[ShawnGny]

I believe the OEM petcock flows higher rate on reserve than when "on" in normal working condition. Hope to hear you're ripping it up soon! Good luck man

Really? Thats interesting.....any idea why?

 

[2Nubs]

I want to say it was because when using reserve the "on" position is actually flowing as well if you have enough fuel of course. The hose to the carb is only so big though so I'm not sure it's that big of a difference. I've been trying to find where I found that info so I could read more, but no luck so far.

 

[ShawnGny]

Thanks Nubs, lmk if you find anything out.

I want to say it was because when using reserve the "on" position is actually flowing as well if you have enough fuel of course. The hose to the carb is only so big though so I'm not sure it's that big of a difference. I've been trying to find where I found that info so I could read more, but no luck so far.

 

[2Nubs]

I was incorrect. If you remove the nub from the face plate it will allow you to spin the petcock to the opposite of "off". That is when it will flow from both.

Going to send you a PM

 

[Big_Mike]

When you modify the petcock the fuel is flowing from both the “on” and “reserve” portions of the petcock essentially giving you fuel from both sources, hence better flow.

I have a modified OEM petcock with the stop grinded down which flows more fuel than the stock petcock in regular form. I would sell it to you if you are interested. It’s got a brand new o ring. I’d be using it myself but I went with a pingle..

 

[ShawnGny]

Thanks Mike for the reply, I just grabbed a brand new petcoct from BDT, Ill do the mod on that since I spent the money. I saw the pingle but was nervous to try something new since I was going to tune it today. Again thank you.

When you modify the petcock the fuel is flowing from both the “on” and “reserve” portions of the petcock essentially giving you fuel from both sources, hence better flow.

I have a modified OEM petcock with the stop grinded down which flows more fuel than the stock petcock in regular form. I would sell it to you if you are interested. It’s got a brand new o ring. I’d be using it myself but I went with a pingle..

 

[SandSlinger]

Well any news?

 

[ShawnGny]

Well any news?

Yes it did 45 horse with knobbies, I didnt think about street tires, been a while since I dyno'd something. We were thinking maybe around 50 with better tires, tore the shit out of my holeshots.

I had to drop it down a main and raise the needle. But when we would hit it from 4,000 on it would lean out until 6,000 then catch up with fuel and be fine up to 10,500 redline. Do you think thats a air screw adjustment, I ran out of time there was many people waiting to get tuned......I could have used one more run.

 

[SandSlinger]

My 310 made 54 I believe on a super rich tune. I don't know anything about rpm s or anything but if it cleans out by 6000 that would tell me based on your description it would be needle related. I feel as long as your airscrew is set correctly it shouldn't need to be touched again. I think ur air screw is fine where it's set at.

 

[matuus]

45 horses low 4 330. your dyno reading low #. 310 reading 54 horses. dyno reading high #. dyno only good 4 testing. not comparing.


Sent from my iPhone using Tapatalk

 

[ShawnGny]

Heres the max power and fuel/air.

 

[SandSlinger]

My 310 could have made a few more hp on the dyno if the ding bat knew how to tune a 2stroke. Mine was Hella rich at the time. I saw your spark plug pics its diffently rich. So you got a starting point, now its fine tuning.. Curious if you have done a compression test yet?

 

[ShawnGny]

My 310 could have made a few more hp on the dyno if the ding bat knew how to tune a 2stroke. Mine was Hella rich at the time. I saw your spark plug pics its diffently rich. So you got a starting point, now its fine tuning.. Curious if you have done a compression test yet?

Same here, I kept asking does this graph mean its lean mid , top........he kept switch it up on the computer bringing up old runs to compare then getting confused.....mind blowing......he had my head spinning.

No compression check, those things are pricey and cant spend right now, saw on on ebay used but was a little worried about getting it. I think Im going to put the clip back on the third notch, its on 4th down right now.

 

[SandSlinger]

Yah I made the mistake of going to a four stroke guy to tune my 2stroker. Good idea on putting it back on 3rd slot. It's a dgh needle correct?

 

[ShawnGny]

Yah I made the mistake of going to a four stroke guy to tune my 2stroker. Good idea on putting it back on 3rd slot. It's a dgh needle correct?

Same here, he brought out the diagram showing me how it was easier to adjust a 4 stroke because it has so many different points, compared to where the 2 stroke has the 3. I understand, Ive dyno'd 5 of my 4 strokes........horrible experience lol......I felt like shit when I left him.

I think I found a good 2 stroke guy around here, Im going to call him tomorrow. Thing is my reservoir was leaking coolant, now it could have been just out of the cap because of the whoops, but is that what would happen if it were over heating? The whoops were huge I actually almost went over the bars, kinda thought my R was going to handle them like my YFZ but the suspension isnt set up yet and maybe the difference in weight? Blew my shoulders and elbow out, had to use every bit of strength from not going over the bars. It sounded so good I just ripped through the gears into fourth and sat back but it was rough. I scared the shit out of my self

Im going to drop the needle for sure and I think I may just going up in the main, to where it was with a 172 or maybe 175.

Did you have street tires on when you dyno'd??

 

[SandSlinger]

Yah he put on dyno tires. Mine was always blubbery in the mid range, I switched from 3rd or 4th slot with no real improvement or change. Never did get to switch to the leaner cel needle liked I planned.
How does yours run? Blubbery ? Your plugs looked black as is I wouldn't up the main I think your fine on that.

 

[ShawnGny]

Yah he put on dyno tires. Mine was always blubbery in the mid range, I switched from 3rd or 4th slot with no real improvement or change. Never did get to switch to the leaner cel needle liked I planned.
How does yours run? Blubbery ? Your plugs looked black as is I wouldn't up the main I think your fine on that.

It ran good. Im not sure about down low though, I thought it may be bogging but the place was whooped out so bad I might have been bogging it myself. Also I haven't rode a 2 stroke in 15 years, Ive been 4 poking for a long time.

That plug was actually in from dynoing also, so it's not good for judgement. I should have the beadlocks for it tomorrow so I think Im going to ride down south, theres a big place with 6 tracks. They have a super long driveway, Im going to do a plug test there, just wide open and thats it. Rip it on the track a little bit to start trying to dial in the suspension a little bit. Im pretty frustrated with the tuning at this point.

 

[SandSlinger]

Yah I hear yah on the tuning its frustrating especially when there is limited places really close to play around tuning it. I wish I had property to really play around with tuning, but I dont. I live in the city with really suspect neighbor's. If your alittle rich and not fouling plugs then leave it be. Better to be rich then doing rebuilds haha.

 

[ShawnGny]

Yah I hear yah on the tuning its frustrating especially when there is limited places really close to play around tuning it. I wish I had property to really play around with tuning, but I dont. I live in the city with really suspect neighbor's. If your alittle rich and not fouling plugs then leave it be. Better to be rich then doing rebuilds haha.

Thats what I was thinking also. Thanks man, I appreciate all the replies.

 

[2Nubs]

Try to get some video if you can Shawn. I know some of the old heads can tell if ones running solid just based on the sound. If you're alone you can always set your phone up on a fence post or what not and let it record. Just an idea that might get more people helping. Have fun!