Yamaha TRX850 Enthusiasts Forum

I posted a query a few days ago ref my leaking oil tank, I now have a few pics of the groove in question. I have since found out that my bike has a TDM 3VD motor fitted, not sure if it has the TRX crank etc but more on that later.
The oil tank is marked 4NX, and the groove pictured doesn't correspond to anything on the crankcase. This groove seems like an obvious weak spot that would fill up with pressurised oil and eventually breach the thin section of gasket surrounding it. Can anyone shed any light on what this groove is for on a complete 4nx engine? I think i'm going to fill this groove with liquid metal to hopefully seal it off. Any input greatly appreciated!

Sorry people, my computer is being a complete S%*T and won't let me attach images! Will keep trying!

Even without seeing pics I know the 3VD has a steel oil tank and would be surprised if it would be a direct match for the alloy TRX tank. Tonydevil should know more

Really need to see pics on this one...

You'll probably need to resize them or upload them to a flickr acocunt...

So, the pics show the bottom face of the lower half of the oil tank and the groove that doesn't relate to anything on the 3VD engine.
Any thoughts on this before the liquid metal comes out to smooth it over?

Yea weird, open loop!
Fill it, it`s some sort of tooling stop/start point I reckon, really cannot see why it`s there in all honesty.

Thanks Mincehead, just the re-assurance I need. I hold you fully responsible for any future catastrophes!!

Yep, will be filled and smoothed tomorrow.

What do you mean by tolling?

My spelling! should have read TOOLING.(which in fact it now does)

I see, thought it might have been an engineering term! I wonder if it would relate to anything on a 4xv engine?

Thanks for your input. Hopefully filling this groove and new gaskets should seal her up once and for all?......

Well it should do, the hole in the casting goes nowhere and on the mating face you have is totally redundant.
I simply can`t remember what or if it does anything on the TRX oil tank/casing either.(I`m not near my bike).

Maybe there was a problem with oil mist/leaking at that point and they machined a groove to squirt some extra silicunt into the groove????

Mmmmmm,

A good point well presented, hadn't thought of that.
I hope you're not right as i've liquid metal'd it over already! Got the new gaskets so should be getting her back together in the next few days. Will let you all know the verdict.