X-Flow piston wash

[wanagofass]

Ive raised the compression and started jetting a 2.5L v6 crossflow and am a little concerned with leaning it to much due to the way the deflector is directly in front of the intake charge. Can anybody give me any tips on jetting/reading the pistons on these or have any pictures of one jetted right?

[terry taylor]

Ive raised the compression and started jetting a 2.5L v6 crossflow and am a little concerned with leaning it to much due to the way the deflector is directly in front of the intake charge. Can anybody give me any tips on jetting/reading the pistons on these or have any pictures of one jetted right?------------------------What is your compression now psi? Simply start with the stock carb. jets,this might be all that's required.

you may not

[wanagofass]

Compression is right at 120. It's got stock carbs and jets now and looks rich, what i'm not sure of is how large of an area should be washed off at the intake ports compared to a looper. It seems to me that a crossflow tuned close would always look richer than a looper because of the deflector in front of the intake ports.

[terry taylor]

I don,t know about[ washed], cross flows run rich and the plugs should be dark brown and possibly a little wet.91 octane and a synthetic oil will keep it clean and healthy thanks.

[Forkin' Crazy]

I always put too large a jet in my xflow and worked my way down. After it stopped 4 stroking I called it good. A tad bit rich on these motors won't hurt a thing.

[6Killer]

What was your starting compression numbers and what are they now?

[wanagofass]

This motor had the bath tub heads(#136-137s) @ ~85psi. It's now ~120psi

[FoFittyFoSS]

I always put too large a jet in my xflow and worked my way down. After it stopped 4 stroking I called it good. A tad bit rich on these motors won't hurt a thing.

Sorry to ask a dumb question but what do you mean by "4 stroking"? I have an old xflow I may want to tinker with but not sure which heads I have. My compression is about 95# right now. Thanks, Scott

[south599]

sound like you have the stock gt heads. i just bumped mine up to those to get that. to get any more you have two options. find a late 70's model 200 heads or get yours shaved.

[groundloop]

Sorry to ask a dumb question but what do you mean by "4 stroking"?

The engine is running so rich that it doesn't fire on every revolution.

[6Killer]

If it were mine, I would go up 3 sizes. 56 to 62 etc.

[Forkin' Crazy]

The engine is running so rich that it doesn't fire on every revolution.

That and at least on mine, you could back off the throttle a bit from WFO and it would actually pick up RPMs.

[FoFittyFoSS]

The engine is running so rich that it doesn't fire on every revolution.
Thanks for clearing that up. I have a 1990 Evinrude 150XP Crossflow. The part # on my heads is #333545 as best I can tell. Would I benefit from a head swap? Sorry if I am highjacking the OPs thread.

[south599]

unless im incorrect you would have to get your heads cut. the late 70's model 200 heads were the highest stock compression, but not much higher than the gt/xp. cutting em is the only way to increase it.

[Forkin' Crazy]

unless im incorrect you would have to get your heads cut. the late 70's model 200 heads were the highest stock compression, but not much higher than the gt/xp. cutting em is the only way to increase it.

I have two sets, one is an early 200 and the other a small bore 235. I think the early 200's were the tightest. And they were tighter than the GT/XP. I have all three sets. :) The early small bore sets I have are going to be machined to go on a big bore motor. Av gas only. ;)

[baja200merk]

The early small bore sets I have are going to be machined to go on a big bore motor. Av gas only. ;)

:eek: :leaving: