XL250 Motosport - Performance ideas/help

[MX?]

OK, sorry to bore you all with this............but.
Looking for tips on the above, and hoping someone here may have some more specifics.
I want to keep the reliability but bump up the pony's a bit...... not looking for outright super performance.
So I spoke to Serco today about getting my 305 kit fitted, which is all good, but they don't have anything to do with cams any more.
They suggested Tighe or Waggott's for a re-grind of the cam and/or line bore to clean up the bushes any recomendations here? or other suggestions
Wanted to stick with standard type carb ( maybe upgrade to a 350 carb?)
What about valves, rockers etc? Is it really worth changing over the valves (different material or oversize)
Any and all ideas invited. 

[lc4]

Do a search on Powroll I think they do or done a bore and stroke kit that would take the Xl out towards 400cc

[matcho mick]

grovel before the Griffith boys,bit of luck they might give you some tips ,

[cyclegod]

Page #23 performance don't come cheap...

http://www.megacyclecams.com/catalog/catalog.pdf

[MX?]

Thanks for the replies. Spoke to Tighe Cams the other day...$170 to weld and re-grind the cam. Serco want around the same to fit liner and bore for the 305. Holiday down here tomorrow, so I'll try and get hold of Waggotts then. Sounds like it all depends on how wild the cam is, as to what other bits need upgrading? Hoping to get away with the bare minimum for a reasonable gain.........though I guess that'll go down the drain once the head comes off.

[jack82]

Thanks for the replies. Spoke to Tighe Cams the other day...$170 to weld and re-grind the cam. Serco want around the same to fit liner and bore for the 305. Holiday down here tomorrow, so I'll try and get hold of Waggotts then. Sounds like it all depends on how wild the cam is, as to what other bits need upgrading? Hoping to get away with the bare minimum for a reasonable gain.........though I guess that'll go down the drain once the head comes off.

Keen to see how you get on with this as I've just picked up a shitbox in need of some serious lovin.I've been scouring the net looking for XL related stuff. So far I've seen 270 and 305 kits......and XLints high comp pistons and 298 kits.Unsure of which way to go but I'm tempted to try a high comp piston just to keep costs down. Any tips,contacts,parts suppliers etc for my rebuild much appreciated.

Checked out your thread on your bike build......you did a magic job on that mate......wanna sell it...

[MX?]

G'day there Jack. Nothing happening yet, still trying to get on top of the house restoration.  not to mention the nice new 15m x 8m garage........that I can't even move in at present.
I'm running a bog standard motor (Only has a pipe) at the moment, but have a bloody good time on it all the same. Hoping the small upgrade will supply a few more! Hope your going to post up the rebuild pics? I'll get onto mine sometime this year (not much left though now ) soon as I tidy up the shed. XLint have some good (if pricey) gear.

[jack82]

The shitbox arrives home......




Should have waited till I got a manual but could'nt help myself......





Now for some questions........I'm putting a 270 or 305 kit in it.....the stock carb is farrked.....What's a good replacement??.....was thinking a VM Mikuni but not sure what size??.....30/32ish ??

Also does anyone know where I can get NOS or good secondhand parts in Oz??

ANY info,tips or tricks related to the XL's would me much appreciated.

[LWC82PE]

Have you been to the Oldrice website? lots of XL hop up articles there.

[fatboyracing]

If you are going for a bigger bore then I would go for say a xl350 carb or simular the VM Mikuni32/34mm would work fine also,in the pictures the old girl looks very original good restorer good luck

cheers
Fatboy

[MX?]

Looks similar to mine when it arrived......hope it costs you less than mine. 
http://www.tiaromotorcyclewreckers.com/Nos%20Honda.htm did have NOS Bassani pipes at one stage for a couple of hungy, also picked up a 305 kit for around US$90 delivered on Epay a while ago.

[Tim754]

Tips from one that has been there and enjoyed doing that to XL 250/350s . !!!!!Find an electronic ignition system!!!!!!! All the engine work in the world fails as the stock points / magneto system cannot handle the job, even a stock XL 350 side port in fresh condition is a fun competition machine but ohh the ignition will start to  break down, pop ,bang and fart dying as you near the end of a moto  leaving you pissed off with these fine four strokes. Change the boiled oil after every second heat..... Having bushes or bearings fitted to the camshaft not just the soft alloy they sit/shit in is another tried and proven reliability mod.  Cheers Tim754. 
    Did I mention to change the oil after every second moto ? After every race if it is a warm day.

[cyclegod]

!!!!!Find an electronic ignition system!!!!!!! All the engine work in the world fails as the stock points / magneto system cannot handle the job, even a stock XL 350 side port in fresh condition is a fun competition machine but ohh the ignition will start to  break down, pop ,bang and fart dying as you near the end of a moto  leaving you pissed off with these fine four strokes.

Any suggestions or real world practcal help and/or links to finding an electronic ignition that fits and works would be gratefully received.

[sudman]

I have a XL350 that I race in vmx in kiwi land & they are a lot of fun, 36mm carb on the 305 motor is the best option 32mm on all but stock 250 works as well, CDI is a good option which I am currently fitting, but if you fit Honda points not after market & run them at 12thou they work fine as I did all of last season in that trim with no problem, but when you put the compression up you will need a bigger spark, they also love bigger pipes, I run 1 5/8 header & free flowing muffler put that with a bigger carb & the stock engine will give you about 20% more power every where.

Happy thumping

[Tim754]

Cyclegod  I had a couple of NOS Martek electronic set ups,that I found in an old wreckers. Both sets never missed a beat even on the 420 at 13 to1 unfortunately both were destroyed in a shed fire. Lozza may be able to set you on a good path. Cheers Tim754
Wish I still had them as they are the same set up as used on SL125