Engine heat causes hesitation?

[Bryan K.]

Hey guys, so I was running my HPI Baja yesterday afternoon and I noticed a small issue. I ran a full tank through of consistent runs for about half an hour, no issues. Checked the plugs, looked good, decent amount of smoke, everything ran smooth. I like to set it a bit richer than stock carb settings to be on the safe side, so sometimes it gurgles a bit when accelerating, but clears up after a couple WOT passes. I wait about an hour, then fill up a second tank. Everything is fine for about 20 min of run time. Tank is about 1/4 full but I do 3 WOT passes (about 3 seconds each run) and I get this odd cut out or hesitation for a half second or so. Still smoke coming out of the exhaust, so it doesn't seem like a lean condition. Would running the engine too hot cause this? I ran my car on tarmac, so there's a lot less resistance. It did this for the next 3 WOT passes. So I turned the car off, waited about 10 min. Fired it up and ran it for another 10 min without any of the hesitations issues. Ran perfect again. I'm not super concerned, since I know these carbs can be finicky sometimes. Maybe bad fuel, air bubbles or something got clogged. However, just want to make sure. I like to run my cars through the whole tank without stopping because idling too much builds up too much fuel/smoke. So is it heat related? Should I stop and cool the motor occasionally?

thanks guys.

 

[zoom10145]

Might be fuel starvation caused by fuel sloshing around in the tank and the clunk/pickup pulling in air momentarily. That happens to me, i use it as a way to know to stop soon or fill up the tank.

 

[pyroM!ke247]

Use one of these clunks. They wick fuel better. http://www.davesmotors.com/walbro-125-529-1-winged-fuel-filter.html

 

[Bryan K.]

Ah, I was hoping it wasn't a fuel starvation issue. The fuel tanks on these Baja's are so dinky, and because of air filter placement, there doesn't seem to be room to upgrade. I hate where the fuel filler hole is as well. Further reduces the amount of fuel you can put in as it spills out the side while filling. I get about 40min run time on my DBXL's upgraded 870ml tank. I'm kind of disappointed in only 20 min reliable run time on the baja.

That Walbro winged filter is interesting. I didn't realize that a wicking material was enough to keep the fuel flowing?

So anyways, heat shouldn't be an issue then? I should be able to run constantly without stopping till the tank's empty? I'm used to stopping my brushless cars to cool the motors/batteries. Not sure the proper procedure for gas powered cars.

 

[Seandonato73]

Lol, it's not a heat issue mate. I'd go with the fuel slosh theory as well. And the wing filter are pretty trick. Gotta remember these thing don't need much flow to run, so the capillary action in the wick works just fine in these little engines

 

[Bryan K.]

Cheers, I'll pick up a few of these filters then and put them in all my cars.

thanks