Yamaha TRX850 Enthusiasts Forum

I have never had to remove a plug from this bike before as the service dudes usually do it. BUT, my plug seems to be dead and so to my question. How the hell do you get at them without dismantling half of the bike? Is there a trick? Can the radiator be flexed forward without disconnecting the hoses? And lastly, what idiot designed this engine? LOL...I guess it's the 5 valve config. that doesn't allow the plugs to come in from the side like a lot of other twins but man, what a pain.

Kobo

Can the radiator be flexed forward without disconnecting the hoses?

Yes.
I put Iridium plugs in mine so that I didn't have to worry about changing* them too often.

*read checking, I also can't be bothered pulling the bike half to bits.

I undo the radiator mounting bolts, then you can move the radiator forward and a bit more out of the way.
Grab your spark plug tool and commence removing both the plugs and skin from your hands.

Don't forget to blow out those plug wells before removing the plugs.

Thank you kindly Lads. I will get right on it and though exxy I like iridium plugs....

Kobo

Kobo1 wrote:And lastly, what idiot designed this engine? LOL...I guess it's the 5 valve config. that doesn't allow the plugs to come in from the side like a lot of other twins but man, what a pain.

Kobo

The idiot who designed a 5 valve dry sump engine with a 270degree crank, probably didn't account for the idiot who couldn't remove a spark plug

What an idiot!

Con Rod wrote:

Kobo1 wrote:And lastly, what idiot designed this engine? LOL...I guess it's the 5 valve config. that doesn't allow the plugs to come in from the side like a lot of other twins but man, what a pain.

Kobo

The idiot who designed a 5 valve dry sump engine with a 270degree crank, probably didn't account for the idiot who couldn't remove a spark plug

What an idiot!

Con Rod wrote:

Kobo1 wrote:And lastly, what idiot designed this engine? LOL...I guess it's the 5 valve config. that doesn't allow the plugs to come in from the side like a lot of other twins but man, what a pain.

Kobo

The idiot who designed a 5 valve dry sump engine with a 270degree crank, probably didn't account for the idiot who couldn't remove a spark plug

What an idiot!

What's with all the aggression Con Rod? Did I kill your dog in another life? Did you not notice the LOL after the question? It's there to point up the sacasm a bit more for the thickies who don't get i....OH Wait....
Get a grip....I love these bikes....

Kobo

Even if you dismantle half the bike you'll still find the idiot that designed it welded a frame tube right above the spark plugs as a final "f*ck you, sucker!"
Yes, you can loosen the rad bolts to swing it forward without disconnecting the hoses to give you another 2mm of space, but you still need the delicate hands of a gynaecologist to get in.
But hey, it's just another 'character trait' of the TRX

Also...once you get the left plug changed leave the lead off or you'll never be able to reach the right hand plug...you have to reach across the top of the left one to reach the right. Only takes about 90 mins to change 2 plugs

I've shortened a spare yamahe plug socket and welded an old socket on top
Just remove the radiator...save damaging and it wouldn't hurt to renew the coolant anyway.
Haven't done the job a while now....iridiums.

Whilst doing the job, one recalls boxer twins previously owned

if you think that's bad you should do the shims on a Harris Magnum 1 Z1000, you have to drop the engine to do them

Geez you guys can whinge. The Trixxie is a piece of p#$s to work on compared to some bikes. Try removing the plugs from a ZX14R after at least 40 minutes to remove the necessary bodywork and lift the tank sufficiently you might be able to see the bastards. Try a '95 CBR600F3, again remove the tank, airbox, all the front bodywork, drop the radiator, remove the air intake ducts and then you can get the mongrels. Just 2 from a lifetime of working on bikes. Don't get me started on some cars or other machinery!

Dav if you've owned boxer twins before then you know they have their own problems.

For those of you who want to service your own TRX's, remove the rider's seat, disconnect your fuel hose to the pump, disconnect the vacuum lines, remove the 2 x 6mm cap screws at the front of the tank, tilt the tank back and support, then remove the airbox ( 2 x hose clamps and 2 x bolts from memory) and there are your spark plugs and valve cover. Easy as. The hardest part is doing valve clearances if you don't have the necessary replacement shims, but these can be obtained through SERCO in Brisbane. The total time to get the tank lifted and airbox off should be no more than 20 minutes if you've never done it before.

Loosen rad, tilt forward, 15 minutes job done, large hands, no problem

Loosen rad, tilt forward, 15 minutes job done, large hands, no problem