ATV Drag Racer Forums banner
1 - 20 of 68 Posts

·
Registered
Joined
·
92 Posts
Discussion Starter · #1 ·
Well, ever since i went to my 30oko's a few weeks ago, my bike has been falling flat on it's face at WOT for after 1-3 seconds. When i go 1st gear or 2nd gear through 5th wot using the override it does it every time. I hold it WOT since i've got an override.

I recently had bubbles in my fuel line so i figured that was the issue. To make that long story short, i took care of that. No more bubbles in the fuel lines. After some WOT run, lines are still full. My screens for my pet[censored] are clean(i cleaned them this morning. And i drilled out my gas cap etc. So fuel flow doesnt seem to be an issue. It's not like i have huge carbs feeding a cub or something. IMO i dont see why id need a dual pingel(sp?) pet[censored].

I thought it might be im too lean. I had 155 mains after the 158 plug chop looked a tad rich. This is the chop:
http://rc.superdave2u.com/MyBanshee/30oko%...n%204-28-09.JPG Yes it's two different plugs, sry. But now they are the same.

Well today i said what the hell and put in 162 mains. Same thing. Cutting out at WOT. I then checked my pickup on my flywheel with my feeler gauges. It's correct. I dont think it being too tight could cause issues like im having anyways. I just know it isnt too far. I've been there and one that. I wanna say it's now around .016-.019ish

You guy's got any clue why my bike is doing this? It pulls like a raped ape till it falls flat at WOT for a tiny bit. I tuned the needle, air screw idle and sync carbs. The bike is VERY VERY crisp. So crisp i am in fact suprised with how well i did it. I also been noticing that it wants to rev a little high after i come off the gas sometimes, especially a WOT run. I remember from my nitro r/c car days that was a sign of not enough fuel.

I bended a tab on my floats so fuel would stop pouring out the overflow line on one carb but the problem was there before i did that. The carbs were brand new and the carb place(carb parts warehouse) i called said they should be set. I think the guy said 19mm just for references. But i didnt check that. Maybe that was the problem all this time. Ill have to go buy a meter stick at the hardware store to check it.

I also did NOT do a leakdown test. That is also something i need to do.

Mods are:
4 mill crank, ported stock cylinders
19cc +2 cc domes (149psi)
cpis
162 mains right now(tried 162-155)
30 oko's
48 pilot
needle(i forgot but it's nice and crisp from 14-3/4), prob middle position).
air screw 2 turns out

I gotta head to work till 11pm. And this is really disappointing me. Ill check back then. Thanks.
 

·
Premium Member
Joined
·
1,245 Posts
The motor hanging at WOT is an easy tell that you are lean. Gas or methanol?

I would tell you to get a pingle and run a fuel pump. They are cheap items, and it is not worth losing a motor over 120 bucks.
 

·
Premium Member
Joined
·
1,953 Posts
WTH kinda plugs are those??? I think it's maybe a fuel prob and Ive used 52 mains in those carbs with like a 152-158 mainjet. Can you swap carbs. I think it needs a dual pingle but that might not be it either but then at least you have it.
 

·
Registered
Joined
·
44 Posts
Here is the problem that I had with my 4 mill. My bike would pull hard through third gear then WOT 4th-6th it would not pull and crap out. I could just get into the power band and it would nose over on itself.
First I thought electrical and chased plug boots, grounds and other wirring issues. Changed the main jet from a 165 to a 158. Plug check and the plugs were a touch to lean for me. I put in a set of 160's and found the ticket. I had a fat problem and the bike was getting to much fuel at WOT. Things are all good now pulls hard through every gear.

4 mill cub
35 pwk
Gasoline

Not sure if that helps.
Pingle valve is the only way to go. The lines are bigger and you can get them to run much more direct to the carbs keeping the gravity feed going the entire time.
 

·
Premium Member
Joined
·
3,418 Posts
Go stupid fat, like 175 on the main.
How long are you holding it WOT for...a brief second, or like 5, 10, 15 seconds long.
If it's longer...regardless...get a pingle to start.

As long as you're sure the motor is sealed (you said it was) the stator checks out, flywheel is good, plug wires/end caps are good...rule out all electrical first, then solve the fuel.

WOT for a long time, even on small carbs, can suck them dry with a good port job.

You could always remove a float and gain some volume in the bowls, too...
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #8 ·
I'll try to answer the questions one by one.

Koolguyson, it's a pump gas set up. 94 octane strait out the pump at 40:1. nothing too fancy, just a playbike.

Radar
, plus are NGK BR8ESi believe. Not gapped. Ran like is strait out the box as i always did.

tripledsracing, i have no idea what powerjets are. I thought they were something you have to add. Like it goes where the filter connect to it. Popular with alky/meth set ups. Or fuel hungry set ups. Correct me if im wrong.

Ill order up a dual pingle valve. I was talking to my builder and that's the first thing he recommended. Plus yall are making a lot of sense. Seems like a fuel issue. And a lean one.

Dave, im holding it wide open for 6-8 seconds is my guess because it's WOT till i top out in 5th for 1-3 seconds. If it doesnt wheelie up, it will do it in 4th. and the bike pulls pretty damn quick through the gears so maybe it is lean on the main even with 162's.

162 mains is the fattest i have so i will have to order some more. Ill order a good bit of sizes up as well as the pingle.

Damn i was planning to go to mississippi this weekend with a bud to finally ride in nothing but sand. Oh well
After i put the pingle in and jet up, i will update yall with that is what. I do appropriate all the help guys. Damn money pit.

edit* check this out. He might be on to something. However, drilling holes in my carbs isnt to my liking lol http://www.bansheehq.com/forums/index.php?...t&p=1006903 . Yall think it's worth a shot? Nevermind. I believe going fat on the mains like suggested and a pingle is way easier and safter. heh.
 

·
Premium Member
Joined
·
1,953 Posts
My daughters 108cc stroked piped 2 stroke quad can run her 30mm oko out of gas in about 8 seconds so i had to run both the reserve line as well as the main fuel line into a Y and then drill out the float seat a little bigger. It's got a 152 main. I think you can run one dry with your motor or basically anything bigger than a 152 main and gravity fed. Just a thought.
I'd replace the plug boots they sometimes give you probs and are cheap.
 

·
Banned
Joined
·
1,373 Posts
QUOTE (Radar @ May 22 2009, 05:32 AM) index.php?act=findpost&pid=43748My daughters 108cc stroked piped 2 stroke quad can run her 30mm oko out of gas in about 8 seconds so i had to run both the reserve line as well as the main fuel line into a Y and then drill out the float seat a little bigger. It's got a 152 main. I think you can run one dry with your motor or basically anything bigger than a 152 main and gravity fed. Just a thought.
I'd replace the plug boots they sometimes give you probs and are cheap.


also if the float adjustment is off will cause this problem my big bike done this just the other day because i had the adjustment off..you need to set them to take all the fuel you can get without fuel coming out the vent tubes..if i was you id invest in a pingel also and check the plugs and make sure its not bogging because its fat by what liftgate was saying it sounds like that might be the problem..if u are running gas then u dont have powerjets which i had a polaris on gas and it had something similiar to the powerjet and it worked alot like they do..
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #11 ·
I just ordered a pingle and fatter mains just in case. Should be here Wednesday. Ill throw on the pingle and see what shee does. Thanks. I wil hold off on doing anything else just to see if the pingle solves the problem.

As for removing the floats, wouldnt that cause fuel to contently run out of the vent tubes?

I really dont wanna spend $150 on billet bowls. So i might just sell my 30 oko's and guy some 35PWK's if i cant get it to work. 35's would help my top end im sure. But then i think my small pod filters wont work. Perhaps my throttle cable as well.
 

·
Registered
Joined
·
767 Posts
Just for some info, I run the 30's on my play bike. It will run 4.9's in 300ft which is no slouch. We sometimes gear it up to a 16 in the front for my wife to race at the dragstrip while I am running my drag banshee. It will run out through 6th no problem, so I dont know about needing a lot of major fuel system changes. Mine has the stock petcoc assembly too. I do however run my float levels pretty high, enough that it will overflow some out when casual riding.
 

·
Banned
Joined
·
1,373 Posts
QUOTE (RagunCajun @ May 22 2009, 11:51 AM) index.php?act=findpost&pid=43792What's the regular float height setting? 19mm?


really just mess with the adjustment until you get it to overflow and then go back a lil and should put u close..but what i do to adjust it is blow down the spout on your carb with your mouth were the hose goes and work the float up and down until u get it get close...if that makes since..lol..the air will stop when u raise the float so pretty much you wont the float to be even or up a lil..
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #17 ·
I just went modify the carbs with those two extra holes per carb like the guy on HQ said. I figured what the hell, it couldnt hurt. I tried it and it didnt work. I did clean all debris out and made sure the needle still sealed when seated.

To take ONE float out of each carb, you have to cut it out or what. Looks like they are stuck to the thing it's connected to pretty good. That's gonna be the last thing i try till my pingle comes in.

Oh here is something i noticed just now. The bike still wants to idle high after a WOT run where it cuts out. But the thing is, it did idle high a couple times just putting about 300-400 feet. I held the gas down the whole time but not all the way. I wasnt even in the powerband. Then when i let off to turn around the bike idled high. Starving for fuel that easy? Very odd to me.
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #19 ·
no no dave, i didnt leak test it. Im sorry if i made a typo.

I need to do that. I should of done that in the first place.....

I also tq'ed my noss head down to 15 lbs....i think they are 20. that would be the reason.
 
1 - 20 of 68 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top