R1-Z: the joys of endoscopy

[biggz]

And it was all going so well, OK reasonably well.

Top end rebuild about 1400km ago, so a bit loosened up and running well enough, at least to the point where the road tells me to back off before the bike stops pulling.

A bit of a warning in that the coolant level in the header mysteriously rose, but then it rises when it gets hot anyway. Time to have a look in the bores - rats, coolant drip in the R/H cylinder.

My question: the head went on with a gasket, Loctite 3020 and copper washers under all the C/H nuts. Thinking being to equalise, as far as possible, their torque resistance. Is there any reason why that was a bad move?

At least the weather is rubbish, so I'm not missing any riding. Any comments appreciated.

Laurie

[oldiggy]

Was the head skimmed flat at top end overhaul ?or did you rub head on a flat surface with some grinding paste to make sure flat ? Scratched head on head bolts ? Torque wrench ok ? Have you re torqued head bolts again after heat cycles.

[biggz]

Was the head skimmed flat at top end overhaul ?or did you rub head on a flat surface with some grinding paste to make sure flat ? Scratched head on head bolts ? Torque wrench ok ? Have you re torqued head bolts again after heat cycles.

Oldiggy: in order - yes, also yes but used ultra fine wet and dry, not that I recall, recalibrated recently, yes.

I'll put the torque wrench on the case, and if anything moves very much (it shouldn't, surely, this far in), I may give it a run again. If nothing does, head will come off. Also I might give Permatex Copper Spray-a-Gasket a go as a belt and braces policy.

Laurie

[oldiggy]

I see BDK engineering are advertising I thought they had packed up, you could always go down that route and have a skim and O ring mod. When head is off put a flat edge over top of barrels.Rest head on barrels without gasket and shine a torch across to see any light leakage. Maybe when refitting head slacken off barrel base nuts slightly torque head down then retighten barrel nuts.

[biggz]

I see BDK engineering are advertising I thought they had packed up, you could always go down that route and have a skim and O ring mod. When head is off put a flat edge over top of barrels.Rest head on barrels without gasket and shine a torch across to see any light leakage. Maybe when refitting head slacken off barrel base nuts slightly torque head down then retighten barrel nuts.

Just ran the torque wrench over the nuts, and unfortunately no easy solution there.

I'll possibly go to O rings if the next gasket fails - as longer term fix it seems to make a lot of sense. The straight edge looked OK when I checked before I put this one on, but I didn't think of the head on minus gasket (perhaps with nuts finger tight?) and look for light. Base nuts? yeah, but blimey this is complicated. I do wish that Yamaha had built it with separate heads, but then two thermostats and so on. While they were at it, they might also have split the PVs and used a four cable servo... Where have I seen that before?

Thanks for the suggestions, Laurie

[tzar250]

Frustrating for you...

May I ask if the head gasket was OEM Yamaha or a pattern part.

I have used OEM or Athena head gaskets with no problems but have had similar issues to yours on the couple of occasions that I have used more generic pattern gasket sets. 

There was also one time when there was still a trace of the black paint from the old gasket left behind on the top of the cylinder which caused coolant to seep out.

[biggz]

May I ask if the head gasket was OEM Yamaha or a pattern part.

OEM. I used anti-seize when fitting the studs - perhaps a bit sneaked out, though I cleaned with white spirit and then meths IIRC.

I'll get there in the end... L

[oldiggy]

When my barrels were off I put the head on the barrels with no gasket and checked with my thinnest feeler gauge to see if it could enter anywhere, it was just entering slightly in one spot so when I sent my barrels off to Pjme for a rebore I got them to skim the base of barrels and top of the barrels so I know everything is flat to each other. I made my own one piece base gasket to make up the lost clearance. Be aware some head gaskets are different thicknesses so measure with micrometer as will have a bearing on your squish clearance. I was going to send my head to BDK for O ring but they were permanently closed so rubbed mine down on a flat piece of glass ( old microwave oven glass door).

[biggz]

When my barrels were off I put the head on the barrels with no gasket and checked with my thinnest feeler gauge to see if it could enter anywhere, it was just entering slightly in one spot so when I sent my barrels off to Pjme for a rebore I got them to skim the base of barrels and top of the barrels so I know everything is flat to each other. I made my own one piece base gasket to make up the lost clearance. Be aware some head gaskets are different thicknesses so measure with micrometer as will have a bearing on your squish clearance. I was going to send my head to BDK for O ring but they were permanently closed so rubbed mine down on a flat piece of glass ( old microwave oven glass door).

Thanks for your reply, and now more occurs to me:

i) My barrels were bored +1.00mm by PJME and the head was opened out to match at the same time. They also worked an OEM head gasket to suit. Can anyone suggest how I can do the same when I buy a new gasket from Fowlers? (All I can think of is a flapwheel on a slow drill with the gasket gently supported in stiff card or similar.)

ii) 2MA manual states that torque settings are for "clean, dry threads", 3XC manual at the same point makes no comment - though I haven't scanned and had translated the whole thing, Norbar recommends clean, lightly oiled threads or words to that effect. I went recut, cleaned, degreased/de-oiled and dry when I assembled - what does everyone else do?

Thanks all

Laurie