Engine Problems

[andeep]

hi there I'm a Newbie on this site and this is my first post, i have had a nitro buggy for a while now and crashed it having to replace a few bits, since i am haveing trouble tuning my engine, i have looked at the flow chart in this forum however i only have a one needle set up on my engine, i was wondering if you guys had some tips. i can start the engine up but it is very erratic, it'll work fine 1 min and then the next will keep cutting out or wont start. i was wondering if anyone had a guide on how to tune a 1 speed needle engine thanks. also how many turns should my needle be open. thanks

 

[Metalhead Matt]

You need to make sure you don't have any leaks. Especially after a crash. Erratic tuning is a sure sign of an air leak. The search function will yield you a lot of information on sealing engines. It should take minimal movement of the needles to tune from day to day, or weather changes. Usually no more than a half turn on the hsn. 1/4 turn on the lsn. Every engine is different though, even those made by the same manufacturer. You need to give a little more info too. What kind of vehicle, fuel type and age, glow plug age, ignitor type, ect... The more info you give, the better people can help you.

 

[olds97_lss]

With a single needle carb, you have to tune it rich on the bottom end or it will be too lean on the top. I've only had one that was a single needle, but if I didn't tune it that way, it would get hot quick and shut down. Which is what sounds like your issue is.

 

[Scrogg]

+1 to what olds said. Also check out your clutch and clutch bearings. If a bearing or spring is bad it will stall and run hot. Single needle carbs are the worst thing ever made for nitro engines. You have to have a LSN to tune a engine properly.

 

[andeep]

hi thanks guys for the first bit of info i am pretty sure there are no leaks, i think it sound more like what olds said, the engine does start up but struggle to idle if i increase amount of air intake and it starts to settle but the problem is then the wheels start to move, if i decrease the air intake at idle then the engine cuts out again, however when the engine is running if i accelerate it does cut out hence why i think i may be running a tad on the lean side, how mnay turns open should my needle be open thanks in advance

 

[KryptoRoxx]

That depends on the engine honestly. I have a Novarossi that is a single needle but I never had a problem tuning it. The way I did it was basically clockwise closes the screw so you're either making less air for the engine or less fuel coming through. There is a happy medium somewhere in there. It sounds like you're almost there. If you make adjustments make small ones. It'll get there. Also if you want your wheels to stop moving then you can increase the stiffness of your clutch springs. The stiffer they are the higher the rpm it takes to engage them. Hope this helps. I'm still rather new to this myself and good luck.