Damaged piston (VFR400)

[fastdruid]

Originally Posted by Spanner Man

NC30's have pretty tough engines. However, as the valve shimming procedure is pretty fiddly most garages don't bother doing it. So it is possible to burn a valve.

+1 it is a PITA to do[1] and normally when checked they are fine...

It does make quite difference to starting and running though to have them spot on.

Also balancing the carbs makes a difference and again is a royal pita to do.

Druid

[1] Although doesn't need cams out like the SV as its shim over bucket.

I didn't think about the compression test.
That would be why there is no compression if it's not turning over :S

I really don't think I should let them keep my bike.

They want to charge me £50 to tell me i need a new piston..

[yorkie_chris]

Dave I think they're pulling your p*sser.

Originally Posted by ThEGr33k

Turn it off of the crank? I have no idea how you do a compression test though to be fair

You screw the tester into a plug-hole, hold the throttle wide open and crank it.

Dave, get your bike back off them, they sound a bit un-clever TBH. Can you get your bike to spannerman? I know he has a fair bit of experiance with those little V4's.

good luck, i hope the engine is ok and its something simpler, keep us updated

Apparently the engine is turning over. :s

Originally Posted by EssexDave

Apparently the engine is turning over. :s

Really? From reading the thread, I thought it was you that was being turned over.

Dan

[yorkie_chris]

So they charged the battery and ran a compression test. Ask for what the values were on all pots. And if they had the throttle open when they ran test

Battery directly to the starter, if it has starting issues.

Need to do it twice if low with and without oil in the bore, as above throttle must be fully open.

How hard is it to rebuild an engine given unlimited time and funds?

Originally Posted by yorkie_chris

So they charged the battery and ran a compression test. Ask for what the values were on all pots. And if they had the throttle open when they ran test

good call, you wouldnt expect there to be no compression on any of the 4 cylinders, unless you had just the most aweful luck in the world