Don't want these Ads? Why not sign up as a Trials Central Supporter.

pmk

Birkett SY250R mods question

22 posts in this topic

I have an '09 ex Birkett team bike. I concur with the mods previously mentioned, I would add, to my knowledge, the cranks were trued and welded to stop flywheel scissoring (not that it was a problem on yams anyway?) , mine has an Ohlins shock,(not sure that was a birkett mod) I know some owners who have strengthened the top shock mounting point as the bolt hole can elongate with time/wear.  HTH.

Share this post


Link to post
Share on other sites

Don't want these Ads? Why not sign up as a Trials Central Supporter.

5 hours ago, the yukon sizzler said:

I have an '09 ex Birkett team bike. I concur with the mods previously mentioned, I would add, to my knowledge, the cranks were trued and welded to stop flywheel scissoring (not that it was a problem on yams anyway?) , mine has an Ohlins shock,(not sure that was a birkett mod) I know some owners who have strengthened the top shock mounting point as the bolt hole can elongate with time/wear.  HTH.

Thank you for the reply.

Is there any chance you might have photos or can better explain the mods done?

Most seem pretty straight forward, the frame tab to allow easier subframe removal is most intriguing.

The repositioning of the thermostat seems obvious, but a photo would be a benefit.

Still no reply from Birketts.  I should message them again.

Edited by pmk

Share this post


Link to post
Share on other sites

Bought the 2005 SY250R.  Does not appear to have been ridden in competition and otherwise is in very good condition.

Sent a second message to Birketts via their website page.  Asked if they have stock on spares and if they had the mods posted somewhere on their website or archives.  Hope to hear back from them.

Plan to give the machine a good look over and replace all fluids and grease the steering and swingarm pivots.  Also, since the mid exhaust tends to get punctured by the engine case, I will ensure that is addressed.

Should be fun entry level and learning machine to compliment the 73 MAR.

This trials riding is addictive, even when learning and being kind of a hack about it.

Share this post


Link to post
Share on other sites

SY tuning wasn’t all about making them more wick, lots of people swapped the flywheels from older bikes and Tyz’s (3.1kg) to give better grip, the Tyz had steel reeds and stoppers, the stoppers where used to smooth the power at the top end, there was a little porting done too. 

I had one of those water pump houses, while they sound a good idea the I was always worried if it took a hit the case would get trashed.  

Share this post


Link to post
Share on other sites
5 hours ago, godzilla said:

SY tuning wasn’t all about making them more wick, lots of people swapped the flywheels from older bikes and Tyz’s (3.1kg) to give better grip, the Tyz had steel reeds and stoppers, the stoppers where used to smooth the power at the top end, there was a little porting done too. 

I had one of those water pump houses, while they sound a good idea the I was always worried if it took a hit the case would get trashed.  

Interesting about the reeds and water pump housing.

On my SY250, reeds in it now are fibreglass with no true stoppers.

The water pump housing is stock, but I did get the 2005 Scorpa options catalog with the bike.  They show a slightly different housing where the fwd hose spigot extends more towards the radiator.

Share this post


Link to post
Share on other sites

A0_E773_E3-7252-41_D2-_B091-5_CFE7_EBD05

The covers where pretty rare, mine was the only one I ever saw, I gave it to a mate who’s a bit of a collector, they where cast and the hose angled, the hose needed to be shortened a bit, I’ll see if I have a pic later. 

Edited by godzilla
1 person likes this

Share this post


Link to post
Share on other sites

I emailed Birketts about a current Scorpa question though their website and never got a reply.  You might need to phone them.  Mike at the Tryals Shop had some trick SY250's, might want to talk to him about that too.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now