Advice Please ?

[harvey145]

Hello Scorpa people!

Just bought my first trials bike, having owned various air cooled trials bikes years ago - which were only used for playing on. New bike 05 SY250. Been regularly used for 3 years. I was wondering :

How often do you change the silencer - and other parts of the exhaust ?

Ditto - piston, main bearings, etc ?

Do you recommend a mod into the float bowl brass nut that creates an easy way of draining the flaot bowl ? - because my bike has one ? !

The engine is a tad noisy and reminds me of a TY250 that I once owned - I always reckon it sounded like main bearings - but that could just have been paranoia ! I was spectating at a trial on Sunday and it struck me how quiet a new Gas Gas was that I happened to find myself standing next to.

All advice really appreciated !

Harvey

[harvey145]

Hello Scorpa people!

Just bought my first trials bike, having owned various air cooled trials bikes years ago - which were only used for playing on. New bike 05 SY250. Been regularly used for 3 years. I was wondering :

How often do you change the silencer - and other parts of the exhaust ?

Ditto - piston, main bearings, etc ?

Do you recommend a mod into the float bowl brass nut that creates an easy way of draining the flaot bowl ? - because my bike has one ? !

The engine is a tad noisy and reminds me of a TY250 that I once owned - I always reckon it sounded like main bearings - but that could just have been paranoia ! I was spectating at a trial on Sunday and it struck me how quiet a new Gas Gas was that I happened to find myself standing next to.

All advice really appreciated !

Harvey

[pete]

Hello and welcome!

There are some bikes/makes that just rattle as standard. I've not heard a rattly GasGas so I guess they are usually sewing machine quiet. Shercos' on the other always rattle - its a peculiarity of the breed. I'm not sure about the 2stroke Scorpas' I think its still the Yamaha engine though? I've never noticed one rattling but I've never ridden one so can't really say!

I've never heard of silencers'/ exhausts' being changed as routine, only if they get damaged in any way. Sometimes a silencer might get clogged with burnt oil etc but most people seem to clean them out somehow! Silencers especially aren't cheap! As for engine bits, many people I know do a complete stripdown once a year, some maybe once every two years. Mostly pistons last longer than ownership of the bike! Since everything's in bits bearings/rings get replaced 'just in case'. I've always reckoned on checking everything external every 6 months and re-grease nuts and bolts/spindles etc. The more often you grease the swingarm spindles the better! Mostly its just general maintenance.

Having said all this I'm sure there will be someone who does things differently - there always is!

All the best!

Pete.

[greggjflower]

You mentioned that the engine is a tad noisy, Scorpas do whine, its due to straight cut primary drive gears - less power consuming but noisier that angel cut. They sound a bit like a vacume cleaner, My mates are always telling me to change the bag!

The Scorpa engine is pretty bulletproof but if someone hasnt serviced the air cleaner it could have a worn piston, check the inside of the airbox for grit, if its gritty - worry!

Do you have the float bowl mod? or are you seeking one? Its a pain to drain the carb so I usually do it by tipping the bike on its side.

[harvey145]

Thanks for that,

Yes the brass float bowl drain plug had a small 90 degree pipe fitted (araldite?) onto which a tube was fitted (app size of overflow tube). I replaced it with a new plug - just wondered how important it is to drain the bowl after use ? My CRF250 is very fussing about starting unless the bowl is drained and fresh petrol let in before use (only when it's been standing for a week or so of course).

I guess laying the bike over is a quick answer ! - or turning the fuel off and letting it run itself dry.

Thanks again guys.

[greggjflower]

if there is water in the float bowl then it wont help to turn off the fuel and run it dry. But should you find an engine that can run on water could you please let me be the first to know?

Edited November 23, 2007 by greggjflower

[nif40]

The whine noise you are hearing is normal, however if you are hearing the top end rattle (which is what I suspect you are hearing) you should dig a little deeper. I have several friends I ride with (all ride scorpa except for me) so I know what a scorpa should sound like. (1) of the (4) scorpa's started "rattling" (worst when cold) and this persisted thru our trials season. Upon further inspection, it was the piston/bore wear. I would pull the cylinder and visually look it over and get the bore measured. When you inspect the bore you will find that the bottom of the cylinder will have little to zero wear, but as you move up the cylinder toward the top is where you will find most of the cylinder wear. Go to your local trials shop and give them your bore measurements (if the bore is still in good shape) and they will give you the next recommended pistion size for your bike. This should fix the noise you are hearing. If the noise you are hearing is noticed upon every revolution and is more audible at idle than at speed I bet this is the problem.

FWIW: My buddy waited too long on his bike and had to replace the cylinder as the piston wore into the top of the cylinder. After the rebuild it sounds like a sewing machine, but waiting cost him $550.00.