Help with starting Hyper 7 TQ (21 mac engine)

[Bound]

Hello

 

I can't start my Hyper engine. It did run previously with the pull start attached untill it broke. 

 

Haven't changed needle settings or anything since then. The carb is set open about 1mm. Fuel is getting to the carb and the glow plug is heating up but it won't start. 

 

I've attached a video for how it sounds etc. 

 

https://vimeo.com/279709116

 

Cheers

 

Rich

[Jimmer7even]

Take plug out turn engine over until you see fuel spitting.put plug in try again,piston sounds dry on vid

[Ian w]

Looking at your video it don`t look like you have the glow plug heater on right. It should clip on and stay on.  

[sunny]

I don't do nitro but this may help:

 

https://www.rctech.net/forum/offroad-nitro-engine-forum/465032-rc-nitro-troubleshooting-flowing-chart.html

[Nitroholic]

Few things here ....

 

1) Did you prime the motor? You need to or you can get an airlock that stops fuel flow. Always worth checking fuel is flowing

2) That glow plug heater should be vertical. Not at an angle. If it is not making contact with the centre pin of hte glowplug, it won't glow

 

Also, have you checked the glowplug is actually working. Take it out and po pit in the heater. It should glow nice and bright.

 

Lastly...you really shouldn't crank it that long on the drill starter. If it is not firing, don't keep flogging it. You really are not doing hte motor any favours that way. If the fuel isn;t flowing, the one way bearing in the rear will be running dry and will wear out quickly. As will all the other parts of your engine. Drills also supply a lot more torque....make sure you use a screwdriver setting with low torque. If your motor hydro locks or has a problem ..... you want the drill to stop not force the piston round.

[Bound]

Thank you to everyone for your replies. 

 

When I take the plug out it doesn't seem wet. Engine doesn't lock up but there always seems to be fuel in the exhaust pipe. 

 

The actual fuel lines don't seem blocked, I've blown down them etc and can see it flow to the carb.. Also tried swapping the lines for shorter ones to try to get maximum pressure. 

 

I'm using a 14.4 Bosch professional drill to start the engine on 2 speed.. Is it not quick enough to turn over the engine? Is a pull start or proper roto start hand starter quicker? 

 

Essex area if anyone's local!

 

Thanks everyone. 

[Nitroholic]

The drill speed is not an issue.....just drill cranking a motor for too long is not a good thing to do. Proper rotostart units do not have a lot of torque and will stop before harming an engine if it hydro locks. A drill won't. It has torque designed to force a drill bit through hard materials. My DeWalt is rated at around 60Nm of torque....which would wreck a piston and bend a conrod. But that's by the by....and not related to your non starting issue.

Back to that

 

While you have the plug out......put it on the glow starter. See how bright the glow is. That will confirm if the plug is good or not. Glowplug filaments can fail without physical failure. They get coated and simply stop glowing well. That would rule out plug issue...and glow igniter issues.

 

Assuming you have compression ( turn the flywheel through TDC and feel the pinch.... ) then most likely it's a fuel issue. Don't put that plug back in just yet.

 

Priming the motor by blowing down the tube that normally goes to the exhaust is getting fuel flowing up the pipe to the carb. While doing that....open the throttle. You should feel the pressure drop and see more fuel flow. This puts fuel into the motor. If it doesn't...your crab needs a clean out!

 

Turn the car upside down and spin the motor over on the drill start. Some fuel should come out of the plug hole. Plug back in...start it up.

 

But if your drill has a screwdriver torque setting...turn it right down to the lowest. You want the clutch to disengage if anything stops the motor spinning freely. Also.....do not crank it for too long. It should fire up fairly quickly...or not at all.

[Bound]

On 14/07/2018 at 14:05, Nitroholic said:

The drill speed is not an issue.....just drill cranking a motor for too long is not a good thing to do. Proper rotostart units do not have a lot of torque and will stop before harming an engine if it hydro locks. A drill won't. It has torque designed to force a drill bit through hard materials. My DeWalt is rated at around 60Nm of torque....which would wreck a piston and bend a conrod. But that's by the by....and not related to your non starting issue.

Back to that

 

While you have the plug out......put it on the glow starter. See how bright the glow is. That will confirm if the plug is good or not. Glowplug filaments can fail without physical failure. They get coated and simply stop glowing well. That would rule out plug issue...and glow igniter issues.

 

Assuming you have compression ( turn the flywheel through TDC and feel the pinch.... ) then most likely it's a fuel issue. Don't put that plug back in just yet.

 

Priming the motor by blowing down the tube that normally goes to the exhaust is getting fuel flowing up the pipe to the carb. While doing that....open the throttle. You should feel the pressure drop and see more fuel flow. This puts fuel into the motor. If it doesn't...your crab needs a clean out!

 

Turn the car upside down and spin the motor over on the drill start. Some fuel should come out of the plug hole. Plug back in...start it up.

 

But if your drill has a screwdriver torque setting...turn it right down to the lowest. You want the clutch to disengage if anything stops the motor spinning freely. Also.....do not crank it for too long. It should fire up fairly quickly...or not at all.

 

Thought I'd update you as you've been helpful. 

 

So I gave up and took it to a model shop, they did replace the glow plug and lengthened the fuel line between the  tank and carb (it just looks like a connecting piece to extend the line, apperently to help pressure, which is strange I'd have thought shorter lines = more pressure. Additionally they told me the drill wasn't spinning fast enough so bought a roto start. So all in a roto start and a glow plug (the old one WAS glowing but apparently not hot enough. 

 

It starts at the drop of a dime now, first time. Feel a bit vindicated the set up was 99% correct! First thing I will replace from now on is glow plug. 

 

Thanks for all your help. 

Edited August 4, 2018 by Bound

[Nitroholic]

Glad you got it sorted

 

This hobby is all about learning and having fun while you do it. Nitro is a rewarding thing as it takes a bit of effort to make a car run sweetly, and when it does...you get that feeling that says 'I did that'.

 

The longer fuel line won't give more pressure....but what it will do is give more even fuel delivery. Your fuel tank is pressurised by the exhaust, so effectively that is a pressure pulse every bang. A longer pipe will damp that out, plus give a better 'head' of fuel when starting. Priming fills up the pipe, and the fuel in the pipe will give you enough run time to build tank pressure and get more fuel flowing. Incidentally...if you roll the car and it stops upside down...a longer pipe keeps the engine running longer while you turn it back over. The fuel pickup is at the bottom of the tank...so it can run off the fuel in the pipe.

 

Glowplugs...yeah...they do that always have a couple of spares as they can have issues. Especially when breaking in an engine, or when getting used to tuning.

 

Can be frustrating when you first start...and I had to learn a lot of lessons the hard way and got a lot of advice from the old hands. More than happy to pass on what I learnt.