"Limited" engine setup

[Vortex]

Just looking for some advice on what parts to try on my 701 rebuild. I have a fresh 82mm 61x cyl with no porting, mod chamber b pipe, ocd cdi/coil, 215 psi @82mm ada head, and older novi 48s with a dasa intake and vf2 reeds.

Are the larger carbs and higher compression worth trying without a ported case/cyl?

Mainly doing closed course style riding in lakes and surf. Currently running a 9/15 hooker but I am open to try something different

 

[Vumad]

The compression question is budget related. Can you afford to pay $10/ga for premix. Things like carbs cost the purchase price - sale price / time used. Race gas can easily raise the operating costs by $4-8 per 10-20 mins of race time, no sale costs to recover. My limited superjet with stock carbs burns like 1ga/10-20 mins racing. That means a day of practice is about $25 vs race mix at about $80. The carbs themselves are awhole different question but bigger carbs means less mpg.

 

[user_error]

if you are building a true limited spec sj to be competitive you will need/want a 760 cylinder with girdled head, r&d dry pipe, and the intake setup you have, plus an enhancer.

there is basically no point in burning race gas with the setup you listed unless you just want to waste money.

with the parts you have i would just get lower compression domes.

 

[Quinc]

Shouldn't need a girdle kit on 62t or 64x cylinders.

 

[Vortex]

if you are building a true limited spec sj to be competitive you will need/want a 760 cylinder with girdled head, r&d dry pipe, and the intake setup you have, plus an enhancer.

there is basically no point in burning race gas with the setup you listed unless you just want to waste money.

with the parts you have i would just get lower compression domes.

Not really trying to be super competitive just have a fast and reliable ski that I could take to a few races. Would like to try a 760 cylinder someday.

I know all about the cost of race gas I ran the 215 psi head last year on a ported 718.

I'll probably just build this engine to stock spec.

 

[lanmine657]

No reason to have that much compression on a limited other than wasting money on fuel as others have said, no reason for the novi's either, get some stock 44's, your 9/15 is good. spend your money on handling, tubbies, mag pump, intake, ride plate, pole, stearing and bars. Easiest and cheapest way to build a race ski is at the gym and practice

 

[Vortex]

No reason to have that much compression on a limited other than wasting money on fuel as others have said, no reason for the novi's either, get some stock 44's, your 9/15 is good. spend your money on handling, tubbies, mag pump, intake, ride plate, pole, stearing and bars. Easiest and cheapest way to build a race ski is at the gym and practice

True. Conditioning is key. I should do more there. I have been practicing with a race team for the last few years though, and that has helped tremendously.

 

[Vortex]

if you are building a true limited spec sj to be competitive you will need/want a 760 cylinder with girdled head, r&d dry pipe, and the intake setup you have, plus an enhancer.

there is basically no point in burning race gas with the setup you listed unless you just want to waste money.

with the parts you have i would just get lower compression domes.

I just liked running the race fuel, the way the power hit and the smell of it but I think you are right. Probably should run 35 cc

I also have an atp epic, but its um..."finicky " lol.

So would you think I could get 55mph out of the ski with 185psi 61x cyl and the novi setup

 

[eastcoastjumper]

I just liked running the race fuel, the way the power hit and the smell of it but I think you are right. Probably should run 35 cc

I also have an atp epic, but its um..."finicky " lol.

So would you think I could get 55mph out of the ski with 185psi 61x cyl and the novi setup

using a 9/15 hooker?

 

[lanmine657]

I have 9/15 on my limited, 61x/62t but have a speedwerx dry pipe, 183psi, 51/52mph @ 5000ft so at sea level yes you should get mid 50's with a 9/15

 

[bored&stroked]

Dual 48's on a 701? Wow that's alot of carb for such a small motor. And forget race gas, mix avgas at only $4/gallon and enjoy.