CDI shutdown

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Basher72

Basher72

Member
Messages
18
I got an Octane day before yesterday in a trade, thought I wanted gas, not so much now. I have scanned the forums and do not see this exact problem. Truck starts easy, runs ok, with the exception of the transmission not shifting. The transmission problem will wait. Truck runs 4 to 6 minutes and shuts off and will not restart. I am an auto tech so I know basic engine diagnosis. I pulled the plug and checked for spark and had non, let it cool for 5 minutes bam its back and starts right up. I replaced the CDI module with a known good unit, does the same thing. It has plenty of compression when heated up, no fuel problems, and plug looks brand new and clean. The only thing I can come with is the crank sensor. Anyone else have this problem before or have any ideas?
 
F-Type said:
Still, try a different plug. Swap plug directly after it stops, and see if it won't start up right away again.
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Ok I will that thanks. The NGK 5812 shows the same specs as the HPI plug, and it's a forth the cost. Will it work?
 
Hi, I have a similar problem (runs and then stops, wait 10 minutes and then all good, only to be repeated again) here in Hungry with temperatures currently up at 34-37 degrees centigrade. Is the ambient temperature a factor ? My truck is also new (Version 1) and I have now gone through 3 tanks in the running-in phase (my gearbox is also not changing up, but am less worried about this for the time being). Any help would be appreciated.
 
Carl Forte said:
Hi, I have a similar problem (runs and then stops, wait 10 minutes and then all good, only to be repeated again) here in Hungry with temperatures currently up at 34-37 degrees centigrade. Is the ambient temperature a factor ? My truck is also new (Version 1) and I have now gone through 3 tanks in the running-in phase (my gearbox is also not changing up, but am less worried about this for the time being). Any help would be appreciated.
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I believe the Octane usually requires a large amount of break in. You'll likely have to be fairly patient for your engine to run well. This also affects your shifting. If the engine cannot get the RPMs up to a suitable range it will not shift and if the engine is not running well it will not do that.
 
Ok I contacted Great Planes (HPI) support yesterday. First thing they said was the engine was worn out and losing compression. I assured them this was not the case, that it is losing fire to the plug. They are sending me a new crank senor, and if that doesn't work a new CDI box.
 
I would suggest your engine is getting too hot. If you have leaned it at all take it out. If not richen it 1/2 of an hour on the HSN. The Octane engine has a ringed piston and too much heat makes it lose compression. It is easy to tell this when you pull the starter.
 
francis Labarbara said:
I would suggest your engine is getting too hot. If you have leaned it at all take it out. If not richen it 1/2 of an hour on the HSN. The Octane engine has a ringed piston and too much heat makes it lose compression. It is easy to tell this when you pull the starter.
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Put the carb back to factory specs and see if that helps. My octane did not start shifting to the 6th tank
 
It running cool it's not overheating. The CDI shuts off just like you flipped the switch. The truck only has like 5 or 6 tanks through it. I didn't lean it out at all. It's at factory settings now.
 
Are you using the original batteries? You might want to change the magnet to the cdi or make sure it is aligned to thr right spot
 
Pulled the crank sensor today was really dirty for the engine to be so new. Has a bad spot on the plastic. New one shipped yesterday. I will post an update when try it. The batteries are new by the way.
 
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X said:
I believe the Octane usually requires a large amount of break in. You'll likely have to be fairly patient for your engine to run well. This also affects your shifting. If the engine cannot get the RPMs up to a suitable range it will not shift and if the engine is not running well it will not do that.
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Thank you for your help. Presumably a higher ambient temperature is going to extend the running-in phase?
 
I broke my octane in by running it at 1/4 throttle the first two tanks. Then the next two tanks I went back and forth between 1/4 and 1/2 throttle. I continue that to the sixth tank. That's when I noticed it started running better. That's when I started using full throttle. I only did a tank a day. I have not had any motor problems. There is a video on YouTube about how to do it. I'll look for it and post it here.
 
Looks like the same video as above and sorry to say the guy does not even know a choke from a chock if ya ask me..... not too awfully useful to be honest about it......
 
Just wanted to update ya'll. It was the crank sensor. Got delivered yesterday and installed it today. Ran two full tanks through it with no problems. Thanks for all the advice.
 
Great to hear you got it working! And thanks for the update! Good to know. It's the first time I hear the crank sensor to be the issue!

I did suspect mine for a while, but in the end it turned out to be compression issues, crappy manufacturing.
 
Yeah I think it's either getting converted to nitro or electric or getting sold before the compression thing becomes an issue.
 
Mark Walters said:
How new is this octane
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Maybe 6 months old it sat a buddies house without any action till I talked him out of it. Tank three sensor goes bad, go figure. I should known better I got bit by the Losi gas buggy and truggy too. But I thought this one is ringed and has a Webro carb so It will be better. Not so much. I have two 5.9xl's that I'm very happy with. This one is in a trade for a fifth scale gasser as we speak.
 
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