nitro rc not starting

[xerrr]

Hello, i currently have a hobao hyper 7.5 and I'm having trouble starting it.

Things i’ve done
checked carb
factory settings
new glow plug and new glow igniter
put nitro directly in the carb and directly into the piston to no avail
checked fuel is going to the carb
heated the engine

help?

 

[332_RC]

Welcome to RCT! This group here on RC Talk will help you out!

 

[Beer_Goggles_RC]

Welcome to rct!

Any bubbles in the fuel tubing?
What temp did you heat the engine to?
Hows the pinch?
Have you checked all your exhaust gaskets and fuel tank gasket?

Pull, roto, or bump start?

 

[xerrr]

thanks, and yes there are 1-2 bubbles in the fuel tubing. i used a hair dryer on max for about 5 minutes directly on the cooling head and the block around it. my exhaust gaskets and fuel tank gaskets are good i’m assuming because i am able to prime it by putting my finger on the exhaust and pulling the pull rope. i am using a pull rope.

Welcome to rct!

Any bubbles in the fuel tubing?
What temp did you heat the engine to?
Hows the pinch?
Have you checked all your exhaust gaskets and fuel tank gasket?

Pull, roto, or bump start?

 

[Beer_Goggles_RC]

thanks, and yes there are 1-2 bubbles in the fuel tubing. i used a hair dryer on max for about 5 minutes directly on the cooling head and the block around it. my exhaust gaskets and fuel tank gaskets are good i’m assuming because i am able to prime it by putting my finger on the exhaust and pulling the pull rope. i am using a pull rope.

Large bubbles or just little bitty bubbles? Bubbles in the fuel line can indicate inadequate back pressure on the fuel tank. Hair dryer for 5 minutes should get it warm enough. Pull starts can be a major pain when they don’t wanna start lol.

What’s your weather like? I’ve had trouble starting in cool weather and usually have to do a bit extra heating

 

[xerrr]

Large bubbles or just little bitty bubbles? Bubbles in the fuel line can indicate inadequate back pressure on the fuel tank. Hair dryer for 5 minutes should get it warm enough. Pull starts can be a major pain when they don’t wanna start lol.

What’s your weather like? I’ve had trouble starting in cool weather and usually have to do a bit extra heating

their just tiny little bubbles but they go away. it’s 83 right now and i’m in texas so it doesn’t get that cold lol.

 

[Beer_Goggles_RC]

their just tiny little bubbles but they go away. it’s 83 right now and i’m in texas so it doesn’t get that cold lol.

as long as compression is good you might just have to heat it up and crank the hell out of it. Try giving it a little bit of throttle on and off. I’m assuming you’ve ran this rc before and it’s just been a while since it last ran?

 

[xerrr]

as long as compression is good you might just have to heat it up and crank the hell out of it. Try giving it a little bit of throttle on and off. I’m assuming you’ve ran this rc before and it’s just been a while since it last ran?

yeah, it was a gift for my birthday from my uncle and he had ran it before but it just hasn’t ran in 4-5 years. how do u know if u have good compression? the pull start feels like it has compression, almost like notches

 

[Beer_Goggles_RC]

yeah, it was a gift for my birthday from my uncle and he had ran it before but it just hasn’t ran in 4-5 years. how do u know if u have good compression? the pull start feels like it has compression, almost like notches

The engine probably makes 4 or 5 revolutions per pull so that should be the notches you’re feeling. If you can feel some resistance through the pull start then you’ve probably got enough compression for it to run.

Get it as hot as you can with that hair dryer without melting anything. Take care to keep the heat off the carb. Then just sit there and give it hell and play with the throttle while you’re cranking. ~1/4-1/2 throttle is usually the money. Could take up to 10 minutes.

If you still can’t get it started I’m sure your local hobby shop would be happy to give the engine a quick look over and help you get it started.

Maybe check your idle gap too. Aim for 0.8mm a standard sized paper clip is usually .8mm

 

[TeknoJ]

You need a temp gun. Get the cooling head to about 115 and short quick pulls. Make sure the exhaust gasket at the header/manifold is good, it tends to breathe in and out when leaking. You may need a new glow plug if it has been sitting. Make sure the igniter is fully charged, mine gets weak and won’t ignite the plug after I have been pulling the crap out of it. Prime the carb by plugging the exhaust like you have mentioned, just don’t over do it. As soon as it gets right to the carb it should be good.
Start with some on line learning:

If there’s anything else we are here for you!

Also, what fuel are you using??

 

[Greywolf74]

Since it sat for 4-5 years, you may have gummed up fuel inside the carb. If remove the carb and soak it in nitro fuel for a couple of days to clean out any possible clogs.

Since you're getting fuel to the carb, you've replaced the glow plug and igniter, it's almost got to be a problem of the fuel/air not getting through the carb into the engine, I would think.