Super Jet How to make a square 650 hit hard?

[MADMAT]

I have ridden a 650 that hit pretty good and was able to handle Lake Erie waves...but I never asked the guy what was in it. Will a B pipe and a 13/16-3 prop make it pop a little better? 185psi?

One of the new guys around here just bought one but it needs some more ooomph!

 

[Matt_E]

Impeller, pipe, compression. The stock exhaust ports are tiny and can really benefit from even minimal porting. But at that point you might as well bolt on a 61X top end

 

[BruceSki]

I have a set of dual carbs for cheap if he wants to go that route.

80 shipped

comes with aftermarket manifold and reeds. Came off a ported pro-tec 650.

 

[MADMAT]

I sent him a link to this thread. I think a set of used 61x cylinders and some used pistons would be the way to go...and a prop!

 

[oxnard111]

I have a set of 650 cases that have been bored to accept a 701 cylinder.

http://www.x-h2o.com/threads/90296-6M6-Cases-bored-for-701-cylinder

 

[BruceSki]

Ooh ooh I've got it. How to make a 650 hit hard?

Drop it from really high up?

Lol j/k. They will go okay with the right parts and some porting.

 

[NVJAY775]

My sons hits pretty hard. 155 psi @ 5,000' limited b pipe, enhancer, hooker 9/15. Plate to plates rolls on a BG2 with it off his own wake. Carrying some speed though lmao!

 

[crazy4sand]

mine hits hard stock motor full coffman pipe pumpstuffer and good prop thats it. beats stock 750 sxis

 

[jd91t]

After every bolt on. And a nice low pitch prop.
I say gaskets, rings, and a niiice port job if the compression is good.
My buddy has a single carb 650 that surprises everyone that squeezes the trigger.
Pro-tec pipe, porting, cdi mod, lightened stock fw,and a 9/17.
slightly stronger than my fully bolt on'd 61x

 

[suva]

Porting, along with all the other mods. My old 650 has better bottom/mid than by brother's limited 701 and is only about 2mph slower topped out.

 

[GIL]

I saw a 650 hit hard once-it fell out of the bed of a truck going down the interstate at about 80mph!!! LMAO

 

[swapmeet]

I bought a 650 SN for my wife that raises a lot of eyebrows.

Coffman head (says 180psi, never measured it) Coffman pipe, and I'm assuming a low pitched prop. Runs and rides great, I'm scared to jack with it cause it seems like such a well put together ski. All it needs IMO is a shorter pole, and I just put a RN pole on it.

 

[mthomps]

I'm the new guy madmat's talking about!

Right now the first thing I wanna do is get a prop. Either a 13/16 or a 9/15. I've gotten multiple responses and those are usually the two that come up. .

So many options...I gotta make a plan though because I need to save for the right stuff.

I love my 650 though...but after riding madmats beast all you want is more more MORE!

Did my first sub yesterday! I LOVE this sport.

 

[djraider700]

I'm the new guy madmat's talking about!

Right now the first thing I wanna do is get a prop. Either a 13/16 or a 9/15. I've gotten multiple responses and those are usually the two that come up. .

So many options...I gotta make a plan though because I need to save for the right stuff.

I love my 650 though...but after riding madmats beast all you want is more more MORE!

Did my first sub yesterday! I LOVE this sport.

Congrats on the sub! That's what it's all about. Having fun. Ride what ya got and upgrade as you go!

 

[mthomps]

I ain't trying anymore subs 'till I get an oem flame arrestor though. Seller has the K&N crap on it. I've gotta do the hood mod this winter too. I'm researching that and reinforcing the hull. I want a surf ready boat for big lake erie days.

I've been looking around ebay for driveline parts. It looks like I can get a complete 62t, 38mm carbs, and a protech pipe for less than $1,100. Should be a decent driveline right? If I can swing it when the time comes to pull the trigger I'll go with the factory pipe though.

Prop before motor?

Hopefully I'll have that set up by next August. I don't wanna pipe the 650 because I don't feel like messing with the exhaust manifolds after I get the 701.

So yeah, I'm stoked on riding. 650 sn kicks the hell out of my 300sx I rode last year. I've been going out 3 or 4 times a week since I got it.

The pistons are well worn pretty good. Carbs are a tad rich but I don't wanna mess with it and half to waste cash rebuilding a 650 that will be on the shelf next year.

So far so good! Had a stuck bendix earlier in the week but caught it on the trailer. Starts upon button push in water every time. Lovin' the SJ!:Banane25:

 

[SXIPro]

I'd go Hooker 9/15. That way as you upgrade to a 701 or modded 701 you won't have to re-prop.

 

[mthomps]

You think the 650 will spin that prop alright if I get it before driveline upgrades?

 

[kevbo]

You think the 650 will spin that prop alright if I get it before driveline upgrades?

Yes, the 650 has as much trapped volume as a 701 because of its lower exhaust port. Its off idle response is about as good, just runs out of power sooner. This is why the same low pitched impeller will work for 650-760 engines. The 650 will run out in the low 6000s where as a 760 may hit 7000. A lighter load would not do a 650 much good without also raising the ports for more rpm.

 

[js/sj]

Transfers are at a different angle too compared to the mismatched 61X cylinders