Yamaha TRX850 Enthusiasts Forum

Well I have finally had enough of the oil consumption - bloody ridiculous! and have purchased new rings, valve stem seals, new cam chain, seals and gaskets.

However while I am at it I was thinking of Kent Cams and a porting job - any ideas on where I can lay my hands on a set of Kent Cams - a dealer in the West Midlands would be good. Does TTS do them as they don't seem to deal direct

Thanks in advance

The Kent Cams are a regrind - you send the cam shafts to them direct & they re-profile. They can also supply new camshafts but they are proper expensive as they are made to order

As above ^^^

BUT ..... I wouldn't bother unless you are also gasflowing / porting / skimming head etc as the benefit will be minimal.

And if you do all of the above, you may as well 'invest' in a big bore kit

(this is assuming you already have FCRs and a proper exhaust - if not that's where you shoudl spend your money )

Yes got FCRs and big bore 2-1-2 exhaust, would like a steer on who can port the head, as have a spare head that I can send off for minimum down time

TTS did a good job on my ol' 900 and it had reground Kent cams too - 27,000 miles on the rebuild when I sold it on - no problems and minimal valve clearance change and no wear

Question for a those with Kent cams, as they regrind, they probably chage the base diameter. Is there any problem wth shims to get your vlave clearances? and what is the beggest shim size you can get?

Good question - dunno - clearances within limits throughout the time I had the bike

The base circle diameter is reduced by a fraction under 0.5mm.

Thicker shims to restore the valve clearances are widely available, an online search will turn up various sources. There are two common valve shim diameters, these are 7.48 and 9.48mm. Can't recall which size fits our engines ( old age creeping up )

None of the above is a much of an issue if you intend to use reground performance cams . Really no more difficult than shimming up a std engine.

Mark.

Don't think of it as a regrind, it's actually a re-profile to the lobes themselves which in turn offers different lift & duration. It will not change anything when shimming.

P.S. your spelling is getting worse Simon - go & stand in the corner!

Just wrapped cams up to post to Mr Kent + got all engine gaskets. Hopefully will post head for porting Saturday! Feeling excited! Will just need good dyno guy to set it up - Chris do you have any sway with Craig of Dyno tech or any other ideas?

Who's doing the porting ?

Got a couple of numbers, but will welcome reccomendations

SDN wrote:Just wrapped cams up to post to Mr Kent + got all engine gaskets. Hopefully will post head for porting Saturday! Feeling excited! Will just need good dyno guy to set it up - Chris do you have any sway with Craig of Dyno tech or any other ideas?

I see him most weekends so i'll ask the question for you - most of his work is car builds nowadays (V8 conversions,etc) but if it is just dyno set up you need i'm sure i'll be able to sort summat mate.

Have you gone for the YAM9 profile from Kent?

Yam9 yes that's the one. Hopefully should get all the bits back in a couple of weeks time

Wrapped head up last night and will be posting off this morning to TTS for porting and a head skim, will book a day off to rebuild. What I could really do with, is a set of cam followers (buckets) so I could dry run shim the head up. I don't suppose anyone has a set languishing in their garage? I could even send them the ones from the current head when I'm done. Chris any luck on Craig from Dyno tech on some dyno / set up time?