jetting 33pwks

[Justintoxicated]

Ok so I have 12 port stock cylinder Noss Head and I think 20cc domes, but maybe 19 I don't remember.

 

Anyways I have Billet Intake with no crossover tube, and 33 pwk's

 

I have a CEL needle I believe it is on the second clip from the top, not sure on my pilot and I have 158 mains I believe. It was running great when it was around 77 degs out. But ran ok up in the 100's too. I would say your pretty close. Maybe try playing with your gearing, I have a 14 tooth on the front and 40 on the rear and it pulls nicely. you have to be wound out in 5th to pull 6th.

 

I don't know why you are melting plugs, I had problems with my Noss head Domes causing the plugs to back out. The domes were not cut properly cauing them to bounce around a little in the head which caused slight coolant leak (sometimes) and the bike to run like ass untill I replaced the other dome as well (which I could not identify anything wrong with, and it was not leaking coolant). Also what is this copper washer for the Noss head you are talking about? Mine uses O-rings no copper washers...

 

Check your domes and make sure they don't have any burn marks on them, make sure they don't have marks from bouncing around. After A few months mine showed some burn marks (on top and side) near the little tab that is supposed to keep them from rotating around.

 

make sure they fit flush in the head and there is 0 play. (mne were flush and no play but since only the alignment tab was holding them up the pressure eventualy pushed it into the soft aluminum head and thats how we discovered the problem (dome was cut too low but the alignment notch was the correct height).

 

Oh yea we thought it was my stock carbs reeds and jetting that was causing problems at first too. When I changed to 33's it was a little better but still had issues (All too Familiar). Finaly we found the real culprit which turned out to be the domes. I think you should look for other possibl problems, a leak down test was the answer for me.

 

Actualy Even after that I found there was a problem with my stator as well! Go figure! it was working but not providing a hot enough spark, it was an older ricky stator and they have since changed the design (caused problems on some ported banshee motors). So it can be frustrating trying to jet the Banshee when there are other issues (for me bad domes and bad stator and new carbs and jetting) all at the same time. It took over a year to figure it all out.

 

If your bike is breaking up your too rich or have fowled plugs, it's reving fine but not super clean clean and does not feel like it is making the correct power for the RMP your too lean.

Edited May 2, 2007 by Justintoxicated

[tbd]

allright i did a little riding from the weekend till today, about an hour and a half on the trail tech. just to be safe i put the stock cdi back in to get the timing back to normal, and i put a bunch of octane booster in the tank. took it easy, kept it half throttle and down, constantly moving the throttle as well. so this afternoon i did a compression test and after it was warmed up it read 150 psi for each cylinder. is this ok for pump gas? or should i have more time on the engine before i can get an accurate reading. also i'm a little fuzzy on how to check the squish. is there a paticular solder u need,and can i shove it in the spark plug hole? TIA

[Justintoxicated]

allright i did a little riding from the weekend till today, about an hour and a half on the trail tech. just to be safe i put the stock cdi back in to get the timing back to normal, and i put a bunch of octane booster in the tank. took it easy, kept it half throttle and down, constantly moving the throttle as well. so this afternoon i did a compression test and after it was warmed up it read 150 psi for each cylinder. is this ok for pump gas? or should i have more time on the engine before i can get an accurate reading. also i'm a little fuzzy on how to check the squish. is there a paticular solder u need,and can i shove it in the spark plug hole? TIA

 

I would run 50/50 race gas with that compression on a new motor. The cranking pressure ont he ported motor will be a bit higher plus when I got mine it went up about 15 PSI as the rings seated. Better safe than sorry. On the squish I'm not really sure how to measure it so I will let someone else chime in there. I would think you would need a micrometer or something.

[wesw]

to check squish your going to need some solder, remove the spark plug, kinda bend the solder in an L shape. and out the part towards teh side of the piston to be almost the same way your wrist pin is. and then hold it there and have someone kick your starter. it should mash it. then remove take a micrometer and mearsure the thick ness of the smashed part. should be like .040 or some number.

 

if your at 150 now and not really broke in it might go up once the rings really seat in. if you dead set in pump gas, leaving the timing alone for a bit to see say in like a couple of tanks what the warm compression is. if 155psi + your on the verge with ported motor and 91 octane.

 

solutions: run some 100 octane if you can get it,

you might call jim up and get some new domes that are cut to be safe with pump gas.

no advance the timing up much of any. couple of degress maybe, you will have to watch your plugs, if they rattle or you pull them and they are gray or very pooffy looking your knocking. then you could back some timing off.

 

personally i think your pump gas is shit up there in nj, im sure they have some weak ass blend for epa bullshit, ks has nothing so they just make gas, screw the epa lol, well not really. i think is a bit better around here.

 

you might end up with some 22 domes who knows.

 

 

did you try my jetting ??

[tbd]

sorry i haven't replied i have been working around the house. tommarow i'm going to get some race gas. so should i drain what i currently have in there or just run the tank out taking it easy? btw i do know from experiance with the yfz that the gas around here sucks, stuck floats every two weeks. the gas i get up north was never a problem.

 

i am going to jet it to what u recommended tommarow as well, and get a hold of some solder and check my squish what should it about be? .040?

[Justintoxicated]

sorry i haven't replied i have been working around the house. tommarow i'm going to get some race gas. so should i drain what i currently have in there or just run the tank out taking it easy? btw i do know from experiance with the yfz that the gas around here sucks, stuck floats every two weeks. the gas i get up north was never a problem.

 

i am going to jet it to what u recommended tommarow as well, and get a hold of some solder and check my squish what should it about be? .040?

 

I want to be clear that I am not recommending you jet to my specs. This is what works on my Bike at Glamis (about sea level) in warmer weather. When it gets colder I like to bump it up a size. MY motor is a dune 12-port not mx-12-port as well, ands each bike is a little different. My setting MAY work fine for you but they may also be too lean if it's colder where your located or different elevation etc. You sound like your on the right track though.

 

As for your gas, if you can just mix some race fuel into it thats fine, or drain it into a jug and mix it there

 

Also what kind of compression tester are you using? Do you have access to a know accurate one? I think I'm running 19cc domes and have around 165-170 PSI and timing advance 4 deg, running about 100 octain (F&L 111 mixed with 91) My compression slowly crept up almost the whole season (but I don't get to ride that often). It is back on it's way down now.

 

Good luck.

Edited May 5, 2007 by Justintoxicated

[Justintoxicated]

Picture of messed up dome after running it for a long time http://desertrat.servehttp.com:8080/Desert...pg&d=d.html

 

Notice the mark in the notch where the head was not allowing the dome to properly seat. it was like a whole 1000'th of an inch off

Edited May 11, 2007 by Justintoxicated