Factory Pipe: ltd vs mod

[Frosty]

It's hard to say because every setup will vary slightly for multiple reasons. It can even come down to the weight of the rider. I would say with all the items you have listed, 3 degrees advanced would be a good starting point. Make sure you run the best gas you can though. Def. keep an eye on things though when you start playing with advance. Things tend to destruct very quickly.

Doug

Cool, thanks for the info Doug. :biggthumpup:

 

[Frosty]

when i ran my 760 with 5mm advance, i just mixed some 100LL gas in. we have a few gas stations locally here that sell all kinds of gas (100LL at shell, and VP gas station with 110 at the pump!!) ... i was also running ~200+ psi at first... but after driving around daytona beach for an hour with yamaslut looking for some fancy fuel, i just got frustrated and ran 92 octane in my boat for the day.. about 12-15 gallons later.. i was still running fine. i eventually backed it down to 180psi/3mm adv when i sold the boat, i didnt want it to blow up on the guy who bought it, but the point is, as long as you are easy on the throttle you can run high psi and advance, even on pump gas, you just have to stay off the throttle.. short 3-4 seconds burst wont deto your motor.. but a WOT run across the lake or bay.. boom. :biggrin:


we went to the school of rotaxgrenade down here (the man, the myth, the legend).. he taught us the ropes of *very* high psi , pump gas, and ignition... his blaster was running like 220psi on pump gas with static adv timing (i'm not sure of exactly how much adv he was running).

that blaster motor is still running strong to this day.. :biggthumpup:


edit: this is more fyi than advice.. none of the above is RECOMMENDED, just food for thought.

Good stuff.. I appreciate the insite for sure. Thanks bro. I live kinda out of the way, my best local fuel is 93 octane around here, unless I buy a drum of the good stuff. I don't do much WOT... mostly less than 3/4. I might play around with it a little. I was also thinking of going to some smaller domes as well. Anyway, your info is a good starting point. Thank you so much. :biggthumpup:

 

[masterblaster]

yea,I can backup the fact Scotts boat hits hard,very linear all the way through kinda power,He ported that pup himself too,nice job bud.And thanks for the ride considering I was skiless that day.

 

[yamaslut]

Those are small threads. Do you hang over the headpipe with a monocle, Nick? :biggrin:

I can see up close good, it's just anything past 8ft that's a blurrrrrrrrr....

 

[sjetrider]

we have all tested MOD vrs. Limmitted chamber and imediateley carried all of out limmitted chambers to local weld shop and had them cut down into MOD chambers. The MOD deffinateley gate more bottom end on 3 different motor set ups. 81mm 61x ported, 61x 84mm ported and 62t 760 ported. Not sure about top end, we really didnt care wich was best there but bottom and mid were better w/ MOD chamber. Well worth the $50.00 conversion.

 

[Frosty]

Andy... shut the bottom screw and open the top till 7 threads are showing....

Hey Nick, would that be 7 threads showing above the nut, or without the nut on the screw?

 

[yamaslut]

Hey Nick, would that be 7 threads showing above the nut, or without the nut on the screw?

w/ the nut

 

[Frosty]

w/ the nut

cool. thanks bro.

 

[Idok]

Not too threadjack here, but... how much timing advance can you safely go with this setup or should I not even bother? And what implications for reliability and longevity are there with doing so?

2001 Superjet -
OEM 701 cylinder - Magoo freeride ported
Factory "B" mod pipe
ADA head w/35cc domes ~175-180 psi
stock flywheel (for now)
stock ignition
Pro-Tec modified CDI - adjustable rev limiter
stock 38's (for now - going to put on a set of 44's this fall)
dual cooling
13/17 solas with 3mm cutback
bore reduction nozzle

thanks for the info...

2-3mm COUNTERclockwise.....its going to be a subjective amount, so play it safe...

btw......the static advance is the mod that brought it all together on my squarenose......felt like a 20hp increase!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[FL-cracker]

I am running the Blaster limited pipe in my B1 can I cut a 1.5" out of the middle of that just like the limited SJ. I know when I do that I will have to cut down the pipe that loops around back toward the water box also right? Or is this mod only for a SJ limited pipe?

 

[Frosty]

2-3mm COUNTERclockwise.....its going to be a subjective amount, so play it safe...

btw......the static advance is the mod that brought it all together on my squarenose......felt like a 20hp increase!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Really? That's awesome!!! I will have to make some adjustments for sure. thanks Idok!!

 

[Sanford]

I am running the Blaster limited pipe in my B1 can I cut a 1.5" out of the middle of that just like the limited SJ. I know when I do that I will have to cut down the pipe that loops around back toward the water box also right? Or is this mod only for a SJ limited pipe?

This whole topic is based on the SuperJet chambers. The Blaster limited & mod chambers are completely different! While you can shorten a limited Blaster chamber, the outcome will be different then how it works with these SJ chambers.

 

[FL-cracker]

^^^^Thats what I thought, but both the pipes look real close to being the same, I guess it could work, I dont think I will be the first to try though.

 

[cambo au]

alright i am throwing a spanner in the works has any one checked the difference oi a superjet between the limited chamber then put a blaster chamber on just wondering

 

[Matt_E]

Yup. This topic has been discussed before. Just search, and you should find something.

 

[T-bone]

alright i am throwing a spanner in the works has any one checked the difference oi a superjet between the limited chamber then put a blaster chamber on just wondering

i wouldnt see the reason for a blaster limited pipe on an SJ, but im putting a blaster mod pipe on a sj im working on now and you better have a big wooden mallet.

 

[douglee25]

i wouldnt see the reason for a blaster limited pipe on an SJ, but im putting a blaster mod pipe on a sj im working on now and you better have a big wooden mallet.

That looks really good T-bone. I like the turf in the engine compartment. Clean looking.

Doug

 

[cambo au]

t bone what made you put the blaster chamber on what differenc is it to the superjet

 

[WAB]

Well, I found out why I had no bottom end.
My battery seemed to stop taking a charge. So I opened the wiring box, it looked ok, not perfect, but ok. So I moved on to pull the flywheel and check out the stator. The 2 screws that hold the stator to the case had loosened up and were allowing the stator to rotate with the flywheel into the timing 'retard' zone. Set it back to 3mm advanced, closed the bottom & mid water screws on my B-pipe and opened the top one about 1 1/4 turns.

Took it out yesterday to test and Whoo Hooo, My BRRRRAAAAAPPPP is BACK! :biggthumpup: :Banane01: :woot:

 

[douglee25]

Well, I found out why I had no bottom end.
My battery seemed to stop taking a charge. So I opened the wiring box, it looked ok, not perfect, but ok. So I moved on to pull the flywheel and check out the stator. The 2 screws that hold the stator to the case had loosened up and were allowing the stator to rotate with the flywheel into the timing 'retard' zone. Set it back to 3mm advanced, closed the bottom & mid water screws on my B-pipe and opened the top one about 1 1/4 turns.

Took it out yesterday to test and Whoo Hooo, My BRRRRAAAAAPPPP is BACK! :biggthumpup: :Banane01: :woot:

Glad to hear all is well. Did you remove the engine to pull the stator out? I'm debating if I need to remove the engine or not to pull the stator.

Doug