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engine not starting

Old 04-10-2010, 03:10 PM
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Sherv
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Default engine not starting

when i pull th engine will sputter for 1 to 2 seconds then pop dies. took off the spark plug and was greated to lots of smoke and lots of black oil\residue.
took a pic of the spark plug. think its fouled?
i cant see the spark but i can feel it
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Old 04-10-2010, 04:59 PM
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DarkFire989
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Default RE: engine not starting

That is way too rich. Clean off the plug and lean it a bit.
Old 04-10-2010, 08:52 PM
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Default RE: engine not starting

now if it still wont start turn the truck over with out the plug in it and pull it over kinda fast till no more gas mix comes out. then take either starting fluid or brake cleaner and clean off the plug and then turn you needles in all the way and then try to start it. if it starts make sure you have the truck off the ground bc it will run and it will rev up fast so be ready to shut the engine down with you killl switch then start it again and make sure it dont over rev. and continue that till it wont start anymore then turn your needles out about 1 turn on low and and about 1 1/2 on high and you shouldnt need to choke it but if it dont fire at all go at full throttle and try to start it. hope that helps man. also check out my thread http://www.rcuniverse.com/forum/m_96...tm.htm#9647286 i had the same problem the other day and it flooded and it had the darnest time to get it started. that is what i did ( above ) and it worked for me. hope all this helps you out.

TJ
Old 04-10-2010, 09:06 PM
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SAVAGEJIM
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Default RE: engine not starting


ORIGINAL: Sherv

when i pull th engine will sputter for 1 to 2 seconds then pop dies. took off the spark plug and was greated to lots of smoke and lots of black oil\residue.
took a pic of the spark plug. think its fouled?
i cant see the spark but i can feel it

I unfortunately have to say the plug could be totally gone.
Sometimes, you can clean a fouled plug like that and it will run, but other times, the plug is dead.

Do give that one a cleaning anyway and see if it still will fire, but before you do attempt to fire it up, lean your engine just a tiny bit.
If the plug will fire, once the engine is beginning to run, immediately begin to tune it to where your engine is running nice and smooth at idle.

If you are experiencing this fouling because you go full trigger almost all the time, you will have to lean the high needle to correct the richness.

Of course, as you mentioned that you did in the NGK plug thread, do keep a couple extra plugs in your tool box so if the plug indeed is gone, you can slap in one of the extras and go from there.
Old 04-10-2010, 09:56 PM
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Default RE: engine not starting

Thanks for the suggestions! I forgot to mention after posting this that I did clean the plug and it ran fine idling... I gave it a little throttle and 5ft later it died. I did not tune the carb. I guess tomorrow when I get the new plugs I will lean out the hsp needle a bit. I do go full throttle but not continuously since I run on grass most of the time. I did not lean the engine much because it felt pretty lively/responsive plus because It's my first gasser... Seeing 280F temps made me think twice about tuning. After reading about these engines I understand that temperature is not a very important factor when tuning. The residue on the plug, engine performance, and sound is the correct way to tune. I wonder how much better the performance will be when I tune it right... Because right now with the rich setting it hauls ass.
Old 04-10-2010, 10:29 PM
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Default RE: engine not starting

now if it died when you gave it gas then you LOW speed needle is to rich or too lean. but by the looks of you plug its too rich. your low speed needle effects your acceleration up to about 3/4 for the way to WOT. your high speed needle effects your top speed mainly. to make sure your not too lean run your RC at WOT and then shut it down right after words and take out your plug it should have a light to medium choclate brown to it. if its white to lean if black to rich. you will want the engine to be a lil rich at a idle bc when you give it throttle it will be right where you need it for proformance in you "mid range". the way i set my low speed needle is i started rich but no rich it wouldnt idle. then slowly leaned it out ( 1/16 to 1/8 turns) and you will need to back out the idle screw so it dont idle do high it engages the clutch. continue to lean it out till it boggs when you hit the throttle and then rich it up in little adjustments till it quits bogging out. when the needle is set right it should idle smooth and sound like its four cycleing. (it should make a Dun de dun de dun sound) not a eeeeeeeeeeeeeee sound.... if it is then rich up the low needle till it fireing on every other revolution.... four cycleing making the dun de dun de dun sound. hope that not to confuseing. its kinda hard to put in words how it should sound at a idle.

correct me if im wrong guys. but my Fire hammer runs great and that is the way i did it.

TJ
Old 04-11-2010, 11:48 AM
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Default RE: engine not starting

This is insane... I got fresh fuel 25:1 oil ratio, new spark plug ( i still cant see spark but now the jolt hurts compared to before), cleaned out the tank and flushed out the old fuel. Leaned out the needles and even reset them to factory setting... Same problem. Few days ago it ran fine until I ripped my pull start cord. When I was replacing it I noticed it was pretty easy to spin the crank by fan using the fan... very little compression compared to my nitros... Is it supposed to be that low of a compression? The engine ran perfectly fine since I had the vehicle... Only ran 7 tanks through it and now it just sputters for 1-3 seconds and then stops with a loud pop like its backfiring. Any suggestions? I might take the engine apart soon, anyhting specific I should look for?
Old 04-11-2010, 01:12 PM
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Default RE: engine not starting

Reset the coil gap. The appropriate distance for coil gap is a business card. So stick a card in between the coil and flywheel then re tighten it back up.
Old 04-11-2010, 02:46 PM
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mecano
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Default RE: engine not starting

Sounds like you have low compression, it should be over 100 psi. If not, is probably time for a new top end (piston/ring, if cylinder is not damaged) . Check your air filter too, and make sure is not too wet.
Old 04-11-2010, 02:58 PM
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Sherv
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Default RE: engine not starting

I'm going to do what DarkFire said in a min. If I do have low compression... It doesnt make any sense because the engine was running VERY rich and never exceeded 270F.
The new plug hasnt even been properly used yet and its full of black oil and soot
Old 04-11-2010, 03:45 PM
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goneracing_83
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Default RE: engine not starting

Im with Mecano. if you have low compresstion the engine wont run right or at all. if your coil readjustment dont help check your air filter. if it is to wet or really dirty it wont pull enough air thru the filter there for low compresstion. easy way to see if it is you air filter is to take it off and pull it over and see if there is a differance if so then your filter is plugged. clean the filter and put it back on and you should be ready to go.and you say the plug gets full of black oil and soot.... well sounds to me you have a lot of carbon build up on the top of the piston. that is from using cheaper 2 cycle oil and running it rich.
Old 04-11-2010, 03:54 PM
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Default RE: engine not starting

what type of oil did you mix with your gas? a 2 stroke gas will run kinda with low compression, it will have no bottom end power tho. is it possible theres any air leaks around your carb?
Old 04-11-2010, 04:04 PM
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Sherv
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Default RE: engine not starting

I used havoline 2 stroke oil from auto zone. 25:1-20:1 ratio. I did notice a lot of dirt was stuck on the outside of the carb. IT is possible that it stuck because it was wet from a leak. I am about to check the gap that darkfire mentioned in a few min.
Old 04-13-2010, 02:12 AM
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Sherv
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Default RE: engine not starting

problem solved. remote kill switch for some reason was touching the coolin head and one fin had melted enough to expose and touch/short the wire. i thin a flip must have caused it because i had zip tied it to the top of the roll cage. engine is running lean now. trying to richen it but ran out of time. thank you all for your advice as it will help me in the future when i trouble shoot new problems. much appreciated!

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