Pull start on nitro engines jams with glo plug

Welcome to RCTalk

Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
It could also you have the wrong type of spark plug in, the threads are too long and block the piston movement. Try to loosen it a couple of turn, if it move, then slowly tighten it. You can also take a picture of the glow plug.
 
It could also you have the wrong type of spark plug in, the threads are too long and block the piston movement. Try to loosen it a couple of turn, if it move, then slowly tighten it. You can also take a picture of the glow plug.
Nitro engines don't use spark plugs. They use glow plugs. There is only one length. Other type won't fit turbo plugs. You must be referring to the heat range?
 
Nitro engines don't use spark plugs. They use glow plugs. There is only one length. Other type won't fit turbo plugs. You must be referring to the heat range?
clearing this up, there are two different lengths of glow plugs... Short (typically only found in O.S. engines) and long/standard (there are a few other manufacturers that use short plugs, but not many).
1613946615269.png

1613946769479.png

courtesy of Amain Hobbies from the product description from O.S. Engines
a short plug CAN "work" in a long/standard plug application, but wont be correct and wont right as well as it should.
a long plug CAN'T work in a short plug situation as it will most likely damage it.
 
Last edited:
I'm almost wondering if your OWB is locked up, and not letting go of the starter shaft, so when there is compression it wont let it retract because the spring is no match for the engines compression.
another possibility is it is flooded, but it looks like that already got cleared up. i would return the needle settings to factory to start with. it will be very rich, but should run.
glow plug length is also a possibility, did you make sure you re-installed the copper washer/gasket under the plug? was a new plug installed, or same plug that the engine ran with previously?
 
Nitro engines don't use spark plugs. They use glow plugs. There is only one length. Other type won't fit turbo plugs. You must be referring to the heat range?
Just a slip of the tongue, I do mean glow plugs, no, there are different lengths.
 
Here are some samples that are all different.
IMG_20210221_163400_992.jpg
 
There all the same length. Long plugs. As I said before.
 
No they are not, the difference are quiet significant.
 
Turbo plugs are definitely different in length.
 
Turbo plugs are definitely different in length.
Turbo plug
None of the plugs in your picture are turbo plugs. They are all standard long plugs. All that matters is the thread side.
1613944297793.png
 
Here is the plugs get arranged, the black one is Traxxas, which is longer and the one with the idle bar is even longer. They are not the same length, not sure the standard mean but they are definitely different. I assume the clearance for the smaller engine is smaller, then it could hit the piston.
 
They are all standard long plug and will work in any nitro standard engine. They are all the same length thread side less the washer. Idle bar has nothing to do with the length. Brand has nothing. The glow plug is not the problem.
You can say whatever you want but they are different lengths for sure. A picture is better than a thousand words.
 
You can say whatever you want but they are different lengths for sure. A picture is better than a thousand words.

Your picture shows standard long glow plugs from different manufactures and they are all the same. It doesn't matter if the plug has a idle bar on it or not it will still work in any standard nitro engine. There is plenty of clearance. I have used all these type of plugs in different engines and they all work the same.
 
Your picture shows standard long glow plugs from different manufactures and they are all the same. It doesn't matter if the plug has a idle bar on it or not it will still work in any standard nitro engine. There is plenty of clearance. I have used all these type of plugs in different engines and they all work the same.
You never know if that is the problem with that particular engine. It is one of the variable.
 
If he can turn the engine with the plug in using the flywheel, then it is not the length of the plug, if he can't turn over the engine with the flywheel, then it is very possible.
 
You never know if that is the problem with that particular engine. It is one of the variable.
It's not the problem as the plug is standard long type. The pull starter jams and this could be from????? I suspect the engine is used and has been taken apart and is missing the head shims. Which can cause this partial problem with starting. It dose fire But the starter doesn't recoil back which is the other problem when trying to start. That tells me the starter case is too tight.
 
They are not all long, one of the is an OS #8 which is considered short plug.
 
Back
Top