PW80 oil gas ratio - and stock screw settings?


13 replies to this topic
  • a_gunslinger

Posted October 20, 2006 - 02:26 PM

#1

I disabled my fuel injector and may have mismixed. Bike runs like crud now. I was messing a little with the the carb settings screws because when you gunned it or it landed off a small pee wee hill it would stall (rich or lean)?
Also, my 10 yr old saw me doing this and took the liberty of adjusting all 3 of the screws himself!!!! All out of whack now.

Anyone knwo what the proper self mix should be since the PW80 is
norotiously rich from factory?

and

Anyone knwo the stock fuel/air/idle screws settings to start fresh?

Thanks

  • yamahas rule

Posted October 20, 2006 - 09:07 PM

#2

huh........ shouldn't this be in the yamaha two stroke forum?

  • a_gunslinger

Posted October 21, 2006 - 08:16 AM

#3

Ummm, maybe. Last PW80 responses I got came best from this forum.:devil:

  • RCannon

Posted October 21, 2006 - 09:27 AM

#4

I believe removing that injector was a mistake. That carb is jetted to run with the injector in mind. The oil gets injected right into the carb throat if I remember correctly.

To run without it you'll probably need a much larger main jet. The jets for the pw's were difficult to find and expensive. Everythign had to be ordered in. See if you can repair the injector.

  • a_gunslinger

Posted October 21, 2006 - 11:22 AM

#5

I believe removing that injector was a mistake. That carb is jetted to run with the injector in mind. The oil gets injected right into the carb throat if I remember correctly.

To run without it you'll probably need a much larger main jet. The jets for the pw's were difficult to find and expensive. Everythign had to be ordered in. See if you can repair the injector.


I only disabled it after a ton of PW80 owners told me that when they diabled it and mixed their own they saw marked improvements. Actually, even the dealer suggested it oddly enough. I was hoping my logic was wrong in the mixture. I was repeatedly told that the PW80 comes way too rich from the factory regarding oil/fuel mix. So instead of the usual 20:1 mix I ran 30:1.

Hmmmm.... will reconnnect injector, but only after ruling out all else. I did put a larger main it also. Too many people have done this with positive effects for me yo discount it at this point. But your point is well taken - thanks!

  • RCannon

Posted October 21, 2006 - 01:21 PM

#6

I worked on a PW 80 here in utah. My altitude and temp may have been different. It is about 4500 feet and it was 80 degrees when I worked on it.

We had it running quite well with a main jet two sizes smaller thna stock. It ran quite rich in stock form.

Have you messed with the "airbox" and added holes in it??? If I remember right that thing was so restrictive the bike was almost waterproof.

  • a_gunslinger

Posted October 21, 2006 - 01:55 PM

#7

I worked on a PW 80 here in utah. My altitude and temp may have been different. It is about 4500 feet and it was 80 degrees when I worked on it.

We had it running quite well with a main jet two sizes smaller thna stock. It ran quite rich in stock form.

Have you messed with the "airbox" and added holes in it??? If I remember right that thing was so restrictive the bike was almost waterproof.


Yes, I have two new vent 1" holes on either side of the airbox. There is a specific K&N filter that can replacethe whole airbox/filter assembly - but not willing to go that pit bike route for this. I just need some optimal performance out of this bike until my 9 yr old get a little bigger and can step up. We saw a PW80 that ripped pretty well and just sounded crisper. He said all he did was diable the oil injector to get a better mix (24:1 I think) and rejetted a little, and put on an after market exhaust. I have the exhaust and oil injector poart done, just need to get my oil/gas mizture right and the jetting relative to the new premix........ I think :devil:

  • RCannon

Posted October 21, 2006 - 04:07 PM

#8

I would appreciate hearing about a solution to this problem when you find it. I have a feeling I am going to be back inside of ours again.

  • DirtBikeDude409

Posted October 21, 2006 - 08:48 PM

#9

you should have never taken the injector out....
like others said, that was your problem.

  • a_gunslinger

Posted October 22, 2006 - 06:36 AM

#10

I would appreciate hearing about a solution to this problem when you find it. I have a feeling I am going to be back inside of ours again.


I did find out the air/fuel stock setting is 1.5 turns out. Idle is a setting I think they detail in manual on how to set. Will report back.

  • a_gunslinger

Posted October 22, 2006 - 06:38 AM

#11

you should have never taken the injector out....
like others said, that was your problem.


Thanks for the reply. While this makes sense Im actually pretty suprised to hear you guys say this adter so many told me it works great. Oh well, we will find out :mad: Fortunately, I just cut the oil feed tube from injector to carb and plugged the ends. Would be an easy repair should I need to.

  • DirtBikeDude409

Posted October 22, 2006 - 08:43 AM

#12

Well I used to have a PW80 I got for super cheap and kept it to mess around with.
I took ou the injector too and caused nothing but the sme problems you stated.

  • a_gunslinger

Posted October 22, 2006 - 03:31 PM

#13

Well I used to have a PW80 I got for super cheap and kept it to mess around with.
I took ou the injector too and caused nothing but the sme problems you stated.


Interesting. I will keep you posted.

  • a_gunslinger

Posted October 23, 2006 - 04:23 PM

#14

OK. So the bike is running much better now. I think the track side carb repair resulted in a funky float issue. Float was way off from my man handling it the day it got stuck and gas was streaming out float bowl nonstop.

Its running pretty well now. Fires now on first kick. Has a very slight hesitation I think I can tweak out with main jet change and/or better fuel:oil ratio. I stepped main down to a 120 (from 125). My question now is what ratio do you think is in this bad boys best interest? From what I can tell from the manual its a 24:1 ratio gas:oil. That would explain the general consensus that they come to rich. I am running 40:1 in it now. Thoughts? Appreciate everyones help.





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