SXR Big Pin 750 in SXR

[naithgroves]

Bit of a budget build really, but just working with what I have before maybe buying a Krash Industries jb1 hull.
http://www.krashindustries.com/

I picked up a mates 2008 SXR hull pretty cheap to swap all my gear into.
Basically I have a big pin 750 with group k head and lightened fly wheel. It has a 46 sbn with r+d intake manifold, factory exhaust manifold and a coffmans exhaust, Jss coil and the exhaust ports look like the have been machined? They are polished in appearance.

Also The water box has the 5 hole mod.

The pump will have a hooker 10/16 prop.

How do you think this combo will go? Is there anything you can suggest I do to make this better, lighter etc?


Much appreciate any help.

 

[N3vrSat1sfied]

I ran a 8/16 swirl big hub with a similar motor, with a Factory b pipe. (which was the best mod i did! I had the coffmans exhaust before the b pipe)

If you got the stuff why not switch it, should run fine, and i think everything will switch right over.

 

[naithgroves]

How was the 8/16, Is that a little bit more suited to the 750 motor with mods?
I do have the stock exhaust for the sxr but not entirely sure if the coffmans will be any better?

I'm looking at cutting the liner out of the hood and also an aluminium bed plate just to save a few kgs.

Has anyone got some photos of a hood chop?

 

[N3vrSat1sfied]

the 8/16 worked really well with the 750 motor, Good hook up both flat water and surf. Im sure the coffmans is better than stock. But if there is only one thing i could recommend it would be sell the coffmans (run it first so you can compare) and buy a b pipe. YOU WILL BE HAPPY YOU DID, like i said it was the biggest improvement i made on that ski.

 

[naithgroves]

Some photos of oem parts swapped for some aluminum and the coffmans vs oem exhausts

 

[djkorn1]

If you can, get an sxr cylinder and top end. The 750's are dogs on the bottom...the 8/16 may help, but I'd put the money into a cylinder.

 

[Big Kahuna]

keep in mind the SXR hull is alot heavier than a 750 hull. The 800 motor was designed with more bottom end to help get this hull up and moving.
Do what DJ said, find an 800 cylinder.

 

[naithgroves]

I would love an 800 cylinder but they are pretty hard to come by here. I might just have to prop it Lower then? Dropped 8 kgs of the ski so far. I'm worried about the bottom end now!

 

[naithgroves]

BANG! Got some SXR jugs and a head comin. Il see how the 750 goes to start with then once I get the factory wet pipe il cut some bore out and put a couple nice slugs in for an upgrade. Just have to order a hooker 10/16 prop and powder coat a few parts. All comin together

 

[djkorn1]

10/16 is too low. It will spin out with that SXR cylinder. Just get a stock SXR Solas Swirl prop. They are cheap on SBT's site.

 

[naithgroves]

Thanks DJ. I have just thrown my oem SXR prop in the pump for the while. It's definitely heavier than the am props for sure. Il be runnin the 750 for a short time before building the 800 so it may be a bit of a slug outa the hole....

 

[naithgroves]

Heres some footage of it running.

http://youtu.be/DcYGdMjY328