Unscheduled winter project ?

Well the new front pads arrived this morning for the GFR so I took it
out to bed them in. Good ride to the Greasy Spoon. 100% better straight
away and bedding in nicely. As the definitely top spec. 2T oil works its
way through the system I start to give it the beans a bit. Very
satisfactory.

On the way home I really start to explore the rev range. This motor
seems to have significantly more go than the other one. Interesting
speeds attained without need to get tucked right down behind the screen.

Taking it right to the red line for the last few miles. Lovely.
Screw it up the final bit of NSL dual carriageway, passing a boy racer
in something or other who tries and fails to tag along as I pitch in to
the last sweeping left hander[1] at x mph. Snick in to 6th and hammer up
towards the last roundabout to give the pads a final bedding in. Going
really, really well. 11000,12000,13000... Lozzo may guess what is coming
next.

Rapid reduction of forward progress brought about not by the brake but
an instant cessation of engine activity. My reflexes can't be that bad
still because I whip the clutch in without thinking just like on the old
Rotax. Coast to a halt.

The temperature gauge is higher than I have ever seen on the other one,
but nowhere near the red. This is not totally unexpected as the lower
section of the radiator is masked off with foil to avert the dreaded GFR
cold seizure syndrome. The motor spins up on the starter but no sign of
life.

Recovery is effected not by Auntie Carole, but by courtesy of an omnibus
(I always carry a couple of quids in a back pocket) and trusty
Skoda/trailer. Probably in less time than it would have taken for a
recovery vehicle to reach me.

So prace bets now.

1) Just a cooked plug or ignition fault?
2) Holed piston?
3) Smeared ring lands and trapped or broken rings.

It spins over possibly ominously fast and my pessimistic nature is
fearing 2 or 3. Remember what I said to Champ about 100% spares kit?
This wasn't really what I had in mind.

Just off to get the plug out in the probably vain hope that it is just
that, but it looks as if SWMBO's CB250 refurbishment will have to wait a
while. I might Nige out the SOC pug to finance the new piston/cylinder
that may be required.
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

2).

JB

 

This goes so well with the old adage "They always goes better just
before they blows up, boy".

I'd go with two, then. Too.

Tough luck, old man. Stick to 4T in future - the choice of gentlemen.

 

2).

JB[/QUOTE]

Perhaps finding a Champion C55C 'Racing' plug in place is a clue. In
fact now I know who the original owner of the bike was, its impressive
performance comes as no surprise. Though it doesn't sport the special
Frigerio expansion chamber it did at one time. Problem being that both
the last two owners have almost certainly bimbled it too gently about in
an un-GFR-like way. I caned the other 40000 Kms example round several
sessions at Cadwell last week with no ill effect.

Plug is sparking strongly, so unless its sparking at totally the wrong
time for some reason it looks like 1) or 2).

The plug is very clean. Paging Lozzo or a two-stroke guru to look at
this rather blurry photo.
http://www.ps-fisher.demon.co.uk/pickchurs/gfr_plug.jpg

Wouldn't say it was obviously running lean, but I am no expert at
reading plugs. Pretty effective 'chop' whatever the cause.

Shining a torch down the plug hole doesn't show any obvious signs of
mice being at the piston. From my experience with the Rotax though the
damage may well be on the front, with a melted/seized land nipping the
top ring. Next step will be to drop off the belly pan, pop off the
expansion chamber and check for the dreaded aluminium metal sprayed
interior. Might then try and examine the piston crown, but I suspect the
electronic power valve might make this tricky or impossible.

In any case I will do a compression test. Assuming the likely result I
will pull the motor out and take it to John at Revs. Too
jewelled-watch-like for me to mess with (though I might risk lifting the
head to confirm the worst). As the GFR shares the same basic motor with
several of the Gilera 125s I am hoping Uncle Bob Wright can provide
whatever parts it will need. Bet it never goes as well again though
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Prezactly. The disc-valve Rotax was the same. That usually went as a
result of the ignition charging coil dying slowly and putting the timing
miles out though. TBF it gave me a bit of warning a couple of times, but
as by then the red mist had descended, with only a lap to go and holding
a decent position it tended to be ignored with the inevitable
consequences.

I suppose we ought to define 'holed' more precisely. Are you expecting
an actual orifice or a melted leading edge of the crown area?

Hah! Have you ever seen the inside of a Husky 510 after dropping the
head off a valve?

--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Pete Fisher says...

Oops.

<of Pug 306XLDs or GFR125s>

It's fucked mate, I'll give you a tenner for it.


--
Lozzo
Triumph Daytona 955i SE
Suzuki SV650 K3
Honda CBR600 F-W
Suzuki GSX-R750L
Yamaha SR250 SpazzTrakka

 

Pete Fisher says...

The plug is too clean. An absloute absence of oil on it leads me to
believe it has nipped up through a lack of lubrication. You always get
blackish oil deposits on the flat ring around the base of the threads,
yours has none. That's run dry of oil, I'll bet.

--
Lozzo
Triumph Daytona 955i SE
Suzuki SV650 K3
Honda CBR600 F-W
Suzuki GSX-R750L
Yamaha SR250 SpazzTrakka

 

Hmm. It is a bit shiny compared to the one in high miler. In fact a C55C
is apparently OEM according to the pristine glossy owners book. I always
run a B10EGV in the other one.

Definitely oil (TTS) in the oil receptacle. I had to top it up after the
first short run after getting it home a couple of weeks ago. Seems to
have used some and the warning light goes off when in gear as it should.
Suppose it could be a twatted or maladjusted pump. Smokes when first
started, but clears quicker than the other, but I put that down to the
old one being a bit loose.

Possibly a problem with oil reaching the pump. Certainly no air in the
system as there was oil in the tank when I topped it up, and I had
wazzed it up to the red in the intermediate gears a few times already
without anything nasty happening.

Will check the oil line and pump delivery.

I did reluctantly have to fill up with UK plonk petrol as the station I
expected to fill up with super-unleaded at had been flattened to build
houses.

Oh well. It will keep me out of mischief as winter draws on.
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Heh! Even the pug is worth more than that for the tyres and battery
alone.
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Looks ok to me. Do these two pages help:
http://www.mztech.fsnet.co.uk/workshop/wrk_plugs.html
http://www.mztech.fsnet.co.uk/workshop/wrk_piston.html

 

Now when it comes to exploded two strokes and you I'm not one to argue
but I always worked on the basis that lack of lubrication took out
bearings and heat (ignition) took out pistons.

 

Thanks. It is remarkably clean looking though. Mind you, it was getting
a fairly bracing dealer's decoke at the time.

The little of the piston crown I can see through the plug hole looks
possibly unnaturally clean as well, but no sign of debris or pitting.

I am reluctant to strip it down unless absolutely certain it is a
compression failure of some kind. I could do with getting hold of a sort
of endoscope to have a look inside.

Any idea what kind of compression reading I should expect from a 12.5 CR
125?

--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Probably looks just like a BMW.

http://uk.pg.photos.yahoo.com/ph/ukrmplatypus/detail?.dir=1990&.dnm=3164.jpg&.src=ph
http://uk.pg.photos.yahoo.com/ph/ukrmplatypus/detail?.dir=1990&.dnm=ee5c.jpg&.src=ph

 

Ouch. The Husky needed new valves and springs, pressed in cylinder liner
and piston plus a cam chain. A tired cam chain and valve springs
apparently being the reason for failure (though the missed gear change
might have been a factor).

I still have the '29 Raleigh valve that dropped from the collet groove,
glued to the piston it made a neat crescent moon slot in, as a memento.
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Some oil pumps, certainly those on Yamahas, need bleeding if they've
been dismantled. I've also heard of the wrong oil being used or the
oil tank being topped up with a mismatched oil, so they can supposedly
gum up, though I think that's limited to vegetable/mineral mixes,
which is unlikely these days.

 

In communiqué <>, Pip Luscher

No knowledge of any dismantling, and the seller (who seemed trustworthy
enough) had been running it on full synthetic and had been riding it
(gently perhaps) with no problem.

I topped it up with TTS before the run. I would have thought if there
had been a major problem like an air lock it would have shown up
earlier. IME with the other one any reasonably decent 2T oil seems OK
even mixed.

The problem is that the other one seems so bullet proof that I was
lulled in to a false sense of security.

Needless to say if it was a zero oil supply from pump event then the
mains etc. are going to need checking. I am not ruling out perming 1
from 2 to get the best combination of trusted motor and shiny bodywork
etc. That still would leave me with a lot of GFR unobtainium. An almost
identical motor has been used in many Gilera 125s so I should be able to
source a cylinder and piston - at a price.


--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Have you actually posted a picture of this beast somewhere?

Just curious.

 

That must qualify in a short list for the longest URL ever award.

That's the machine in question, except that on this particular example
the pretty bodywork is currently piled in one corner of the garage, and
the motor sits forlornly in an other.

As a result of a bout of very unpleasant lurgy I haven't got any further
with it yet. Hoping to catch Uncle Bob Wright on the phone later, but
his apprentice (who only really knows about the Runners and DNAs etc.)
confirmed that it has a nikasil bore. This almost certainly means
re-plating as suggested by Lozzo and matching to a new piston, or, more
expensive but less error prone, a new matching barrel and piston (4
minutely differing bore variants).


--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

So no new barrels for GFRs Should be possible to re-plate though
(Bob gets them done at Langcourt in Weston Super Mare). New piston and
gaskets are in stock.

Revs are going to have a look when I can get the motor over to them.

--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+

 

Ta. My quick chat with John at Revs made it sound something they got
done quite often ,so they obviously have somewhere in mind.

I see from their web site that they also do 2T tuning. On second
thoughts...
--

+-------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster Gilera Nordwest Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 |
+-------------------------------------------------------------+