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PJ jetting advise

Posted: August 6th, 2008, 4:42 pm
by eyesky2002
Got me a stock 39mm PJ carb on my 94 stock 500, stock expansion chamber with PC 304 silencer. 1,200' average elevation with midwest humdity and 80-90 degree average temp. Got a new set of OEM reeds on the way, want them on and to play with jetting before I commit to a new PWK carb. So I need to guess-t-mate jetting, currently I have a 170 with 55, 1.5 turn out and 1368N neddle on the middle clip.

Bike is hard starting, once started idles fine. but gassy. When riding it bogs idle to mid, then rips nice and crisp thru mid and falls with a big bog on the top end... Got the drippy, oil spitting silencer too, seems way rich!

Posted: August 6th, 2008, 4:57 pm
by Uzi
Bog usually means lean sputter or blubber is usually rich.
Try 2.5 turns on the air screw if your bog is more like a blubber you might end up with a size smaller on the pilot same on the main I would try a 168. I'm pretty sure I'm on 168 main and 55 pilot right now too. Almost identical conditions 1000-1500 elev 80-95 temp with 50-75% humidity in SW Nebraska. And I know for I'm too rich on the bottom.

Posted: August 6th, 2008, 5:03 pm
by AlisoBob
Uzi wrote:"Bog" means REALLY lean, "Sputter" or "Blubber" means rich.
Yup........

I call rich, "Chugging" .....
Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chu
g.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug....
.Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chu
g.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....Chug.....
Chug.....Chug.....Chug.....Chug.....Chug.....

Re: PJ jetting advise

Posted: August 6th, 2008, 5:34 pm
by 100hp honda
eyesky2002 wrote:Got me a stock 39mm PJ carb on my 94 stock 500, stock expansion chamber with PC 304 silencer. 1,200' average elevation with midwest humdity and 80-90 degree average temp. Got a new set of OEM reeds on the way, want them on and to play with jetting before I commit to a new PWK carb. So I need to guess-t-mate jetting, currently I have a 170 with 55, 1.5 turn out and 1368N neddle on the middle clip.

Bike is hard starting, once started idles fine. but gassy. When riding it bogs idle to mid, then rips nice and crisp thru mid and falls with a big bog on the top end... Got the drippy, oil spitting silencer too, seems way rich!
your not far off, get a variety of jets from sudco and tweek it alittle. the 1368n needle will work from 0-6500' , while not the best choice at higher elevations it still works fine for the weekend warrior

Posted: August 6th, 2008, 6:17 pm
by eyesky2002
Uzi wrote:Bog usually means lean sputter or blubber is usually rich.
Try 2.5 turns on the air screw if your bog is more like a blubber you might end up with a size smaller on the pilot same on the main I would try a 168. I'm pretty sure I'm on 168 main and 55 pilot right now too. Almost identical conditions 1000-1500 elev 80-95 temp with 50-75% humidity in SW Nebraska. And I know for I'm too rich on the bottom.
Well if your in Lincoln, then we are the same as I am in basiclly in Omaha.

Posted: August 6th, 2008, 7:52 pm
by bigpower
I've been chasing a similar problem with my 01. I'm running a 52 pilot in it, 168 main. Elevations are close, but 70-80 degree range. I'd also check the crank seals and for a crack in the pipe. My PC had a crack in it, not enough to notice, but enough to make a difference.

Posted: August 6th, 2008, 9:02 pm
by Uzi
eyesky2002 wrote:
Well if your in Lincoln, then we are the same as I am in basiclly in Omaha.
Wow a hoon thats actually close by. Where do you usually ride? We need to get out and hit a local spot or two. I used to have a membership at the track near Union about 45 mi south of Omaha but let it go this year. I still do day ride out there once in awhile. Let me know if you are going somewhere close I'd love to ride with another cr500. Although your AF would blow my old 85' out of the water, I've watched you build very cool :cool:

Posted: August 7th, 2008, 4:32 am
by eyesky2002
I actully live in Council Bluffs, was dating a girl in Lincoln and was down that way alot up till recently.

05-07 when I had my 2nd Quadzilla, I rode at the Missouri River riding area on the Iowa side at the South Omaha bridge. It's been closed with them building the new bridge and then the June flooding; just reopened Saturday. Nice sized area, trails in the trees and along the river and a couple bermed in small track, maybe a double or 2 nothing special.

I have never rode a MX track around here on anything other then a pit bike just to be a stooge and that was up in Persia, Iowa at the 3 Oaks track. My buddies kids races 65SR and 85JR in both east Neb and western Iowa, think it is the Full Throttle series and the SouthWest Iowa series.

How is Union, I know a lot of the ones I have been to in Neb seem hard packed, with dry and loose layer on the top. I like the Iowa ones, all seem to be cut in a corn field and have nice rich, loamy, brown dirt!

Anyways once I get this thing track worthy (ie. easy starts and balls out power :lol: ) we will have to hook up. Goona take me a minute or two to get in the swing of things, have not been on a real MX bike since I moved here in 96. Do ride a rocket on the street, had the Qracer for a couple years and am always test riding my buddies kids things when I wrench on them, so I should be ok :wink: