Irregular Piston Wear Series 2 180
- Thread starter GT
- Start date
Probably bent and/or twisted conrod, Glenn.
Is there a bright/light coloured patch at the top land opposite to the skirt wear? I think I can detect the edge of a bright spot in the pic.
Very common I'm afraid, but not often as bad as in your example. If the conrod checks out OK, the big end could be at fault, either wacky or on the way out. Seen that before too.
Looks like your pistons are past their best anyway.
And you lifted head and barrel with the engine in the frame, get set to be flamed for that!
piet
Is there a bright/light coloured patch at the top land opposite to the skirt wear? I think I can detect the edge of a bright spot in the pic.
Very common I'm afraid, but not often as bad as in your example. If the conrod checks out OK, the big end could be at fault, either wacky or on the way out. Seen that before too.
Looks like your pistons are past their best anyway.
And you lifted head and barrel with the engine in the frame, get set to be flamed for that!
piet
laverdakeith
Hero member
How about that, second opinion is exactly the same as the first, even down to the method of disasembly 
Keith
Keith
Rusty Spokes
Hero member
- Location
- Decatur, Ga. USA
Mic the bore too. Could be the rod or a poor/out of position rebore/out of round cylinder.
Has the engine got the stock standard pistons or 1st/2nd oversize?
Has the engine got the stock standard pistons or 1st/2nd oversize?
Rusty Spokes said:
Yes, have had that too, sadly. Blew oil out the breather as soon as the revs hit 6000 and the rings no longer managed to seat decently, had me puzzled till I went to next oversize and the barrels bored out properly, all fine then!
piet
CLEMTOG
Hero member
I once saw an engine (triple) in frame with the head off and all the studs still in place,The owner tried telling me that he had removed the head and did not need to pull any studs !!. I know that engine got installed minus its head, its not magic and he was not Paul Daniels.
CLEM
CLEM
Rufustbear
Hero member
- Location
- Manchester
You only have to remove one stud,its quicker than takeing the engine out
laverdakeith
Hero member
Rufustbear said:
Not when you come to put it all back together again its not.
Keith.
Rufustbear
Hero member
- Location
- Manchester
Well whats one stud less, here or there 
Tippie
Hero member
- Location
- Dr?bak, Norway
A badly aligned re-bore cost me an SF crankshaft. After a couple of thousand miles a piston had melted from the side as a result, and new sleeves/pistons were fitted and all was ok. Many thousands of miles later it was discovered that the time with the misaligned bore had caused the conrod to side-thrust into the crank, wearing into the flywheel several mm and the rod was stuffed. Lovely.
I later had a mate with a re-bore from the same place (supposed to be the best in Melbourne) which seized, then freed up, on its first ride. Checked and it was up to .008" out with measurements all over the place, conical, crooked etc.
It pays to find someone good and stick to them.
I later had a mate with a re-bore from the same place (supposed to be the best in Melbourne) which seized, then freed up, on its first ride. Checked and it was up to .008" out with measurements all over the place, conical, crooked etc.
It pays to find someone good and stick to them.
motoddrob
Hero member
- Location
- S/W Australia
"I later had a mate with a re-bore from the same place (supposed to be the best in Melbourne) which seized, then freed up, on its first ride. Checked and it was up to .008" out with measurements all over the place, conical, crooked etc."
Think that was me Lee. Got half way up the Dandenongs when it seized on it's first outing. Once cooled down I was able to ride it home. Got a new set of pistons and sleeves from the guy and he sorted it.
Think that was me Lee. Got half way up the Dandenongs when it seized on it's first outing. Once cooled down I was able to ride it home. Got a new set of pistons and sleeves from the guy and he sorted it.
Tippie said:
How bloody true!
The one and the same guy has been doing my rebores for the past 25 years! Never had the slightest issue, compared to the very renowned shop that had my custom before that. Shagged my 3C head big time, honed the barrels crooked. Were supposedly BMW experts, probably all they were good at... now long out of business!
piet
phil37
Hero member
- Location
- Lincolnshire
Seen loads like that Clem - they can be found on Saxon/Motodd framed triples!
I used to do all my rebores with my massive honing machine! - Regards and happy new year - Phil
CLEMTOG
Hero member
ha ha Phil, ever the saleman eh?
your joke might be missed by a few who dont realise that one of your design criteria, for the frame kit was to enable easy, in situ head removal.
I have even seen a frame with a hole drilled i n it to ease getting a stud out
Just hook the motor out for god's sake, if you are doing this in situ, you will allready have removed the carbs and the exhaust,plus other sundries so the only things holding the motor in place are a few bolts, some very easy wiring, and the drive chain, dont forghet the neutral light wire.
It is eevn worse if you are doing a 750 in situ, because you will have released everything except two bolts, so that you can hinge the motor down, that is even more daft.
CLEM
your joke might be missed by a few who dont realise that one of your design criteria, for the frame kit was to enable easy, in situ head removal.
I have even seen a frame with a hole drilled i n it to ease getting a stud out
Just hook the motor out for god's sake, if you are doing this in situ, you will allready have removed the carbs and the exhaust,plus other sundries so the only things holding the motor in place are a few bolts, some very easy wiring, and the drive chain, dont forghet the neutral light wire.
It is eevn worse if you are doing a 750 in situ, because you will have released everything except two bolts, so that you can hinge the motor down, that is even more daft.
CLEM