Topic: urgent help !!

[merlin69]

anyone know which year and model XL125 pistons fit the 500/4 im building a race bike for the manx gp
Thanks Dave

[DavePhipps]

PM turboguzzi, I think he has that answer. Or just poke through his threads. I think the answer is in there somewhere.

[turboguzzi]

Gee dave

we all see that you are in a hurry but a little friendly introduction with pics of your build will be appreciated and make people more sympathetic with your valiant effort .

It will yield more response too, so well worth the extra five minutes attention you give us

in any case, i haven't used xl125 pistons in my build (long story) but have a friend who does so with success and gave me one to measure

it's off a late 70's to early 80's XL125S or XL125R, doesnt really matter as they are the same piston

you will have to turn it down a bit, dome is too high
 
You welcome!

TG

[lordmoonpie]

Hey TG - I suggested Dave joined here to get help, he's up against it to get his bike built for the Manx so kicking back and chewing the fat is understandably not as much as a priority as it is for us old timers. There's the makings of a great HiPo thread here - from build to Manx GP so it'd be great if Dave can access everyone's experiences on the 500/4 to help him realise the goal of being on that Isle of Man start line. 

How about giving us some of that long story TG - what pistons are you using then?

[turboguzzi]

Hey TG - I suggested Dave joined here to get help, he's up against it to get his bike built for the Manx so kicking back and chewing the fat is understandably not as much as a priority as it is for us old timers. There's the makings of a great HiPo thread here - from build to Manx GP so it'd be great if Dave can access everyone's experiences on the 500/4 to help him realise the goal of being on that Isle of Man start line.  

How about giving us some of that long story TG - what pistons are you using then?

Sure my lord,

i am using ultra low monkey bike 57mm kit pistons and  the story is long because these required so much milling of the cyl block that i lost chain tension, had to go with a CBR600 tensioner implant.... not the kind of thing you want to do in a hurry

read about it here
http://forums.sohc4.net/index.php?topic=55162.0

seeing how reliable/fast some mate's bikes are with stock rods and modified XL125 pistons, nowadays i dont think it was worth the trouble, was a fun project though. still cant believe it works so well

In any case, good luck with your build dave, and post some info when you have the time

TG

ps dont forget to deepen the valve pockets!