No power up top?

[screaminta]

I just put a CR head gasket and a 38mm A/S carb on my 86 R. the bike runs like a raped ape down low now, except that it seems that I dont have much more top end power? If I am just crusing at like 1/2-3/4 throttle and then nail it full throttle, it doesnt seem like it pulls much more if any at all. I am running a 52 pilot at 1~1.5 turns (it was cold out) DDJ needle on the middle clip, and a 175 jet. I had a 170 in it initially, then up to a 175 but not really any change. Any thoughts?

[707trx250r]

you should do plug chops and check your jetting. I would say though your main is rich if it doesn't pull up top.
later
Adam

[kiesta00]

yeah 175 sounds rich for a fairly stock bike...i have a 165 main in my bike with a top end pipe, airbox eliminator filter, and 165psi compression.

[screaminta]

I figured that it was gonna be ok with the 170 at first, and then at least change with the 175 but no difference. My setup is a Paul Turner race pipe, airstriker carb, open airbox, vforce reeds, cr gasket, stock porting, and 2nd overbore(66.5mm). My compression is right at 190, but she seems to be fine with mobil 93 octane and amsoil dominator at 40:1. Any other thoughts, I'll have a chance to do some plug chops this weekend coming up, you all think that i should go to a 165? thanks in advance.

[86 Quad R]

plug chops will tell ya exactly what size main jet the engine wants/needs.

what we think doesnt matter. except if ya were trying to get a baseline :cool:

[C-LEIGH RACING]

No power up top,,,,do you know what porting is in the cylinder & what pipe your running, that will make the greatest difference where the engine runs best.
Neil

[screaminta]

I stated earlier that the porting is stock, and I have a paul turner race pipe. It is real strong in the midrange, but it doesnt seem to get any faster from 3/4-full throttle?

[deathman53]

is the pipe a type 6 or hi-rev. A type 6 will quit making power after mid range, a hi-rev will scream at mid-top, but little at bottom end.

[screaminta]

There is a label on the pipe that says it is an "89 trx race" pipe. thats all it says.

[kiesta00]

what kind of "top end" are you comparing this to? A fixed up 250r or are you just expecting more performance for the mods you put on? Try a 165 main and see what that does.

[C-LEIGH RACING]

I surly missed that reply, but with stock factory porting, your getting just about as much top end as the porting will support.
Most stock R cylinders come with an 88 or higher degree opening time on the exhaust port, thats what controls how high the engine will rev & pull out.
Jetting will make a difference to an extent the leaner you go.
Neil

[707trx250r]

When I had my paul turner pipe and stock cylinder It didn't have much top end. Just gobs of mid range pull. When I went to the sparks tt it helped a lot. Now with the 350pv it pulls like a crazed ape all over. Any way I would do plug chops and maybe go leaner. I had the same set up and it was darn fast.
later
Adam