200X wiseco 10.25:1 Vs 12:1 piston - opinions

[oscarmayer]

If your running a higher compression piston, your jetting will be different.


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[350for350]

Anything you do to give it more power will require rejetting. How much bigger depends on what you do to it.

[Leevvii]

Heres what i have, i dont want maximum performance, but a little more zing would be nice. Also, looking to maybe do more to it in the future, hence i thought the 12:1 piston might be the best choice for now, even if it is "underperforming" a bit at present, if you follow me? So, any advice on jetting the KEIHIN to suit the 12:1 wiseco, or am i just wasting time with this. Any advice welcomed, i wont hold you to it! LOL

My plan is :-

66.00mm bore, wiseco 12:1 piston, but 10.25:1 remains an option

Head is ported [non factory, by previous owner],

Standard 200X camshaft.

I will purchase DG pipe in near future [most likely DG RCM - #04-2108 ],

Running 98 oct fuel.

24 mm carb [with unifilter]. I have 2 carby's to choose from..

1 x Standard 200X - KEIHIN PD-62B/AVI
FUEL JET: 125
PILOT (SLOW) JET: 40
JET HOLDER: No markings
AIR SCREW: Standard-No markings
FLOAT VALVE and SEAT: seat marked 20
THROTTLE SLIDE:

OR

1x MIKUNI Carburetor Carb M CA06 [EBay .........wot!??LOL allegedly for a 200X '84, ...but seems massively under-jetted to me??]
FUEL JETS: 95
JET HOLDER: No markings
PILOT (SLOW) JET:- 15

Drive gearing :- 13 - 44 teeth.

[Leevvii]

Seems the jetting in the Keihin is non standard on mine.

[yaegerb]

Use the 1st carb. The 40 pilot and 125 main should be a good starting point.

And get a more agressive cam to better suit the 10.25 or 12:1

[Leevvii]

The 40 pilot and 125 main should be a good starting point.

For the 12:1 piston, .....yes?
Think i will wait for the agro cam, curious, are they available readily?

[yaegerb]

Should be ok for 12:1. Full disclaimer though. I never could get my 218 running right on a stock VM 24. But it was a pretty wild little motor. I had to step up to a 28mm mikuni that had some specific tuning done to the carb and I ran a custom air intake.

Never heard of agro, sorry. I suggest mega cycle or web.

[Leevvii]

Should be ok for 12:1. Full disclaimer though.

Thanks for the advice, i'll' send you a postal bomb if it dont work! .............joking, of course, i hope that comment does not trigger the NSA terrorist alert criteria, we live in strange time dont we!

agro cam = aggressive camshaft. Are they available readily to buy or is custom machining required on my current cam?

[Leevvii]

I restored the carby by using the boiling water and vinegar method, ......freakin big difference.
BEFORE:-
AFTER:-

[yaegerb]

Thanks for the advice, i'll' send you a postal bomb if it dont work! .............joking, of course, i hope that comment does not trigger the NSA terrorist alert criteria, we live in strange time dont we!

agro cam = aggressive camshaft. Are they available readily to buy or is custom machining required on my current cam?

Ready to buy, look on webcamshafts website.

[Leevvii]

thanks, that good info, cheers.

[RubberSalt]

If it was me, I'd follow Mickey Dunlops suggestion on the build.

e85 has a shelf life of about 90 days in a nice contained environment. with it containing so much alcohol, it's more prone to absorbing moisture in the air. Depending on were you live, I'd say 2-4 weeks it need's to be drained out.

I love e85, but for just running through the bush, I'd stick to strictly pump gas. It's a proven fuel that is readily available. You also don't want to run e85 with out increasing the jetting. It requires 30% more fuel than premium, and if you don't rejet, you'll over heat pretty bad.

[DohcBikes]

E85 is trash. If you need more octane, buy race fuel.

In order to properly advise jetting and octane requirements, altitude and your regional method of calculating octane (yes there are multiple formulas-RON MON and AKI) will help get you closer. 98 octane RON is plenty to run 12:1, but 98 MON is generally not. I believe your ratings are AKI, which is somewhere in the middle. Keep an eye on cylinder temps through the jetting process, run it as rich as you can without fouling plugs or bogging, and you'll be fine.

[oldskool83]

90 days....had crap go bad in 2 weeks. Buy fuel mix it or put somthing in it a day before you go ride, then ride and drain your carb bowl. Being doing that for years...never have carb issues again.

[Leevvii]

Australia is RON from what i can tell.