Yamaha TRX850 Enthusiasts Forum

Help! I want to check valve clearances so have attempted to take off the rocker cover ( engine still in frame) however the metal tube that sits inside the rocker wont budge, it looks slightly rusty down near the bottom of it but nothing too bad... is this one of those steel to alloy self welders
whats the deal with these? is it an engine out job to get it free?, Ive tried penatrating oil, and a light knock with a hammer and lump of wood and also some a stilson wrench to try to give it a bit of a twist... all ive managed to do is score the surface of it and squash it a bit....

Have you removed the securing bolt ? Mine wouldn't budge so I soaked it with wd40 overnight gave it a few taps with a rubber mallet then it came out quite easily.

yep removed the small bolt, I will try more pen oil /gt85 /wd40
any other hints and tips welcomed!

Sadly Cal you may have to get right tough with it to get it out, I had to mine.
I actually ended up using a 1/2" socket extension and kept rocking it to and fro while giving it the occasional whack with a hammer to break the (you got it right), steel to alloy electrolytic / galvanic corrosion!
It`s a lovely little road salt trap down in there, the secret ingredient that starts the whole problem off.
My coolant stub was quite badly corroded and it was fooked completely by the time I got it out, luckily I found one in a breakers yard in good condition for little money (Yamaha wanted something like 26 quid from memory) and it had several coats of Smoothrite applied to it and oven baked to `hard as nails` before I installed it with a new O-ring and a liberal coating of water pump grease.
I used a new stainless cap screw to hold it in place, again the thread coated liberally in water pump grease, I don`t expect any further problems with it now.

bollocks
Think i might need to find another one too, just hope the bit thats in the head comes out without too much bother even if the rest of the pipe is fecked...that could be a right nightmare it the stub breaks off and leaves the part in the head still in the head....balls balls balls.

The bottom of the stub has around 3 to 5 mm proud that fits a recess in the top of the head Cal, it`ll come out but it`ll not likely give up easy and I`m betting you`ll knacker it getting it out if it`s a tight as mine was.
The electrolytic corrosion was so bad on mine it had actually eroded the head slightly where it fits but it still sealed ok with a new O-ring and a thin wipe of clear silicon as the belt and braces approach.

Slowly slowly catchy monkey!
been spraying with wd and letting it soak in for a few days, gave it a tap with a mallet and a bit of wood this morning and it has started to move, its came fairly loose now, enough to move by hand, (move by cut and bleeding hand after removing shards of metal, left from the stilson wrench scoring it ) still wont come out though, more wd please!

Maybe put a piece of doweling or a bolt into it so you can get some grips round the tube without knackering it ?

you have the right theory, Cal, Yamaha expects all the people who work on their bikes to use blood as a lubricant.

Gotcha!
A bit more wd 40 mixed with a few drops of the red stuff and out it came, it put up a fair fight but will live to see another day.
Now onto the valve clearances.....

Well done Cal. Was the sealing surface on the head eaten away at all by the electrolysis?

ahh the joys of running a trx only in the summer... did take mine out though last year.. for a thorough inspection and clean... and it just popped out...

oops sorry...

Only had time to have a very quick look at it, Mince, but there is some marks and evidence on some electrolisisisis around there, nothing too bad though, a bit of wet and dry should clean it up, had a very quick shoofty at the valve clearances too only able to get 0.08 in the inlet (I didnt do them all it was a very quick look!)
I will spend a good bit of time checking and recording the gaps maybe tomorrow or Sunday but I think It will need shim adjustment

Handsome Jack, fuk you and the fuk'n pristene white horse you rode in on.......










Its all in good humour dont take it the wrong way

ahhhh you so kind thanks....

grrrr Grrrrr