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Technical Motorbike Help

VFR - Shims inspection.

VFR - Shims inspection. - Forums [Biker Match] VFR - Shims inspection. - Forums [Biker Match]
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VFR - Shims inspection.

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1999 - VFR800 not VTEC - is a shims inspection something I should have done ? is there anything I should be looking for to make me think I have a shims issue ?

I have a service every year plus anything else that needs doing.

Advice ?????????/

   Update Reply
VFR800AJ @ 20/04/2016 18:53  

this might help

   Update Reply
bluesbiker @ 20/04/2016 21:13  

Does it sound rattley. If there set spot on it has quiet an effect on the running but tbh vfr's are built like tanks and can go very long distances before any wear requires valve adjustment.

My last vfr's went nearly 90,000 miles before it needs adjustment.

Using good quality super unleaded fuel will aid the prevention of valve seat wear which is the main cause of valve sinkage.

   Update Reply
Deleted Member @ 22/05/2016 21:48  

Although the valve clearance hardly ever needs adjustment with engines that have buckets and shims. Measuring the clearance to see if the valves are in the specified range is always a good idea :-) particularly on older bikes
This may help if you haven't done it before.

i hope it's of use :-)

   Update Reply
MrBen @ 23/05/2016 09:06  

don't assume that because there isn't any top-end ("tappet") engine noise that everything is ok.
on bucket and shim type valve set ups the shims don't wear,

what happens is the valve seats wear from the constant hammering action of the valve head hitting the seat, causing valve recession (the valve moves up into the cyl head) which closes up the gap between the bucket and shim and camshaft. so the valves become quieter as they wear not noisier as most people assume.

if the valve clearances are not adjusted what will eventually happen is the valve will receed far enough into the cyl head that there will be no clearance and the valve will be held off the valve seat. this will cause a loss of engine efficiency but more importantly with regards to the exhaust valves they can "burn out" because they use the contact with the valve seats to dissipate the heat they absorb from combustion.

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mikedabike @ 23/05/2016 17:51  

Thats why i always advise using a decent super unleaded fuel as it helps wuth the wear on the valve seats.

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Deleted Member @ 23/05/2016 19:40  

Mikedabike is absolutely correct, the clearances close up on shim systems rather than opening. Everything sounds fine until you get a load of ruined valves and seats.
Get them checked. If I remember right it's a bit of an arse pain on the VFR motors, but the alternative is really expensive.

   Update Reply
Deleted Member @ 24/05/2016 15:39  

it's not too bad to check the clearances, but a PITA to adjust them. But there again, double-jointed fingers come with the territory for VFR owners

   Update Reply
Wills @ 24/05/2016 21:39  

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