nasty leak in gasket where engine splits

8)
Hi
after a recent unsucessfull overhaul of my vf 500 which i loved so
much[before the overhaul] I have a leak where i was trying to split
the engine I was trying to break the seal and as it happens i failed
but of course it was"nt quite that straight forward,i seemed to do a
little too much probing with hammer and screwdriver and i have a leak.
I must point out i also had another leak in the clutchrod seal which
was both nasty and annoying which is fine now, so they really do come
in pairs. Any advice now from the experts, what will plug this leak?
Is silicone an option?It says it stands up to 100 degrees celcius but
is that sufficent
thanks
ulick

 

No.

The only real solution is to strip the engine, alloy weld the damage to
the cases, machine down, reassemble.

You *might* get lucky with chemical metal, but to get this to bond well
you really need to strip the engine as well so wtf.

 

The right way to separate the cases is to gently hit one case half with
a large rubber mallet while holding the other half with your other
hand.

( Horizontally split cases are only held together by rubber cement and
a bit of friction at various dowel pins once you've removed all the
bolts.)

You could try an oil-resistant silicone, like the blue RTV that's used
for gasket making. But I would recommend thoroughly de-greasing the
area that leaks with brake cleaner and then forcing some two-part epoxy
into the gap with your finger.

Use something similar to JB Weld or whatever you can get in the UK
that's like that. You've probably seen it around. One tube has white
goop in it, the other tube has dark grey or black goop and you mix
equal parts together and it comes out dark grey. It cures in about 8
hours and will stay on the part for years and years if you've degreased
the surface properly. Epoxy will resist gasoline and oil once it's
cured. If you have a heat lamp to point at the engine cases while the
epoxy is curing, use it.

Surface cleaning and preparation of the surfaces by roughening them
with sandpaper is critical to getting the epoxy to stick.

 

HI
thanks a mill Krust and the old man for some usefull tips,yes you are
right ,its the bloody oil and paint that makes it a bit tricky to get
a result and also the proximity of the leak to the rubber surface
right behind the front sprocket.Taking the engine apart again is not
an option,one of us would not come up breathing.It was actually a mate
of mine who was a little bit liberal with the hammer and screwdriver
although I must admit I am a bit partial to wielding the old hammer
from time to time.Howsever the clock cant go back so we’ll have to
sort something along the lines of what you say
rgs
ulick

 

Thanks Older
Your advice is of course technically correct to restrip the engine but
its simply not an option.I am not worried though I am not now totally
dependant on the vf for commuting around the city, I recently aquired
a 650 bros 1990 immaculate bike a better bike in most ways but would
you believe the vf 500 with the v 4 engine is a smoother bike changing
through the gears especially the high gears,its very noticeable the
vfs much smoother riding on low reves in 5th or6th.
rgs
ulick