Coo, that's running rough

Erm, except that the mix will be on the *other* side. Doh.

OK, so how do you detect a shot seal on the 'dry' side?

 

On 31 Aug 2005 02:55:00 -0700, "TOG@Toil

From the deluge of posts while you were elsewhere, *everything*.
--
| ___ Salad Dodger
|/ \
_/_____\_ GL1500SE-V/CBR1100XX-X/CBX1000Z
|_\_____/_| ..78868.../...19540.../..30836.
(>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 YTC#4
|__|_|__| BOTAFOT #70 BOTAFOF #09 two#11
\ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4
\|^|/ ANORAK#17 IbB#4 PM#5 WG*
'^' RBR Clues: 29 Pts: 485 Miles: 1967

 

The Older Gentleman says...

One squirts carb cleaner onto the suspected area as the bike ticks over
at a steady rpm and watches the revs rise as it gets sucked in.

If you have an incredibly difficult job to do, give it to the laziest
fucker you know. He'll find a quick and easy solution.

 

Hmmmmmm.....

OK, I feel an obligation of some sort here, seeing as I sold it, and
never mind that it was running perfectly when it was sold.

If it is indeed the crank seal, I'll cough for new seal(s); for the
part(s). And Ivan, you can find somebody (Lozzo?) to help you pull the
lump apart and reassemble. It's a 2-stroke single, so they don't come
any simpler. And I threw in a brand new unused full gasket kit with it,
ISTR.

I'd like an expert assessment (Lozzo?) to say that it *is* the seals,
mind. It's possible, seeing as it had been stored for over 20 years:
they could have dried out.

But, Ivan, if you've ballsed something up yourself, you're on your own,
sunshine ;-))

Who thinks that's fair?

 

And if the bike refuses to tick over.....?

 

The Older Gentleman wrote

I think you are being more than fair. Although once it transpires
exactly what is wrong one way or the other we expect suitably grovelling
apologies from the offending party.

 

Heh. Well, by offering, I've already started the grovelling apology
process.

You're not hinting that Ivan's buggered it up himself, are you? ;-)

 

The Older Gentleman wrote

It don't matter what I am hinting at. I simply cannot allow my mind to
consider the potential consequences that can arise from a bloke with his
fingers on some of the buttons that Ivan has his fingers on given that
he has had so much trouble with one of the world's simplest machines.

Scary.

 

Yeah, I had a crank seal on a DT125 work out of position and though
the engine did run at first, it would barely start and could hardly
idle at all. It eventually died a few minutes later because of all the
crap being blown onto the points.

 

ISTR that you're right.

 

Personally, I wouldn't expect it to. The airflow at idle speeds with
the throttle shut will be miniscule compared to the airflow with WOT
at max. BMEP, so the pressure drop across a filter under those
circumstances will be equally miniscule.

Seals or reed would be my guess. Try checking the primary compression
- see how much suction/bllowback there is through the carb or the
mounting rubber itself. With the plug out there should be a distinct
"chuff" as the piston clears the transfer ports as it's kicked over
too.

 

The Older Gentleman says...

It will but at higher revs, it'll just run much higher in short bursts
when you spray the carb cleaner onto the seal area. You could rev it and
then spray the cleaner on, and watch the revs rise when they should be
falling.

 

The Older Gentleman says...

I would be very surprised if the left crank seal isn't fubarred. It was
sitting unused for 20 years, that's way too long to expect it to stay
airtight once it starts being run on a daily basis. The wear rate will
be phenomenal once it starts to go, leading to exactly the problems Ivan
has now.

 

by offering, I've already started the grovelling apology

Very true.

 

If it's burning hypoid (which it shouldn't be as the DT gearbox uses
engine oil IIRC) there'll be a smell loosely similar to frying onions.

 

You buggers are lucky I'm on a course in Oxfordshire and can't access
my computers...

--
Ivan Reid, Electronic & Computer Engineering, ___ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD, DT175MX "You Porsche. Me pass!" DoD #484 JKLO# 003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

I "actively" noticed its revving high on the first trip I took it
on after I got it home, out here to RAL in Oxfordshire. The dying incident
was coming back from the same trip the next day. Up to then I'd touched
nothing but the fuel tank and the oil tank (on the second day), except for
checking the battery IIRC.

After the dying incident I gave it a new plug, and cleaned the carb
and checked the reeds. I then gave the carb a more thorough going-over when
I had the manual and the Mikuni handbook. I did subsequently change the oil
and look at the oil pump -- and I do mean "look"! ...and replace the bodged
air cleaner. It then got me to Adie's party and back, with some difficulty
starting in Bedford and the usual high idle when warm.

You'll keep! But you're right, google groups documents it all.

--
Ivan Reid, Electronic & Computer Engineering, ___ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD, DT175MX "You Porsche. Me pass!" DoD #484 JKLO# 003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

OK, I've had a look. I was on holiday while this was going on and
didn't play catch-up with Usenet when I got back.

Interesting. I'm coming to the conclusion that Lozzo is right - it
looks like a crank seal has dried out because it stood for so long, and
so it ran absolutely perfectly for long enough for the seal to nadger.

Incidentally, poking bits of wire down jets and orifices in
carburettors is *not* a clever thing to do :-0 You can easily enlarge
the jet holes etc, and then you're buggered. Even with copper wire -
carb internals are very soft and easily damaged.

I don't think there's anything else it really can be. So get an expert
opinion, and if it is the seal(s), like I said, I'll cough for the
part(s). You're probably better off replacing both seals on the "might
as well" basis. Once that's sorted, it will be lovely again.

 

I did this once with an old (1976) RD250 - swapped L & R and put them in
the wrong way round. It ran very strangely...