FMX 650 Tuning

[tractot4play]

Im sure it does but on a very small scale and you wont notice it, i doubt it runs cooler though, its mainly a tidying up excercise plus it stops crappy exhaust gasses gong back into the airbox. They do this for the US enviromental restrictions on all vehicals but there is no test on a UK MOT for emisions so its doing nothing.

regards

ill ask yourself considering you started this thread do you have any info on replacing the single head with a dual carb head.i know the head bolts and dowels are different which is not a problem.the camchains are a different width so can i swap cam sprockets from the 600 to 650.i have a 600lm stripped to swap the kicker and countershaft over and all seems straight forward apart from the camchain gear.i would be grateful for any info or help.T.

[lee fmx]

oi oi fella's i got my 05 fmx a few days ago it came with k&n and full arrow system ready fitted iv had the baffles out and today removed the smog filter and drilled the airbox. it seems to have abit of a flat spot at low to mid revs. would a stage 2 dyno kit cure this ?? and what exactly is involved in fitting and setting up the dyno kit ?? is it something i (a novice) could do or is it a job for a proper mechanic ?? L££

[switch]

oi oi fella's i got my 05 fmx a few days ago it came with k&n and full arrow system ready fitted iv had the baffles out and today removed the smog filter and drilled the airbox. it seems to have abit of a flat spot at low to mid revs. would a stage 2 dyno kit cure this ?? and what exactly is involved in fitting and setting up the dyno kit ?? is it something i (a novice) could do or is it a job for a proper mechanic ?? L££

For the price of a dyno-jet stage 2 you can probably get the bike properly set up at a dyno-shop by a proper mechanic.

[futter]

hi futter,did you use the xr barrel also or just use the xr wiseco piston?i know the standard bore and stroke are different in each motor so did this have any effect.i would be grateful for any details.regards ian.

Nope - the standard SLR barrel takes the 628cc Wiseco piston as a straight fit (100mm if memory serves) it has a 2mm longer stroke (I think) than the XR600.

The HRC cam is a a straight fit as well. Can't for the life of me remember the name of the HRC dealer. I do know a chap who would know though. Will ask if you want. Failing that Paul at Worthing Motorcycles is pretty knowledgable with all things XR - ooh ooh ooh - name of HRC dealer might be Vic Eastwood? Yup it is. He also appears to do Wiseco etc so can prob be of lots of help.

[zippychips]

Nope - the standard SLR barrel takes the 628cc Wiseco piston as a straight fit (100mm if memory serves) it has a 2mm longer stroke (I think) than the XR600.

The HRC cam is a a straight fit as well. Can't for the life of me remember the name of the HRC dealer. I do know a chap who would know though. Will ask if you want. Failing that Paul at Worthing Motorcycles is pretty knowledgable with all things XR - ooh ooh ooh - name of HRC dealer might be Vic Eastwood? Yup it is. He also appears to do Wiseco etc so can prob be of lots of help.

Padgetts of Batley in Yorkshire are a HRC dealer......hope youve got BIG pockets!!! lol

[futter]

Padgetts of Batley in Yorkshire are a HRC dealer......hope youve got BIG pockets!!! lol

Depends how far you wana go really - piston and cam, with a bit of head work and a decent carb/exhaust wont break the bank.

My SLR had a standard carb, stainless custom exhaust, cam and piston.

[gpzDave]

My SLR had a standard carb, stainless custom exhaust, cam and piston.

How much difference was there after you fitted that stuff?

[futter]

How much difference was there after you fitted that stuff?

By the time I have fiited the system/cam/piston and had some dyno time it was 43bhp at the wheel rather than the standard 39bhp at the crank.

Here it is.

[gpzDave]

By the time I have fiited the system/cam/piston and had some dyno time it was 43bhp at the wheel rather than the standard 39bhp at the crank.

Here it is.

That is awesome! I really like what youve done to it, much more agressive looking. And thats a good power increase aswell, prob 10hp(+/-).

[futter]

That is awesome! I really like what youve done to it, much more agressive looking. And thats a good power increase aswell, prob 10hp(+/-).

Thanks - sold it ages ago though - spec is:

SLR with engine mods as stated
JMC swingarm
KR1S rear wheel/brakes
TZR125 front wheel/disc and SLR caliper
CR500 forks/yokes
9mm shorter tiebar (to jack it up)
Hebo headlight
Stainless brake hoses etc
The exhaust was a one off made by a guy local to me, stainless steel throughout and £275 all in!

Sold it for an XR600 with HRC kit fitted, cam, carb, pipe, ported/flowed, ohlins etc - that was 47bhp at the wheel but a massive torque curve/line on it - would wheelie in 3rd gear off the throttle no problem.