Shop says new piston rings required. Am I being conned?

[His Dudeness]

Taking the head off and replacing valve seals is doable at home.  You need a suitable torque wrench and a valve spring compressor.  Read the manual a few times so you know the procedure and how to time the engine. If you go slow and careful you should be able to do it. The hardest part would probably be getting the exhaust off without shearing studs.

[HarryHornby]

This is WAY above my skill level! Trust me!  :\

[dangerdre]

People mentioning washed out worn bores and valve seals...has the OP said the bike is smoking?

[Dinger1962]

Hi went through the same thing with my fzs600 --even had the carbs cleaned at shop no change--havin been through the electrics etc still convinced it was fuel i borrowed my mates carbs off his bike and was up and running on all four in no time --bought a set off fleabay happy days good luck-

[Gnasher]

Just spoke to the shop and they said they had done a crankcase pressure test which resulted in oil being pushed up into cylinder 3 which would be causing intermittent miss fire and it definitely needs new piston rings. Cost likely to be 6 hrs labour at £60 per hour. £150 for new gaskets and £150 for Piston Rings. Plus £108 already spent. £768 +vat.

Oh yes they're conning you, what utter bollocks.  :rolleyes


When you do a crankcase pressure test, all you can do without stripping the engine first is tell that compression is being lost to the crankcase, because the compression rings/bores are worn or stuck.  Lack of compression on it's own doesn't give you misfires just lack of performance, leaking valves will give you a misfire, but on a bike with only 40k it's very unlikely if that is the true mileage.  I've worked on these bikes since they were introduced and in all that time I've seen only a handful that have suffered lost compression and required major rebuild work and these were badly abused 60k plus bikes your is 40K.  Let's assume for a minute they're right just changing the rings wont solve the issue, if the rings are buggered so will be the bores and most likely the pistons.


Your readings of 15 & 12 are within spec, I'm pretty certain your misfire has nothing to do with your engine.  The carbs are your issue, mostly they just need cleaning out of the pilot circuit, which is easy but as with everything it's easy when you know how!


Mate change your dealer now. 
 

[/size][size=78%]      [/size]