• 2 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     WR = 2st Enduro & CR = 2st Cross

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

All 2st Jetting Chat - Need Help? Post Your Questions Here

Have just had delivered my pwk 38 AS (thank you motorhead) and have no idea on how to jet to my bike. I have a 2004 WR250 fitted with FMF gnarly exhaust with standard tail pipe and use 97 rom fuel at 50:1 mix and am in jolly old england so is at sea level or there abouts and cold!!!
Am looking for a basic set up then i can fine tune from their. Any help greatly recvieved.
Thank you in advance
 
Find out what jets/needle are in it and for starters and report back. Do you have any extra jets available yet?
 
PowerKord said:
Find out what jets/needle are in it and for starters and report back. Do you have any extra jets available yet?
Click to expand...
Right I have no jets in the carb but do have what i think is a jd jet kit comprising of Blue, Red needle a 45, 42 main and 178, 180, 182, and 185 main. What would be a good starting point?
 
I think James will send some instructions along with the kit to get you started. Don't be afraid to experiment with changes. I had a JD kit in a KX I had and it ran really well.
 
The bike is fitted with a stock tmx so would i be able to check and use like for like jets that are fitted to that?
 
Just got back from a trip away and really want to get this carb on. As it has no jets fitted what one would you recommend fitting to get started?
 
Those are really big main jets you have. I would start with the 45 pilot, 178 main, and blue needle with clip set on third position.
 
any thoughts on jetting a 99 360 wit a 38TM Mik and an FMF Gnarly?
I will be riding 3000' to 7000' mostly about 4000 -5500' and lot's of single track
also taking a 93 360 same set up, just they are ported a little different but guess same jetting?
 
How should I rejet for an elevation drop of approx -350 metres?
Without rejetting would this result in a leaner or richer condition - i'm guessing richer?
 
Really, higher elevations have less air density than lower ones - at high elevations our engines are getting less air, so they need less fuel to maintain the proper air/fuel ratio?
What would I experience in terms of performance change if I rode descending through the entire elevation change without rejetting?
Also, how would going from a stock exhaust system to a less restrictive exhaust affect jetting?
 
SHY UK said:
How should I rejet for an elevation drop of approx -350 metres?
Without rejetting would this result in a leaner or richer condition - i'm guessing richer?
Click to expand...
If you drop elevation it will run leaner because it is set for the higher elevation with less dense air. You will be at a lower altitude with more dense air therefore you will need more fuel. That being said a 350 meter drop won't drastically effect it unless it was already set on the lean edge at the higher altitude.
 
Ok, nice - getting there!
And the prevailing logic is that 'breathier' pipes also tend towards leaner condition?
 
SHY UK said:
Ok, nice - getting there!
And the prevailing logic is that 'breathier' pipes also tend towards leaner condition?
Click to expand...
Yes, the engine is basically a pump. The easier it is for exhaust to get out,the more air it will draw in.This may require slightly richer jetting in some cases.:cheers:
 
Any circumstances where a 'breathier' pipe would result in a richer condition, for example reduced back pressure?
 
SHY UK said:
Any circumstances where a 'breathier' pipe would result in a richer condition, for example reduced back pressure?
Click to expand...
How jetting relates to a pipe is way more complicated than wether it "breathes" or not. The topic of pipe design would need it's own thread. As far a jetting relates to a pipe change it's best to give your bike what it wants by riding it and adjusting the jetting until it runs it's best for you. You can look at other's feedback and post your feedback to help others.

If you really want to understand what pipe changes really do, here is a link to get you going. http://www.google.com/search?q=2+st...9GsegyAHSiYGwBg&ved=0CEkQsAQ&biw=1635&bih=941
 
lankydoug said:
How jetting relates to a pipe is way more complicated than wether it "breathes" or not. The topic of pipe design would need it's own thread. As far a jetting relates to a pipe change it's best to give your bike what it wants by riding it and adjusting the jetting until it runs it's best for you. You can look at other's feedback and post your feedback to help others.

If you really want to understand what pipe changes really do, here is a link to get you going. http://www.google.com/search?q=2 stroke pipe design&hl=en&client=safari&rls=en&tbm=isch&tbo=u&source=univ&sa=X&ei=gSdLUZj9GsegyAHSiYGwBg&ved=0CEkQsAQ&biw=1635&bih=941
Click to expand...

Ok, thanks ..
one more thing ..
I have been reading that compared to an exhaust change, which is often little more than a placebo effect, a 'breathier' air filter will have significantly more effect on air/fuel mixture, again tending towards a leaner condition?
 
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