My rc nitro hpi rs4 dies when close to full speed any ideas?

[Dannyharn]

When I open up full throttle it Boggs out

 

[D3MON]

When I open up full throttle it Boggs out

how are your temps? sounds like either rich on the HSN, or very lean on the HSN.

 

[Dannyharn]

how are your temps? sounds like either rich on the HSN, or very lean on the HSN.

i have that screw even with the outside rim. I think it’s running hot

 

[Dannyharn]

how are your temps? sounds like either rich on the HSN, or very lean on the HSN.

What does it mean if it’s Smokey when hitting the throttle?

 

[D3MON]

What does it mean if it’s Smokey when hitting the throttle?

thats good, means you are getting enough fuel. if you see no smoke coming out of the exhaust that means you are too lean and will damage the engine.

i have that screw even with the outside rim. I think it’s running hot

even with the outside rime means you are probably at factory settings.
factory settings are really rich, when you get the truck warmed up, tighten the HSN 1/8 of a turn, then run a few WOT speed runs, then if that is helping it, tighten it another 1/8 turn, then repeat until you are getting good power and there is still a plume of blue smoke when giving it gas.

 

[Dannyharn]

thats good, means you are getting enough fuel. if you see no smoke coming out of the exhaust that means you are too lean and will damage the engine.


even with the outside rime means you are probably at factory settings.
factory settings are really rich, when you get the truck warmed up, tighten the HSN 1/8 of a turn, then run a few WOT speed runs, then if that is helping it, tighten it another 1/8 turn, then repeat until you are getting good power and there is still a plume of blue smoke when giving it gas.
[/

Thank u bro I appreciate ur help.

 

[cbaker65]

If it gets hot & has a gurgly noise when it shuts off ,then it is a lean bog!

 

[Arrmajunk]

When I open up full throttle it Boggs out

your not very clear, does it bogg from stationary or does it drive well until you get towards Max vehicle speed
If it idles for a Long time with out clogging up I’d say it’s rich if it idles for a while and RPMs become a bit erratic I’d say it’s too lean .
Your best off starting over from factory settings if your unsure and take it from there , try the main needle around 2/3 turns from closed and the side needle flush, and just nik
Either way accordingly .

 

[Dannyharn]

So I took it out yesterday and it takes a while to start. If I use the brake it dies. It’ll run for a minute then die and then I have to put it on full throttle to start it again. I try to adjust needle but it seems to do the same thing every time

 

[cbaker65]

So I took it out yesterday and it takes a while to start. If I use the brake it dies. It’ll run for a minute then die and then I have to put it on full throttle to start it again. I try to adjust needle but it seems to do the same thing every time

I think ,the best thing to do in your case ,is to start out with the back ground history of your car ,it may not sound important to
you or to some ,but it is very important to getting your car up & running!

Ok ,how long has it been sitting ,have you ever tuned the carb after break-in when it was new ,or is the car second hand?

This is important ,because of the age of the car ,things can go bad an dry out ,thus ,not getting a good seal on the stuff
& parts that need to be sealed or old fuel that may have been left in the engine or tank!

These things are very important!....

 

[Dannyharn]

I think ,the best thing to do in your case ,is to start out with the back ground history of your car ,it may not sound important to
you or to some ,but it is very important to getting your car up & running!

Ok ,how long has it been sitting ,have you ever tuned the carb after break-in when it was new ,or is the car second hand?

This is important ,because of the age of the car ,things can go bad an dry out ,thus ,not getting a good seal on the stuff
& parts that need to be sealed or old fuel that may have been left in the engine or tank!

These things are very important!....

I bought it brand new 4 years ago and broke it in tried tuning it. Ran great. Broke a part and let it sit for the last 3 years and 10 or so months. Just replaced the part. I’ve already been through 2 tanks testing it trying to get it right.

 

[cbaker65]

I bought it brand new 4 years ago and broke it in tried tuning it. Ran great. Broke a part and let it sit for the last 3 years and 10 or so months. Just replaced the part. I’ve already been through 2 tanks testing it trying to get it right.

OK ,this is important to know ,because no matter how much that you try to tune the engine ,it doesn't matter ,if
the tank does not seal an hold the pressure or if the internal fuel filter is half clogged ,or dried up needle seals!

What have you done to the car as far as maintnance an checking that stuff out? .Also ,is there any leakage around
the cylinder head or the carb?

 

[Arrmajunk]

So I took it out yesterday and it takes a while to start. If I use the brake it dies. It’ll run for a minute then die and then I have to put it on full throttle to start it again. I try to adjust needle but it seems to do the same thing every time

It’ sounds like your idle screw, a tiny little screw in the carburettor barrel . So with the engine not running pull the brake full on, the barrel shouldn’t be able to quite fully close.
you want to see a Couple of MM gap in the barrel with the brake full on. Try that it should at least stop the engine from stalling ?

 

[Dannyharn]

OK ,this is important to know ,because no matter how much that you try to tune the engine ,it doesn't matter ,if
the tank does not seal an hold the pressure or if the internal fuel filter is half clogged ,or dried up needle seals!

What have you done to the car as far as maintnance an checking that stuff out? .Also ,is there any leakage around
the cylinder head or the carb?

No leaking anywhere I bought new gaskets for engine to muffler new screws and loctite but I think the gasket that seals the gas tank cap is gone!

 

[Arrmajunk]

No leaking anywhere I bought new gaskets for engine to muffler new screws and loctite but I think the gasket that seals the gas tank cap is gone!

Yes? I was thinking a tuning issue , but of coarse air in the system will starve it of fuel too.

 

[Applianceguy]

When I open up full throttle it Boggs out

İts because your throttle end stop is wide open adjust it two 3/4 wide open

 

[Rolex]

İts because your throttle end stop is wide open adjust it two 3/4 wide open

Actually, I've never backed off the end stop. If the HSN is properly tuned for WOT it will run perfectly at any speed. If it cuts out quickly it's too lean and is also subject to overheating. If it gets blubbery and then sputters and stalls, it's too rich.