11-16-2011, 12:08 AM #1
mods for gp1200r, also looking for parts and info, direction, advise, HELP!!!
Hey guys I usually use Green Hulk as a information website when I have a problem, but now im building a 02 gp12 and I would like some help and direction, here is the scoop, I buy and sell jet skis on the side and have rebuilt pv motors and jet pumps and carbs but am not as performance oriented as you guys are, this is my first year working on skis but i have been a small engine mechanic forever, I got the ski with trailer for 500.00 and knew it had a bad cylinder I boroscoped it before i bought it. I was hoping it was just the jug and piston and tore it down to luckily find that to be the case, started checking and all oil lines were on, so i figured lean seizure, come to find out it was an sbt motor and the #1 cyl was fried, the factory band clamp on the pump came loose, obviously going premix, just ordered off ebay a kit with riva sponsons, ride plate, trim tabs, and intake grate, I have another jug and piston to throw on it, but I would like to do a couple of mods, any ideas? reeds? heads? what to stay away from whats good? also bought a cat delete and chip, should I re jet carbs? the two good piston were black on the top lean I beleive, i have been debating throwing new rings in it as well just to freshen it up.
11-16-2011, 11:44 AM #2
being that it is an sbt motor, they usually sleeve their motors with steel sleaves. and tolerances on their engines a alot more "loose" than a factory built engine. sbt motors are a hit or miss. how much performance are you looking for out of the ski? i wouldnt raise the compression too much. make sure the other cylinder is the same bore as the rest. you will only need to rejet if you add flame arrestors.
11-17-2011, 05:55 PM #3
checked the other jug all at factory spec around 80, Im looking for as much performance possible without porting cylinders, what I would like to do is, Heads, Reeds, single or tripple pipe, maybe aftermarket carbs? and than all the b.s tabs, plate, grate, solas 13/19? pump stuffer, tunnel reinforcement, bilge, bars, tach and gps, then if its not enough ill go with a bigger motor, but I hope ill be satified with that, how fast do you think it will go?
11-18-2011, 03:43 PM #4
- Join Date
- Sep 2011
- Seattle, WA
factory spec is 80? my gp1200r is 120.
Well if you do all that, probably around 76 - 80 depending on how agressive your heads are. (none dream o meter speed)
How fast are u trying to go? i might consider trashing the sbt motor and doing a sho motor swap instead. I dont have any personal expirence with the sbt motor but from what ive read here and what your suggesting you want to do, it isnt going to last.
11-19-2011, 12:02 AM #5
by factory spec being 80 he means the bore size on cylinders.
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