"Warm" starts

[KnightAzul]

A question about "warm" starts ...

Lets Assume that I have been runing the car for sufficient time for the engine to be at the right temperature and the High Speed Carb needle in the correct position to give a good mixture of fuel/air.

Ok, time for a refuel. Engine off, refuel, and then ... to start her up again what is the procedure?
Do I still need to prime the engine with fuel by pulling on the starter with finger over the stinger to draw in fuel? I assume that I don't need to change the High Speed Carb needle.

The reason I ask is that I had a few problems getting her going in this situation and don't understand why. The only thing that I can think of was the I wasn't priming the engine.

Thanks for any help,
KnightAzul

 

[Team 17]

When I completely run "out" of fuel, Yes I have to reprime the engine.

 

[Error401]

It depends, like Team17 said, if it's out, you gotta reprime. If you aren't out and there's fuel in the line to the carb, you might not have to reprime. Try starting it anyway without priming and if it doesn't seem to be getting fuel, prime it. It's easier to prime a little, that to deal with a flooded engine from over priming.

 

[Uncle Buck]

Most likely this......seems reasonable http://horizon.hobbyshopnow.com/articles/1284.asp?pg=5

 

[olds97_lss]

Man, i've had that happen on more than one occasion. I knew what it was doing, you could hear the fuel boiling, but i never thought to spray it with compressed air.

Although, the drastic change in temps may do more harm than good in the long run. By this, i mean it may crack the carb housing or the actual block on the engine. I've seen it happen in the 1:1 world, so it's possible.

 

[Error401]

That's whyalot of aftermarket engines (like the picco outlaw .26) has a composite carb. It doesn't conduct heat like metal carbs, and thus doesn't cook off the fuel entering the fuel nipple.

 

[olds97_lss]

But the throttle barrel wears out on you and starts binding. Had that happen on my maxx 2.5 at about 1/2 gallon. That was fun. Damn thing sticking wide open even with a throttle return spring. Even after cleaning it, it still stuck. Could have been because it was crappy traxxas product though.

 

[Error401]

Originally posted by olds97_lss
Could have been because it was crappy traxxas product though.

lol, could be, or maybe just a twitch with that carb in particular.

When I got my Picco 26, it had the wrong LSN and would die at half throttle. I like modding, so I used the barrel and LSN from a stock HPI 21BB. It fits perfectly, though I had to dremel the stop slot in the barrel a bit, and I haven't had it stick yet.

 

[olds97_lss]

I fixed mine to. I replaced it with about a grand of something else. OS 21 RG plus all the trimmings that make it bullet proof for beating the crap out of.

 

[Error401]

Dude, we're on the same frequency. If it broke, fix it so it will never break that way again. :thumbup:

 

[olds97_lss]

I always also try to make sure to build in a weak spot that's easy, cheap and quickly repaired. :cheerful:

 

[SkyMaxx]

Nice post Uncle Buck (excellent information), but I think this is a case of him not knowing whether he needed to re-introduce fuel to the engine or not.

Knight Azul, as mentioned, prime it until you see fuel moving into the carb. Then give it a go. In some cases, you may not need to prime it, but it can never hurt to give it a little goose to get it running.

 

[supermaxx258]

we i am refueling my engine i will usually just leave it runing if i am gonna go and drive agian and i dont let it run completely out of fuel.

andrew

 

[KnightAzul]

Thanks for the info.
Just a quick follow up on: "It's easier to prime a little, that to deal with a flooded engine from over priming ..."

What do I have to do if the engine is flooded? Wait a while and then try again?

Thanks,
KnightAzul

 

[olds97_lss]

Take the glow plug out and turn the vehicle upside down so the engine points at the ground, and rip the cord a few times. It will spit the fuel out. Put the plug back in and try starting it.

If you have a starter box, take the plug out, put a rag or paper towel over the head and turn it over with the box. Just make sure to cover the head with something. It will shoot fuel everywhere if you don't.

 

[KnightAzul]

On the subject of starting, flooding, etc ...

I just wanted to check that I am doing things right. For a cold start: I always set the HSN to back a rich setting (2.25 turns) and then after a few circuits to warm her up, lean her out to the ideal setting (1.75 turns). I am viewing this process to be a little like the choke on a real car which is required for a cold start. This is the way to do it right?

The reason why I am double checking this is that I just read somehere on this forum that a good running engine, does not need frequent needle changing.

Thanks,
KnightAzul

 

[olds97_lss]

If it's tuned right, you shouldn't mess with the kneedles at all to get it started. They should only be changed after it warms up. You get the fuel to the carb by plugging the pipe tip and ripping on the cord a couple quick times, set the trim on your remote so it opens up the carb a couple mm, put the glow stick on for 5-10 sec and rip the pull start until it starts. Pull the glow stick off after about 20 seconds of running and blip the throttle until it warms up.

This is what i do, and i'm normally running by the 3 or 4th pull. Thats at 30 degrees F out. Just don't let the engine cool off in colder weather. I start it in my drive way immediatly after getting outside and get it up to running temps. Then i kill it and put it in my 1:1 and drive quickly to where i'm bashing around. Then i immediatly start it and let it warm up while i'm getting fuel out, gloves on and stuff.

This works for me.

 

[KnightAzul]

The basic premise that I was using was that a cold start would required a richer mixture than a warm start. Much like a choke is required on a car on a cold start.

If I can achieve the richer mixture by setting the trim on my remote so that it opens up the carb a couple of mm on a cold start, then perfect! However, if my understanding is correct (which it probably isn't!) then opening up the carb with the throttle trim would not do anything to the mixture?

A slightly confused,
KnightAzul

 

[olds97_lss]

Your right with the choke theory, but it's not necessary. I start mine when it's 20degrees f outside the way i described and i don't have any problems. I just isn't a good idea to be changing needle settings all the time if you don't have to. You will wear out your o-rings more often which will cause air leaks. I made the mistake of always futsing with it on my first engine. Within a 1/2 gallon, my carb was getting air leaks all the time.

 

[KnightAzul]

Thanks olds97_lss.
I was a little worried that all these adjustments to the HSN would wear some parts out!

I'll give your suggestion a try.

KnightAzul