Not sure if i have a gearbox or engine problem?

[martin34]

Hi guys i wasnt sure where to post this as i am not sure about my problem.I was running my XL last sunday with about a gallon and a half through it when it started to loose topend.The tune was good.It then didnt want to wheelie so i thought maybe i was stuck in second but cant have been because the engine would be screaming at the topend if it was.I bought the xl back and i gunned the throttle to see what would happen.It pulled away about a foot but then it started to sort of stutter(hard to explain)i was giving it full throttle but it was like i was full throttle then no throttle,smoke then no smoke without it realy picking up any speed.I am going to strip it down this weekend but has anyone got any ideas as to weather it mite be the gearbox or engine?I hope this has made a bit of sense?

 

[frddyj]

try tightening down the slipper nut that holds the spring onto your spur gear. sounds like it couldve loosened up on ya.

 

[NITROMITE]

is your glow plug good? this sort of stuff happens when you tost a plug, i would check it first, then if its good did you lean the lsn? if soo you may have went too far bring it back a bit and see if that helps.

 

[Hypnotiq]

same thing happened to me tuesday night..

check to see if your spur does this..

http://www.youtube.com/watch?v=__tJJEOOquw

 

[Pope]

If your motor gets to hot this happens too.

 

[Londoner]

The spur nut kept backing off on my pals 25 a few weeks ago, even if i tightened it right up it would back off and slip like crazy before it would even get to second gear, put a new nut on and problem solved.

 

[martin34]

Thanks for the quick replys.I have just had the gearbox apart and all the gears look ok.No ware at all.Checked the slipper nut and it is tight and it doesnt spin as in the vid.There does seem to be alot of oily fuel on the bottom of the engine.Could that mean anything?

 

[Pope]

could be a leaking front bearing.

 

[martin34]

could be a leaking front bearing.

Thanks.If it was leaking would it make it run like i tried to describe?

 

[NITROMITE]

Thanks.If it was leaking would it make it run like i tried to describe?

i don't think so did you replace the glow plug?

 

[AllanQ]

Sounds like a tuning problem to me. When you say "stutter" does that mean it sounds like a 1:1 car engine hitting a rev limiter, or does it appear to be gurgling. IMO, based on what you said earlier about oil, my guess is its a gurgling sound and you are rich on the HSN causing the extra oil to come out of the front.

 

[NITROMITE]

Sounds like a tuning problem to me. When you say "stutter" does that mean it sounds like a 1:1 car engine hitting a rev limiter, or does it appear to be gurgling. IMO, based on what you said earlier about oil, my guess is its a gurgling sound and you are rich on the HSN causing the extra oil to come out of the front.

good call allen i thought meybe the lsn but it could very well br the hsn

 

[martin34]

I haven't replaced the glow plug but have checked it and it looks good.I think the tune was ok.It was running fine for a few tanks(on sunday)before it started to do this.Temps were around 220f(on my temp gun anyhow.My mates and mine all give different readings).Maybe i should go back to factory and re tune again and see what happens?The best way i can think of describing it again is it was as if i was riding a motorbike and flipping the kill switch on and off(without the bang of course lol).

 

[NITROMITE]

it sounds more and more like the GP to me i found out the hard way i kept tuning and tuning nothing seemed to work so i put a new GP in and off she went. this may not be whats wrong with yours but its simple and all nitro guys keep extras any way so throw one in and see what happens if thats not it at least you eliminated one thing and can go from their.. keep us posted and we will eventually figure it out.

 

[martin34]

Thanks i will give a new Glow plug a try as soon as i get it back together and let you know how i get on.