WF engine stalls coming out of sloping corners

Paul Hutt

I have a strange problem with the engine.

First some history. The engine would die after going about 6' and 3,500 rpm.

Cleaned the carb. To make sure the float was in the correct position I had the tech look at it. Float position was fine.

Took it to the track. Then the engine began to hesitate or stumble when I was just beyond the turn-out point. I had to pump the accelerator to get the engine to run as it should. If I did not do this, the engine would die.

This indicates to me that the float is not in the proper position, which is strange given that the tech said it was OK and had no problems on the level portions of the track.

When I got back home I found that overflow reservoir was dry. I ran it on the stand for about 5 minutes and the bowl had 1/2 to 5/8 inches of fuel below the top of the bowl.

I am afraid that if I tried to adjust it that I would make it worse. Is there a way that I can determine if the float needs adjusting by how the top of the floats position is relative to the top of the bowl -either with the top of the bowl being parallel with the ground or at the angle when it is mounted to the engine.

Or is there a way to determine if the float needs adjusting by looking at the pin that is below and touching the tab connected to the hinge and cylinder that the pin goes into. (I am now getting into an area that I do not understand.)
_________________
Race Grandpa
Panic Motorsports West

John Matthews · Posted: Fri Jul 08, 2011 2:34 pm Post subject:

Hi Paul,

If you turn the carb upside down the float should be roughly parallel to the bowl mating surface.

But, with the problems you've had I'm wondering if you're not having a fuel delivery issue before you get to the carb. Make sure your tank vent is clear so you're not drawing a vacuum which will stop fuel flow. Check your fuel lines for kinks, pay attention to any area which might be subject to binding while you're on track. Make sure your fuel pump pulse line is connected right and zip tie all pulse and fuel line connections. If your fuel lines are old or stiff replace them with new.

There really shouldn't be that much of a problem with the WF carb, it's a pretty simple device and can work reasonably well even when set pretty far from optimum. Hopefully this helps.
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John Matthews
Heartbeat Power, LLC.

Paul Hutt · Posted: Fri Jul 08, 2011 6:55 pm Post subject:

John Matthews · Posted: Sat Jul 09, 2011 5:09 am Post subject:

Yes, more or less level with the ground. I measure to the mating surface since I don't normally have the kart in my shop when I build motors. As long as there's a reasonable amount of fuel in the float bowl, which you have confirmed, it should work.

The guy on 4cycle might have a good idea for you about the angle too.

http://karting.4cycle.com/showthread.php?t=385619

Good luck,
_________________
John Matthews
Heartbeat Power, LLC.

Paul Hutt · Posted: Sat Jul 09, 2011 8:31 am Post subject:

John Matthews · Posted: Mon Jul 11, 2011 2:50 pm Post subject:

My guess is it's not the float level but not being there to actually work on it I can't say for sure. The best thing to do if possible is swap carbs with someone who's running fine. If the problem clears up then set yours up like theirs, if not you need to look elsewhere.

Are you the only WF at your track? I thought it was pretty popular in the northwest, find someone who can actually put their hands on your kart if at all possible.

Good luck,
_________________
John Matthews
Heartbeat Power, LLC.

Paul Hutt · Posted: Tue Jul 12, 2011 7:41 am Post subject:

John,

As you mentioned it could be an electrical issue. One person suggested the same because the problem only occurs when I am coming out of a right-hand turn. They suggested looking at the ground wire. Forgot to ask them what exactly I should be looking for and how to remedy the problem.

However, the fact that I have to pump the accelerator to keep the engine running would not seem to relate to an electrical problem.

WF are strong in IKF Region 6 - Especially with the Portland club. The club I belong to has had a real drop off in membership & participation in many classes. This year only 2 or 3 WF entries in club races. All of the extra carbs are in Portland!!!

Thanks,
Paul
_________________
Race Grandpa
Panic Motorsports West

Kevin Larson · Joined: 31 Mar 2010 Posts: 6

Paul,
We got a spare engine that's for sale, would be more than happy to bring it over to the track and try the carb or any other part needed, let us know. Nik's on vacation, he could bring it over anytime and help you out with your problem. Kevin

Paul Hutt · Posted: Tue Jul 12, 2011 8:52 pm Post subject:

Benn Herr · Joined: 18 Jul 2001 Posts: 1584

Had a World Formula several years ago that had a clogged pilot jet. The symptoms sound close to the same except it ran bad any time you wanted to give it gas, not just in some corners. You could have a combination of situations. It would be worth trying another pilot jet and see if it changes.
_________________
Benn Herr
Come see our Superkart Build Off @
http://www.lostenduros.com/?page_id=1534
beherr3@cox.net
http://www.southwestkarters.com/
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Kart Design
Chandler, Az.

Paul Hutt · Posted: Tue Jul 12, 2011 10:52 pm Post subject:

Thanks Benn, I will try that.

Rob Dutton · Posted: Mon Mar 12, 2012 9:06 am Post subject: