where to go from here. jetting q.

[stainlesscycle]

Originally Posted by GMP

Bad reeds alone will do what you describe (sloppy low end), and I know for a fact and from experience that some of the fiberglass Boyesen reeds on the RAD valve get affected by modern pump fuel. If its an '03 I'd consider the reeds junk unless you replaced them yourself.

i would think it would be incredibly difficult to start and even ride with bad reeds... i had a reed crack on my 200 and it was tough to even keep it running enough to limp home.

i replace reeds every couple of years whether they are good or not. they will fail eventually, and it's something you cannot repair on the trail.

the good thing about your whole dilemma is you will know more about your bike then you did when you started

once you get it all sorted out you won't need to play with it anymore (unless you're like me and constantly tinkering/searching for the 'perfect' state of tune...)

[dank]

its a breeze to start. kick maybe 3 times if its been sitting and a little cold. choke or no choke. primed or not. and its not a major blurble at the low end, just a little sluggish, like the air screw is out of tune, even though i try to tune it most times i ride. oh well, i may as well check it anyways. im gunna take the carb off to check float height, so theyre going to be right there anyhow.

[iancp5]

Cool!

When I eventually find some time to strip down the engine I shall put the 36mm on. By the way I assume you know the CCK needle is a DDK shifted by half a clip position - in case you need some fine adjustment. I need check over the motor as it was sounding a bit odd during the Welsh. So odd I pulled out at the end of day 1.

[biggstr6]

This has got me thinking . How do you tell if the primary crank seal is leaking?

I'm a hypocondriact (SP) when it comes to bikes.

[GMP]

Originally Posted by iancp5

By the way I assume you know the CCK needle is a DDK shifted by half a clip position - in case you need some fine adjustment.

This is incorrect. The first letter defines the taper structure or series, in this case your comparing a C series with a D series, the C taper being leaner. The DDK and DEK are in fact a half clip equivalent different, which is why I mentioned them both. If your interested, get a copy of James Dean's Excel spread sheet that allows complete jetting spec comparisons across the throrttle range including altitude and temp corrections. Its very useful and informative.

I change reeds when I do a top end, and always find some minor fraying damage. Yeah if you have a big crack or missing part then the bike will be a bear to start, but smaller leaks can raise hell with the low end. I found a very strange condition on my '03 where the fiberglass resin on the Boyesen RAD valve reeds was being broken down by something in the fuel, the reeds were actually sticky to the touch.

Not saying this is your problem but it is all relatively easy to check and will eliminate any unknowns.

biggstr6,

If your primary crank seal is leaking you will suck trans oil in and the bike will smoke like you have a 10:1 mix in the tank. Ever see a bike like this? Looks like one of those trucks some towns use in summer that fog for mosquitos.

[stainlesscycle]

Originally Posted by GMP

If your primary crank seal is leaking you will suck trans oil in and the bike will smoke like you have a 10:1 mix in the tank. Ever see a bike like this? Looks like one of those trucks some towns use in summer that fog for mosquitos.

yep, leaky crank seals are pretty easy to spot. right side seal will fog the neighborhood. left side seal is instantly identifiable - bike will race and not return to idle no matter what you do (and will quickly hole a piston if you're not careful....)



jd's spreadsheet is great for experimenting on the bench - you can plug in minor changes and it charts lean rich compared to what you have. right ow i have a minor lean spot at 3/4 throttle. gotta plug in some numbers and see where i can get it a tad richer there...

on another note, i got a colortune from someone for my birthday - not something i would ever buy, but since it was free i'm gonna give it a try on a 4t and see how it works. should be neato.

[Fred1956]

Originally Posted by GMP

If your interested, get a copy of James Dean's Excel spread sheet that allows complete jetting spec comparisons across the throrttle range including altitude and temp corrections. Its very useful and informative.

Where is this spreadsheet you speak of...... I want one

[stainlesscycle]

google

JD_Jetting_2002.xls

[iancp5]

Originally Posted by GMP

This is incorrect. The first letter defines the taper structure or series, in this case your comparing a C series with a D series, the C taper being leaner. The DDK and DEK are in fact a half clip equivalent different, which is why I mentioned them both.

See what you mean!

But looking at a needle chart the length difference DDK -> DEK is 1.5 clips? Is that correct?

[GMP]

No, its .5 clip positions or about .45 mm between the two needles in the same position. if you get the spreadsheet you can verify this by comparing the two needles.

That spreadsheet is good, I jetted a GG125 from scratch with a different needle and the simulation was as close as it gets when I actually rode the bike. A large selection of needles are possible, except his, which are propriatary. If you can get the bike running pretty good with a DDK, the JD Blue will work even better.

Does that colortune work on a 2-stroke? We put a wideband AFR sensor/controller with a narrowband emulator in my brother's Buell XB9. It also has a small AFR gauge on the bars and can log complete ECU run time data to a laptop in a backpack. Very cool, really got the map dialed in close with that setup.