Yamaha TRX850 Enthusiasts Forum

Well I've had my tea leaves read but how good are you at reading your plugs These are mine and this is the first time since owning the bike that I've changed them. Now, knowing what a pain in the a55 it is i think this set will last at least another 10000000000000K's as I've changed them to a set of NGK Iridium's.

So what do you see in the future for my engine

Plugs as they came out of the bike (left to right)

Left plug looks pretty normal. The right plug shows oil residues and carbon build up. So...............
Suspect valve stem seals, maybe bores a tad glazed, but I`ve definately seen a lot worse!
YES, they`ve certainly been in situ a while looking at the oxisidisation on the zinc / cadmium plating of the steel plug body.
Does the bike puff a little bluish / white smoke on the overrun from the cylinder the right hand plug came out of. I`m guessing she does?
Mine does too from both cylinders but only if the motors been pushed on a bit, I see it most when she`s on the dyno, not too bad though, she`ll go on a tad longer, the motor is going to be out later in the year hopefully anyway.

Here you go:

http://www.exx.se/techinfo/sparkplugs_c ... plugs.html

Mincehead wrote:Left plug looks pretty normal. The right plug shows oil residues and carbon build up. So...............
Suspect valve stem seals, maybe bores a tad glazed, but I`ve definately seen a lot worse!
YES, they`ve certainly been in situ a while looking at the oxisidisation on the zinc / cadmium plating of the steel plug body.
Does the bike puff a little bluish / white smoke on the overrun from the cylinder the right hand plug came out of. I`m guessing she does?
Mine does too from both cylinders but only if the motors been pushed on a bit, I see it most when she`s on the dyno, not too bad though, she`ll go on a tad longer, the motor is going to be out later in the year hopefully anyway.

Here you go:

http://www.exx.se/techinfo/sparkplugs_c ... plugs.html

Yep that sounds about right, as for blowing smoke don't know and no one has made any comments. She does use some oil and has a noisy tappet. My interest lies in the amount of oil on the thread of the right plug, which has me wondering if it's valve stem seals. I would do a leak down test but that will require me removing most ot the bike to get to where i need to be. But as there is the noisy tappet i might just pull the front end of and just sort the issue once and for all, valve stem seals and maybe a hone and new rings

Rod

interesting search and links someone had done a only couple of weeks ago on prices on TDM 850 top end parts from the US .. have a search Rod it won't be too far back

Cobba
I think I'll do a complete compression, leak down test, adjust the valves, rebuild the carbs first before thinking about a rebuild of the top end

Hopefully see you Sunday, rain holding off......

Rod

Here you go guys, the thread Cobba was talking about :

http://trx850.motomaniac.net/forum/view ... ves#p63224

I intend to use the US site for parts, so much cheaper! I`m planning on building up my BRAND NEW cylinder head later in the year with ALL new components apart from reprofiled camshafts, if money and time are on my side.

cobbadiggabuddyblooo wrote:interesting search and links someone had done a only couple of weeks ago on prices on TDM 850 top end parts from the US .. have a search Rod it won't be too far back

Wonderfull just what i need to know and store away for a rainy day....

Rod