tried new plugs, coil with no luck. Out comes the volt meter a few checks thanks to the VINTAGE VMAX WEBSITE and the SPECS. we find a bad stator coil. I looked around here for one and no luck. This year i decided to contact CHUCK , he has tons of Vmax parts for us guys in need. Thanks again buddie!!!!!! Now were happening, good fuel good compression and good spark. Now this sled starts easier than most, 1/2 a pull if the engine is warm 1 to 3 pulls when cold with the choke on. WE go for a ride and only getting 7000 rpm, scratching our heads again i decide to rejet the carbs to 300 a little fat but closer to what it should be. WE tighten up the secondary spring to 18 lbs now i,m gettin about 7200 still too low. Ok now what, so off with the primary clutch to find that all the bushings are shot, instead of buyuing the wafer bushings from the dealer we decide to get OILLYTE brass and make them on a lathe. Having done this and a new spring from an exciter, we lossened the secondary to 14 lbs, now were doing 7600 rpm. This was better but something still wasnt right.We decide to try a P-85 clutch from a Polaris. I go to start the engine to bring it into the shop and the damn thing locks up, i cant pull it over now!!!! I try rotating the clutch by hand and after moving it back and forth and get it to unlock. Not wanting to believe whats happening i take it for a short ride and its doing like 6000 rpm not good! We now pull the engine out and completely tear it down. Now we know why its running crappy . 1 bad mag seal and pump drive crank bearing, crank is out of round 60 thou. on i end and 30 thou on the other. WE change all the end bearings both ends. Open up the pump drive and find anitfreeze in it which is leaking into the stator, all the seals are toast and in need of new bearings as well, the idler gear has no balls left in the bearing and its been chewing up the case. I now have all the parts to rebuild the pump drive thanks to an awesome machinist buddie and a really good bearing distributor, we cross referenced some bearings and got some from the dealer as well. I have the crank fixed with new bearings, straightened and the bottom end is sealed up back together. Pistons, cylinders are barely worn. This is now April 2008 and the snow will be gone in a week its been 50 to 60 degrees farenheit the snow is going fast. I will continue to systematically eliminate all the problems i can and,hope that next season will be better. I bough a Phazer this year and have gotten in some pretty awsome riding.
stator dissasembled
503 skidoo crank