hard re-starts

[smokin al]

Hello, my Losi xxx-nt starts great when cold (first start), but if it runs out of fuel or stalls, it is very hard to re-start. Also, when trying to re-start and priming fuel, I can hear the fuel boiling in the carb/engine. Normal? Tips? Ideas? The truck runs great once started again and leaves a nice trail of smoke.
Thanks

 

[Candyman]

First hunch is that it's running hot. Hard restarts is common with that. Do you have a temp gauge? Just curious as to what temps the engine is typically running at.

 

[sl0eg1n]

sounds like vapor lock. this happens when the carb is so hot that it creates an air bubble at the fuel intake nozzle. you can do 2 things.

1: let the engine cool for 10 mins and try again
2: use canned compressed air and spray the outside of the carb body. during mains, this is what racers do if the car flames out during a pit and they can't start the engine due to vapor lock

 

[FastEddy]

2: use canned compressed air and spray the outside of the carb body.

I have seen this crack a carb body more then once. I have also seen it warp the body beyond use. Caned air comes out extremely cold and if the carb is hot, and it is, it can spell disaster.

This trick does work but it may have a high price to pay.

 

[Da Hellion]

to hot

Another alternative(kind of messy) is to pore fuel on the head and carb. I woulden't recommend doing this all the time but it will get you buy in a race. It takes a little longer then the air can to cool it but the aluminum will contract evenley reducing the risk of damage. If it keeps flaming out find out why and correct it. It sounds to me like you are just to lean so try richen the mixture a little

 

[Revo Rancher]

Yep, sounds like you are boiling the fuel before it gets through the carb. Definitely check your temps.

 

[rbmaxxbasher]

I had this problem with my savage 21. I had to give it some time to cool.

 

[emu67]

During the summer months, the carb gets naturally hot to the point that it likes to vapor lock if the engine isn't running to pressurize the tank. Same thing happens to my buggies in Vegas during the summer. Probably the best thing to do is wait until it cools down or make sure to refuel before it gets too empty if you want to keep running.

Oh - on a side note, during the summer, I've noticed that the buggy will tend to go lean on me when the fuel gets down about a 1/4 tank but when it's fuel it runs on the rich side. Both the sportwerks .26 and sh .21 behave this way at 100F ambient temperature.

 

[smokin al]

Hello all! Thanks for the tips! I'm not sure what temp I'm running at, but it sounds like the place to start. I'll borrow a gun and check it. Could a different fuel help it to run cooler? I have been using Trinity Platinum 20% and just picked up some Byron's 20%. The guy at my LHS said he has had good reports with the Byron's.
Thanks again for the warm reception for the newbie!

 

[ThunderTiger]

HMMM......sounds like my buggy when the temp gets up, all i can hear is the fuel going into the carb and sounding like a coffee percolator. I generally allow it to cool down, OR, poor cool (NOT COLD) water around the carb body. It may pick up dust and dirt on the outside body of the carb,m but it keeps you running. Another tip (which i may have read above) is to reel the car in and fuel up while its running. That said though, constant running brings with it high temps. Try running a buggy for 90 minutes without stopping the engine and check the temps then, WAAAAY high dude. I've found 30 minutes is a good run time for me with 15 minute cool down time inbetween. It works for me, but may not for other people.

 

[Plaidfish]

run time shouldn't really affect your temp as much as driving styyyyle.....if you're constantly on WOT you'll be hotter......I can run almost 1/2 gallon non stop (w/ exceptions of pit stops or minor repairs) nad still come in around 240-250......one thing I have noticed is the higher end mills (sirio .27/ VZ-b / P-5 / 421s) all run very cool compared to the mid and low end mills.....I think it's mostly because you want to have your cars power band in the middle of your throttle...when you use the cheaper mills you're constantly on the top of the throttle tryig to get more.......

 

[ThunderTiger]

Heya smokin al, everyone has to start somewhere, so it's nice that everyone can chip in and help out if they know of any way they can possibly be of help or give advice. BTW, Welcome to the boards.

 

[rossb]

When your motor gets hot the sleeve expands faster than the piston and you lose some compression. A hot motor is much easier to spin than a cool motor due to the compression loss. This loss of compression sometimes makes it hard to restart a hot motor, especially if you are using a pull start. Sometimes the only solution is to let it cool for a few minutes and when the sleeve tightens up a bit it will start right up.

 

[Plaidfish]

if your engine keeps doing this you might want to have the sleeve pinched.....cheaper than a new set and you don't need to do a full break in, just 1 tank of slow spurts...

 

[Diver6127]

run time shouldn't really affect your temp as much as driving styyyyle.....if you're constantly on WOT you'll be hotter......I can run almost 1/2 gallon non stop (w/ exceptions of pit stops or minor repairs) nad still come in around 240-250......one thing I have noticed is the higher end mills (sirio .27/ VZ-b / P-5 / 421s) all run very cool compared to the mid and low end mills.....I think it's mostly because you want to have your cars power band in the middle of your throttle...when you use the cheaper mills you're constantly on the top of the throttle tryig to get more.......

Also, if you're just bashing in the lot or field just going back and forth WOT, you'll get the hotter temps. In a track setting, turns, jumps and chicaynes are in the mix so you're always off and on throttle.

 

[Zaytri]

if your engine keeps doing this you might want to have the sleeve pinched.....cheaper than a new set and you don't need to do a full break in, just 1 tank of slow spurts...

UberNewb question.. What is pinching the sleeve, how does one do it, and what tools are needed? :hammer:

 

[smokin al]

Hey Guys, I just came in from running the ol' girl and think I got it dialed in good. I did change fuel brands and fattened it up some-don't know which did the trick but no more boiling fuel and I can feel that it is running cooler. Starts right up each time even when at running temp! Thanks again for the tips. I like my truck again!
Smokin Al

 

[c3racing0082]

Fattened it up did the trick. I'm sure the fuel brand didn't have anything to do with it.

 

[rbmaxxbasher]

I had trouble like that from blue thunder.

 

[Da Hellion]

Fattened it up did the trick. I'm sure the fuel brand didn't have anything to do with it.

I have seen fuel brands cause problems but it's not necessarily the brand .The way the fuel was handledbefore it arived at the LHS IE Loose cap,left in the sun,continsation