Brad Clarke

I purchased a 96 Zxi 110 to put the engine into a SXR. When I stripped the 1100 engine I found out it was a 900!!.(in a 1100 hull) I have purcahsed a 1100 Cylinder & Head, ported cases to match & fit the pistons, I dont know if the electrics are 900 or 1100 - can you tell me the differance, timming curves etc.

Group K

You may have more issues ahead of you than just electrics (that said, the ignition should work fine on the 900 lower end setup).

The 900 and 1100 have different strokes and different wrist-pin diameters (900 is 73x71....1100 is 80x74). Back in the day, we did a few big bore conversions of 900s. The 1100 cylinder bolts up, but it has a deck height that is much too tall. The cylinder requires very significant decking on both top & bottom surfaces to have the right deck height. In addition, you'll need to use the early style "small pin" 750 pistons to fit up to the 900 rods. The 1100 head will have too big a volume (even heavily milled) so you will need to modify the 900 head, or get a very high compression 1100 aftermarket head.

All that said, the 900 with 81mm pistons is 1097cc, and can run very strong. The 1100 cylinder can accept pistons up to about 83mm.

Hope that helps.

Respectfully, Harry Klemm

__________________
Unless otherwise stated, responses to all forum posts are based on my personal experiences working within the PWC industry, and developing high performance PWCs since 1987.

www.groupk.com

Brad Clarke

Hi Harry, As posted I have this engine running now (and well) in SXR hull, running 63.5mph @ 7700rpm very strong acceleration. I want more !!
Currentley running stock engine with SXR Mikuni Carbs/Prok filters, 140 psi, 40 thou sqiush, stock exhaust with water mods, Dual cooling,81mm pistons, advance plate, stock waterbox, gutted, stock pump with TBM cone, 80mm Exit nozzle Skat 14-19 (pitched up)
I am thinking of raising comp to 160psi, porting the cases, running exhaust straight out the back, Mild porting on cylinder (what would you recomend for this, raise exhaust, widden?)

Thanks in advance

Brad Clarke

Group K

Brad,
Glad to see your project is working well. You are correct that increasing the compression,and exhaust exit will both help considerably. The 1100 cylinders carry some pretty good port timing, so the gains from porting or case porting will be noticable... but not huge (the cylinder porting will get you the bigger gain).

All that said, you are spinning "way" too many rpms. The 1100 port layout and exhaust work best with a peak of about 7300 (in the STX1100 three seater hull). For your SXR hull, I would strongly consider propping to a 7100- 7200 peak (especially with the higher compression). If you keep spinning the rpms you have, the engine will be delivering a broken rod before long.

Respectfully, Harry Klemm

__________________
Unless otherwise stated, responses to all forum posts are based on my personal experiences working within the PWC industry, and developing high performance PWCs since 1987.

www.groupk.com

Brad Clarke

Thank-you

Brad

milaman123

since i've been tunning my 1100, i have read alot of good stuff writin by you. this is more good stuff thanks again!!

Brad Clarke

Hi Harry,

I am wanting to get my cylinder ported for my 1100 - are you able to do this if I send it to you, and at what cost. I want a 80-85% job

Regards,

Brad

Limitedski

Not to but in but what do you mean by "I want a 80-85% job"?

lakester

hey brad

how did you know you had the 900 engine??

I think I may have the same problem because my 1100 is no faster than my friends zxi 900

Brad Clarke

I removed the head to inspect the condition & found smaller pistons !!