Ah yes I have decided to conquer the valve train noise on the inlet side of the valvetrain. Got a dealer to fax me all the relevant pages from the factory manual, my local dealer doesn't even have the manual, a bike shop in Brisbane helped me out.
Anyhow the valve clearance measurement from top of valve to sub rocker arm and it should be .10 - .20mm. If not then each valve clearance needs to be adjusted using tappet shims, these cost about $8 each and you could easily need 8 of them if you are outside of the desired clearance range. Ususally even the noisest 250VVT will be ok on this measurement.
Next thing you measure the sub rocker arm play, it needs to be .10 - .25mm clearance with cams properly positioned (one lobe at 12oclock and the other at about 9 oclock facing rear of bike). This clearance needs to be check in the lo side operating position and then again in the high side operating position.
Both clearances need to be the same, the lo side clearance is best adjusted by replacing the sub rocker arm shims with correct height to get clearance correct. Once this is pretty right then shift sub rocker pivot arm to Hi side operating position and adjust the conventional tappet screws until the .10 - .25mm is achieved. The sub rocker arm shaft needs to be rotated 140 degrees in direction of normal cam rotation to set it to lo side operation and the reverse to set it to high side operation. This can be done after you remove the little cover at each end of the 2 shafts.
All in all there is said to be 24 (according to manual) measurements in total just for the inlet cam. It seems daunting, its not unless the cam has to come out to fit new tappet shims, but like I mentioned this is unlikely.
When I measured my subrocker arm clearance in the low setting I got a measurement of 1.00mm
, this is why the VVT's get noisey, it was ok on the high side since I could adjust the tappet screws to bring it within specification. So I need some serious shims
NOW the important part is that Suzuki Aus carry no spares of any kind much in stock for the GSF250V, everything is back order and often can take 4 weeks easy.
The sub rocker arm shims to correct the lo side clearances are $11.00 each and often a full set of a certain size is needed, $88.00 for 8. NOT CHEAP.
I love this engine so much its not funny, the way it can pull from even 160km/h for a 250 is just simply unbelievable. Such a tiny motor but so much power. I get 180 km/h tapped out and it does it quite quickly. But the down sides are the complete lack of parts for immediate repair and the incredible cost of the parts aren't very funny. I think a VTR250 Honda would be a better bet, just 2 cyls and no fancy valve mechanisms, would probably be shim type. I bet the adjustments for them aren't needed very often either. The honda wouldn't hold a candle to the GSF250V in performance but maybe the exhaust note from a nice staintune would nearly make up for it.
So if you know anywhere I can get some shims without waiting forever (Suz Aus have none) then I would be most interested to know. I do recall a company that makes shims that advertises in some car and bike mags but can't find them at the moment.
Topic: GSF250V sub rocker arm shims (Read 2978 times)