hamradioguy Posted March 5, 2021 Share Posted March 5, 2021 He has already said that he put some petrol down the plug hole and it didn't fire up, if that's true then its nothing to do with the carb/settings because as I said you can take the carb off and it will still start and run for a second or two if you put petrol straight in to the cylinder. Quote Link to comment Share on other sites More sharing options...
SeagullMan Posted March 5, 2021 Author Share Posted March 5, 2021 I dont get the pop, it doesn’t sound like it’s trying to start at all Quote Link to comment Share on other sites More sharing options...
spents Posted March 5, 2021 Share Posted March 5, 2021 (edited) 7 hours ago, hamradioguy said: He has already said that he put some petrol down the plug hole and it didn't fire up, if that's true then its nothing to do with the carb/settings because as I said you can take the carb off and it will still start and run for a second or two if you put petrol straight in to the cylinder. yes mate, but an engine also needs air to run, if he has the carb on there and puts fuel in the plug hole then it still aint getting air if the butterflys closed too far so it can run, and yes i know a two stroke will run without a carb on for a few seconds as long as theres fuel in the case/cylinder and its getting air cos theres no carb on, but as far as i can tell he aint tried without the carb, i've just been through this myself as stated in my last post, literally last week with a brand new engine, idle to low and it does the exact same thing as op says, pops on and off choke but wont run, i've been into petrol rc for over 30 years by the way, i di have experience , only trying to help the dude, edit, just re read the whole thread, i had it in my head that it did pop, just seen thats not the case, my bad lol, well it sounds more spark orientated then, you did check the coil gap didnt you ? just to make sure the coils not dragging on the flywheel i mean, plus check the spring wire in the plug cap, make sure its actually going onto the plug when you push the cap on, they do move and pull out sometimes, Edited March 5, 2021 by spents my bad lol, Quote Link to comment Share on other sites More sharing options...
hamradioguy Posted March 5, 2021 Share Posted March 5, 2021 1 hour ago, spents said: yes mate, but an engine also needs air to run, if he has the carb on there and puts fuel in the plug hole then it still aint getting air if the butterflys closed too far so it can run, He did say "Throttle butterfly has a slight gap at the bottom for air it seems and I've tried to start with choke on and off but no luck, also tried it with throttle open a bit more" Quote Link to comment Share on other sites More sharing options...
Bruce Larsen jr Posted May 16, 2021 Share Posted May 16, 2021 On 26/02/2021 at 12:03, Mack1 said: Yes that's the correct procedure. It's a long shot you could take the carb off and check that the gasket is the correct way around as it has a small hole in it that should align with the pulse holes in the carb and manifold. Did you every get it started. I am having same problem Quote Link to comment Share on other sites More sharing options...
Mack1 Posted May 16, 2021 Share Posted May 16, 2021 3 hours ago, Bruce Larsen jr said: Did you every get it started. I am having same problem I'm not sure if the OP ever got it going again. Certainly not seen any posting to say anything has worked. But I know from experience the last couple of times I have had a complete no start every time it has been a head gasket that has blown, a common problem on a 2 bolt cylinder head. Quote Link to comment Share on other sites More sharing options...
SeagullMan Posted July 17, 2021 Author Share Posted July 17, 2021 Been a while, Truck still wont start, I gave up after a while but now I'm ready to try again with it, don't really fancy ordering a brand new engine just yet, I've ordered a set of gaskets to ensure they aren't the problem Quote Link to comment Share on other sites More sharing options...
Nitroholic Posted July 17, 2021 Share Posted July 17, 2021 This is a simple 2 stroke single cylinder engine.....so ....as with all such, it just needs 3 things to run. 1) Fuel 2) Compression 3) Spark Get all those things, and your engine will fire. 1) Fuel. Well..you have tried adding a few drops directly to the cylinder, and it won;t even try to fire. If you are pumping enough fuel around the carb via the priming bulb and using a good starting technique...then it should go.... but it doesn;t. My starting routine... prime....choke on....pull 2 or 3 times and the engine should 'cough' .,... choke off...pull and it should fire. 2) Compression. Well...it's not easy to measure.....but if you got the plug out and it feels the same as the plug in... No...seriously, you can get all sorts of wear, busted rings, blown gaskets...andthat can mess with firing up. 3) The most regular culprit....spark. Kill switch issues, poorly adjusted coil, failed coil.... I bought a new KM Baja from RCModelz that came with a dead coil from new. They swapped it no bother, as I could easily demonsrtate the failed unit as I had a spare which I swapped in and the motor fired just fine. Easy to check...just take out hte spark plug, clip it back into the plug lead...hold the electrode on something metal on the engine and pull the pullstart. If you see a nice clean spark...you have ignition. See no spark....and you have your problem. Quote Link to comment Share on other sites More sharing options...
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