- Location
- North Jersey
What the most compression I can get from a stock bore 760 62t motor on pump gas?? Dome size suggestion
760 compression
- Thread starter dirtyjrzy
- Start date
- Location
- North Jersey
Stock bore. I plan on getting a B pipe. I plan on doing the head and the proper already have that's it ain't doing anymore.
- Location
- Red Bluff CA
I've ran 220 psi on a dasa for a season. It was a very noticeable difference in power. I ran it on 100ll and never had a issue. I recently went back down to 180. Not as big of a hit on bottom, but still plenty powerful.
A 760 crank uses the same bearings without the added load on the sides of the piston cause by a 10mm stroke. So if you can keep the head and cylinder attached to the cases. And have access to decent fuel. No reason you also couldn't run 230
A 760 crank uses the same bearings without the added load on the sides of the piston cause by a 10mm stroke. So if you can keep the head and cylinder attached to the cases. And have access to decent fuel. No reason you also couldn't run 230
- Location
- North Jersey
I used to run 215 compression in a 701 on aviation fuel when I raced it was a bullit
- Location
- North Jersey
- Location
- Red Bluff CA
I've broken 3 61x cylinders from running 180 psi. One was with a girdle. I think the 760 and 62t cylinders are alot stronger and dont have that problem.
- Location
- Wichita ks
Broke my 760 on my race ski couple weeks back . 180 with non girdle lasted 3 season of racing.
Attachments
Leave that head on there as long as it seals good. Get the pipe and concentrate on getting the pump load right. You need to see 7000 rpm or more. Its really amazing how much response and acceleration you can gain from boring the nozzle and just slightly bending impeller blades. Most riders get on the high compression bandwagon and end up melting pistons and breaking cylinders.
- Location
- Red Bluff CA
All mine broke on the intake side front cylinder also. Mine broke at the base of the cylinder tho. It always seemed to happen after extend high throttle runs. Sucks to see even the 760 can't handle it. They are usually fixable if a guy wanted to take the time.
- Location
- Charlotte, NC
Was that 760 cylinder that cracked running a stock 61x pipe for lites racing when it cracked? I have a later 62t cylinder with the added gusset that I had fully ported running 195psi with a non girdled ada head. I am not racing though and don't do extended full throttle runs. I'm not running a pipe that bolts to the head either. I'm asking because I'm curious if it's the stock exhaust that bolts to the head that actually causes the cracking. I understand the 61x cylinders are much thinner in that area and if i was running a 61x cylinder, I'd definitely get a girdled head
- Location
- Red Bluff CA
All my 61x cylinders were running b pipea when they broke. 2 had recut stock heads. One had ada girdled head. I also have a blaster with a 62t 701. 185 psi. And it's been fine for years now, although it doesn't get rode often, when it does its lots of wide open runs. B pipe mod
- Location
- Wichita ks
This was running a b pipe , I did notice that one of my dome o-rings looked damaged on that bore . I’m wondering if it was leaking and it pressurized the cooling passage with compression of the cylinder causing the failure.
- Location
- OR
- Location
- Red Bluff CA
Multiple 3-5 second blasts in a couple minutes. Like racing or ripping around buoys.
Your high rpm ignition timing would be the limiting factor. It would run forever IF the timing was pulled back enough. All of our rules of thumb are based around the stock fixed ignition timing. At 23 degrees the engine would be detonating at full rpm and would melt down in a few seconds. If you kept it from melting it would probably break the cylinder sooner instead of later. Standups can typically get away with more compression and timing advance than a sitdown. Freestyle skis can get away with a really hot combination.