spark plug coming loose?

[bclapham]

Got the first ride on this rm144 last weekend, after the first practise, i noticed the plug had come loose. i tightened it down again, but went to work on the bike last night and it must have come loose again after the second session! :eek:

i remember there was a thread on this ages ago, but even with the search working i cant find it.

let me know your ideas, i dont think its detonating since the bike is running rich and i havent heard it- i think i will see if it happens again this weekend and then take the head of to check for detonation damage. With all these RM plug issues, i am a bit nervous!

cheers

Bruce

 

[steve125]

Bruce an engine can still detonate without you hearing it. Sounds like you have that problem. Marcus says you're too big a load there mate :)

 

[bclapham]

Thanks steve, i think i will richen up the main and put in a new plug to be on the safe side whilst it get the other circuits dialed. After coming off the 250 that pulls most tracks in 3rd all the way, i was really revving the nuts out of this bike and not using enough gears.

thanks

 

[Glitch]

Quick question, why would detonation cause the plug to come loose? Does detonation cause extra vibration?
Thanks
Jim

 

[steve125]

Glitch, the shock wave from detonation, besides eating up the piston and head, can loosen plugs. Just like any excessive vibration does to a regular bolt.

 

[bclapham]

2 sizes up on the main andd problem fixed. still mega rich on the pilot and needle though, whoever had the "rulebook" that said these 144's need leaner mains and fatter pilots needs to chuck it out, LOL!:)

 

[Studboy]

Bclapham is ALWAYS the exception to the rulebook when it comes to jetting.

Or, maybe he just runs the wrong jets because it makes him feel special!!! (Or maybe what Steve125 says is true,  and he puts more load on the motor at full throttle than most 125 riders.....LOL.)

 ;) ;) ;)

 

:p