went to dunes!

[LONG-ROD]

I just took my R that I just finshed to the dunes, I have a 39 pwk, duncan raceing did the top end and port have 19 cc dome run 110, and I have the pyrmid reeds, and a Bill's pipe, ran 8 paddle extreams. I was quit dissapointed in it. I was wanting to know how much better a 350 motor would be.

[All250R]

More than likely you don't need a 350, but need to finish configuring your engine. Throwing dispalcement on a bottom end is often a low tech way to fix problems with the smaller setup.

I've never seen duncan's porting, but unless it's hacked, focus on the pipe and head setup first. Duncan doesn't sell Bill's pipe, so maybe it's not matched very well. Check compression. Make sure there are no air leaks too, if you have a leakdown tester.

[mcboomport]

What gear ratio were you running? Where in the powerband were you dissapointed in the bike?

[LONG-ROD]

The lower end is fine I just rebuilt it and there are no air leaks. I have right at 200 lbs. compression and I run 3 gallons of 110 an 2 gallons of pump. I know my pipe sucks, does it make a huge diffrence. Stock 250 r where keeping up, maybe I am to rich, I like to play the safe card. my main jet was 178 out there DGH on the 4th and 55 piolet.

[LONG-ROD]

Oh and I am running 13/39 for gearing.

[312R1]

What porting did Loren do? midrange? Your combo sounds good other then the pipe. Is it a stock cylinder or a PC2000?

I have a stock cylinder that Loren ported for me and it screams. I'm running everything the same as you but the pipe, silencer and gearing. I have a Pual Turner (race) pipe, fat boy silencer and my gearing is 15/38.

I'm running my 275cc PC2000 right now and my jetting is 55 pilot 4th clip on the needle and a 182 main. So if your running a stock jug your jetting sounds a little rich to me. Do some plug checks.

-Steve

[All250R]

Originally posted by LONG-ROD
The lower end is fine I just rebuilt it and there are no air leaks. I have right at 200 lbs. compression and I run 3 gallons of 110 an 2 gallons of pump. I know my pipe sucks, does it make a huge diffrence. Stock 250 r where keeping up, maybe I am to rich, I like to play the safe card. my main jet was 178 out there DGH on the 4th and 55 piolet.
In a short amount of words, the pipe on a 2stroke is as much a part of the engine as anyything else you can think of. It's not like a 4stroke as you know where you're mostly just trying to evacuate gas with a certain amount of backpressure. 2stroke pipes are likely where most of the innovation in these small 2stroke engines have come from in the last 20 years or so. Jetting will fine tune an engine, but if you're having trouble leaving stock R's in the dust you've got bigger issues than jetting to worry about first. Your jetting numbers aren't far off enough to cause that kind of performance lag is my guess.

There are a lot of small things you can do, like intake matching, reeds, port cleanup, squish adjustment, that added up make a good difference, but pipe and porting combination need to be in synergy or you're probably just bandaiding over where the real work needs to happen (provided the engine is sound). The pipe is what sets the blueprint for what the motor is supposed to run like because it dictates evacuation, scavenging srtength and timing and return pulse stuffing. Porting's best hope is to take advantage of strengths of the pipe design. So everything else should fall in line behind that. So, yes the pipe is a good chunk of the engine to think about when you're concerned about how it runs.

[LONG-ROD]

Well I talked to loren and asked him agin exactywhat kind of port he did and this is what I got. He said that they did not match port the sleeve when who ever put the 310 sleeve in it, so he bored the sleeve and did there 3 stage hone, then ported the cylinder back to stock size, so really I have no port work. That and a 19cc dome piston and gasket cost me $600. I feel a little slided!! So my question is will I gain a lot sending a diffrent stock cylinder to him and haveing like the national port job and a paul turner pipe, or will it be worth the $1000.00. My friend bought a 250r last night with some work and a curtis sparks pipe, and wow did it sound good and would wheelie shifting in to third with very little effort on my part, my won't do that.

[Aceman]

Hmmm, I have a Pro-X 310 cylinder with cast ports and it seems to pull pretty good. Never rode another R though, so I can't compare.

Just an idea, but maybe a few pulls on a dyno to get the jetting dialed in might help. It'll let you know if it's putting down the HP it should be also. I'd probably try that before I sent that cylinder back to Loren for another 1000 bucks worth of work.

[LONG-ROD]

Ya but either way a ported R will be a big diffrence over my stock ported R, Right? If not I won't toss my money away.

[gojk]

Send the top end to Neil at C-leigh racing. He will set it up just how you want it. Tell him where your like the power and how you ride and I am sure you will be impressed when you get it back.

[LONG-ROD]

I want my bike to pull a wheelie with me standing on the pegs in 3rd gear with little effort, Ideal I would like to do somthing with the gearing to be moveing alittle faster thaen 3rd but not as fst as 4th and be able to pull it up in the mid so I can ride it for a good while. Now I have to pull it up in 2nd and shift it to 3rd and it's just a bit to slow in 3rd to keep up with the others and forth only pulled when I was all over the pipe, and 5th almost made it to the top and we wont even talk about 6th so any gearing sugestions would be great.