200x ????

[Erics350x]

Ok, im working on building my 85 200x engine and have a few questions.
I've got two piston laying aroung to choose from 12:1 or 11:1 wiseco's? The 12:1 i already have a cylinder bored for. What fuel and jetting would you recommed?
Is there any way to loosen the cam chain tension without removing the flywheel? It's been atleast 15 years since i tore into a 200x (building this for my son). What are the odds of a light weight kicking this thing over with either piston?

[bad350]

i would go with the 11 to 1 so you can run pump gas the timing chain adjuster is on the top of the case on the bottom end

[SWIGIN]

they never made a 11 to 1 unless you turned a 12 to 1 down

id go with the 10.25-10.5 to 1

[Erics350x]

looks like i was wrong about the pistons, one is a 12:1 wiseco and the other im not sure about? It's a flat top and has 965 on top and on onside has L 446 wrist pin then P 2 the other side says honda?

[Erics350x]

After further research it looks like i got screwwed when buying this piston, it was listed on ebay as a 12:1 wiseco 1mm over and it apears to be a oem stuck in a honda box. I hate ebay!

[Dirtcrasher]

I'd shy away from high compression pistons on the 85 and under 200X because of the kicker problems. Unless, people have found ways to resolve those issues......

My 86 12:1 does not run it's best without race gas....

[Erics350x]

Doesn't the stock compression piston have a dished top? What compression has the flat top?

[bad350]

i think the flat top is 10.25 to 1 but not positive

[Erics350x]

Did honda offer a 10.25:1 piston?

[SWIGIN]

i think the flat top is 10.25 to 1 but not positive

185-200 had a dished top and were 8.something to 1 (8.25 or so)

200x was a flat top stock and was 9.something to 1.... 9.5 to 1 tops (dont feel like looking it up....lol)

a 10.25 will be raised maybe 1/4 or less and a 12 to 1 will be a 3/8 or so

[Erics350x]

Thanks Swigin

[The Goat]

also...anyone can kick off a 200x. no matter what the compression.

with a grunt, you could probably smack the kicker with your hand and start it.

[SWIGIN]

also...anyone can kick off a 200x. no matter what the compression.

with a grunt, you could probably smack the kicker with your hand and start it.

they arnt that easy to kick with a tight 12-1 but i hear you.....but you know 90% have striped kickers it seems so you might be right...lol

[Texas 200x]

I just put a 10.25:1 Wiseco in my 200x The top is domed. The stock one was flat.

[Texas 200x]

What did you end up putting in anyway?

[Erics350x]

12:1 Wiseco But, I haven't gotten a it started yet because i couldn't find any race gas this weekend.

[The Goat]

they arnt that easy to kick with a tight 12-1 but i hear you.....but you know 90% have striped kickers it seems so you might be right...lol

I hear ya. You know when I put that 10.25:1 in mine...compression tested at over 195 psi...it was somewhere between 190 and 205...the gauge from autozone had a ton of moisture inside the lense.

I found that the 200x kicks over a lot like a 2 stroke...don't kick it hard...kick it fast, and it's all over with.

so what's the minimum octane you can run on a 12:1

[SWIGIN]

in 86 when i got my 85 200x it had a 12:1 in it and a kerker pipe other then that it was stock and it would ping once or twice a summer running on 110 oct CAM2.

so id say 110 oct is as low as i would go, my 200x was ''new'' and it seemed to make a LOT of heat for a little motor.

[Erics350x]

It said 102 or better race fuel on Wiseco's site. Can't you get 102 at the pump?

[SWIGIN]

the thing is you might get away with 102 or so but only if you have a race cam and a fully ported head.

a big cam lowers the cly presure and a high flowing head helps get the cool air in and the hot gases out.

mine was stock other the the piston and pipe and like i said it barily ran on 110

[Erics350x]

Any idea on where to start with jetting? It's stock other than the piston and air filter.

[SWIGIN]

mine was jeted stock....110 main for a few years, ran great

[Erics350x]

I test fired the engine last night and it wont rev at all with the stock jetting and pump gas.

[SWIGIN]

no, it should run like crap on pump gas

id go to 110 like i said and try that

[Texas 200x]

If you have any small airports near by you may be able to buy avgas from the FBO. Its 110 octane low lead. Its usually cheaper than racing fuel. Very few gas stations carry above 93 octane.

[Texas 200x]

Many people who run stock cars run av gas. Just don't use it in newer cars because the lead will ruin the sensors on anything with a computer in it.

[Erics350x]

Ok, i got 110 race gas in it and it still runs like crap. It rev's alittle better on half choke. It has to be jetting or the 200e cdi i put on it. I figure if it was the cdi it wouldn't idle so well though?

[Dirtcrasher]

Eric, mine ran terrible on pump gas, better on race gas but the jetting was still way off.... I was way way way lean. I threw a 145 jet in it (stock was 112) and it took off like a bat out of hell.

It was a 30MM knockoff Mikuni and Sudco couldn't guarantee me that the jets they sold would fit even if I gave them serial numbers. So, I snagged a 28MM flatslide from Garageboy and it is SO much closer that it's scary.

I still have plenty of testing and tuning to do before it's dead nuts but at least I can actually GET jets for this one........

If you are or are not running the lid, take it off or toss it back on and see if there is a difference. I wouldn't want to run a lid with that piston, thats what it's all about - I guess you have some sort of exhaust on there too??

I'll be the first to admit that it's tough to even find a baseline in terms of jetting to start with sometimes.

[The Goat]

start off with 132 in the stock carb.

with no airbox lid and an exhaust you should be within 10 or so.

enough to tell at least. it's a guess, but it isn't a bad one.

[Erics350x]

Thanks for the help. I'm running a stock pipe for now and no air box lid.

[Erics350x]

Ok i got a 132 main and it still wouldn't rev, changed the cdi back to the oem one after smacking it on the ground a few times and it runs great on the trailer. I'll pick up a new plug Today and give it a good run to see where i stand with jetting.

[Erics350x]

This thing is a pain in the butt to start, should i change the pilot jet size at all?