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Baseline jetting for 2001 CR265 mod motor

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Modded 2001motor, PWK 38mm, heavily ported for mid-top end power, squish/compression set for half pump / half race fuel. Not sure what's in there now but feels a little lean, just looking for thoughts to see if I am outta the ballpark. 60-80degF ambient, 100' ASL.

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Hey Ed

Find out what jetting is in there now & post it.  Who did the port work ?

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'sup. I am trying to avoid people saying what I have is correct! Plus my wife hates when my hands smell like gas at night! ;)

HP Bikes did the work, hpbikes.com, supposedly 53rwhp and I believe it. A little tough for me to ride compared to the Modded 450s I am used to. I think I only need to add a flywheel weight and it'll be good.

Edited by Eddie8v

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'sup. I am trying to avoid people saying what I have is correct! Plus my wife hates when my hands smell like gas at night! ;) HP Bikes did the work, hpbikes.com, supposedly 53rwhp and I believe it. A little tough for me to ride compared to the Modded 450s I am used to. I think I only need to add a flywheel weight and it'll be good.

Gotcha..

For a 265 I'd think it would put out a little more than that.   I'm running an 03 with PC mods head cut for race gas with the 00 Kehin 38mm PWK airstriker.   Not sure if it will help you but these are my current settings for 0-1000 ft., 60-90 deg. temps, 32:1 HP2 & VP C12 / 91 CA 76 - 50/50 mix sometimes.

PJ - 45

MJ - 175

slide # 7

715/289R needle

3 rd clip

AS  1 1/2 - 2 1/2 out       

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250 I'd think it would give you a ball park figure. 

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Slightly different set up but amazingly close fueling needs:

Cr295 just above sea level. 100% renegade 110 at 40:1 motul 800

Gorr ported mo better for race fuel. 235 psi compression cold. Rad valve. Fatty with shorty silencer. 38mm pwk

7 slide

Stock needle 3. 714/289r

178 main

50 pilot.

70-75 degrees.

This engine likes more fuel than any 265 I've had so I'd guess you'd be a step leaner on the main and pilot

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At 80-90deg I was running:

7 slide, 178 Main, 48 pilot, stock needle 3rd clip, 2 out on A/S. Sounds like I am not far off anyhow as a gut check...

Maybe rich on the main, not lean? Gonna be 20-25deg colder tomorrow am for sure, so I will leave it as-is: if it feels leaner, it's lean. If it runs better, it's rich.

I guess the mid feels a bit more anemic that I would have expected, maybe my PV is afu, too. I will check for proper operation, tomorrow.

Thanks guys!

Edited by Eddie8v

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I've had success with a one step leaner taper on the needle. Really wakes up te midrange but it typically forces you to use a slightly richer pilot to avoid a ping when you roll the throttle on

Cej wakes up the mid as long as you adjust for the different length

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Eddie try moving your needle to the 4th clip if you think your lean in the mid range. 25 degrees colder is going to make a pretty significant difference and if your already lean its going to get worse as you already know. What makes you suspect it's lean? Bogging? It seems with a big bore that leaner jetting is required alot of times. You should be pretty close where your at, but every bike is different. What does the plug look like? You will know pretty quickly if your to rich because it will want to load up really quickly and it will sputter when getting on the throttle.

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Feels like a flat spot in the mid-range, surely not rich. I will know asap first moto in the morning. Got a bag-o-jets in the toolbox and a needle or two if I wanna swap them out. Plug didn't show terribly rich but I rode in the woods at low-rpm a bit last ride.

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Try richer on the needle. I have a 2005 with gorrs 265 kit. Stock carb though. But it ran very lean when I went 265 with mid top porting with jet specs that worked well at 250cc... I have vforce reeds and PC pipe/silencer combo too.

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Slightly different set up but amazingly close fueling needs:

Cr295 just above sea level. 100% renegade 110 at 40:1 motul 800

Gorr ported mo better for race fuel. 235 psi compression cold. Rad valve. Fatty with shorty silencer. 38mm pwk

7 slide

Stock needle 3. 714/289r

178 main

50 pilot.

70-75 degrees.

This engine likes more fuel than any 265 I've had so I'd guess you'd be a step leaner on the main and pilot

My needle is a 715/289R, not 714... hmmm.

I cleaned the plug, then putted around the yard yesterday for a while and the plug looks pretty rich, so I am going leaner on the clip and try again tomorrow. Pilot seems ok as I get use out of the a/s, can't go out more than 2.5t before idle roughens.

Also, bike has V-Force reeds and a 3mm reed spacer.

Edited by Eddie8v

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Mines a 715. Sorry for the typo.

The midrange flat spot on my 300 was due to a rich condition as I rolled on the throttle. As I leaned the needle taper and clip height it got better. I went to a leaner main as well but that just helped it clear the excess fuel quicker whenned i rolled ro fill throttle but it was not necessarily the best for the top end performance so I went back up one size.

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