chrisk
Drag-strip hero
Posts: 281 
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Post by chrisk on Jan 12, 2019 17:54:42 GMT 1
Just out of interest, how many miles have folk got out of a crank.
Before seals, mains, or rods were toast.
Ta chris.
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Post by steeley on Jan 12, 2019 18:27:23 GMT 1
Hi I had 50,000 plus on one in the lc . Then there are folks who change one every year .
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Post by midlifecrisisrd on Jan 12, 2019 18:27:45 GMT 1
I've opened 2 now that were on original bore and 1 definitely not opened before
Both had wear but still in one piece (well one was, the other had a bent rod due to hydraulic locking)
Think 20 - 30k miles was expected for a new original crank that wasn't abused
Even the 500's would do 20k before munching the mains
Steve
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chrisk
Drag-strip hero
Posts: 281
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Post by chrisk on Jan 12, 2019 18:31:10 GMT 1
Hi I had 50,000 plus on one in the lc . Then there are folks who change one every year . That's very impressive. Was it a 250. And how did it sound/perform. Ta chris |
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Post by Tobyjugs on Jan 12, 2019 20:38:13 GMT 1
Nice topic Chrisk
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Post by Mr Kipling on Jan 12, 2019 20:48:36 GMT 1
one of my P/V,s did 19,000 before I sold it....
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Post by headcoats on Jan 12, 2019 20:54:47 GMT 1
If it had 500 miles on it and was left in a damp shed for years then it would be f##ked
I guess used regularly is the question here
So many things to throw in like is it tuned , do you rev it to 10K plus every ride out etc
I would hope more than 20K
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Post by dusty350 on Jan 12, 2019 20:58:10 GMT 1
The F2 engine that is in my orange hybrid had 22000 miles on standard bore and crank, and looked pretty good condition. Bike had been all standard I believe. Dusty  |
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Post by Tobyjugs on Jan 12, 2019 21:27:11 GMT 1
If it had 500 miles on it and was left in a damp shed for years then it would be f##ked I guess used regularly is the question here So many things to throw in like is it tuned , do you rev it to 10K plus every ride out etc I would hope more than 20K Not necessarily a problem to store if you put a little thought into it. You could fill the crank space up with two stroke oil, or some Ensis engine oil 30 which is used for storing or flushing engines and gearboxes out after they have been badly contaminated with water (filled up)  |
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Post by JonW on Jan 12, 2019 23:36:47 GMT 1
In Aus they seem to last 20-30k kms in standard bikes. Ive found plenty of rough bikes with blow engines ate multiples of those kms.
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Post by midlifecrisisrd on Jan 13, 2019 0:12:05 GMT 1
When I bought my lc2 first time round it had 15k on it so original crank
I ran it till just under 20k the n stripped the top end off as pc's were leaking and the bike was getting it's first rebuild
Already on 0.5 bore. Sent it to Stan for a stage 2 tune and pv tunnels reserved
Bores and pistons were fine so went back together
Did about 1000 miles then sold it
It shat itself a week later
Steve
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Post by jon on Jan 13, 2019 11:02:57 GMT 1
My first powervalve was taken apart at 20k
Both crank and bores would have done a bit more, but as they were starting to look tired were re-done. I didn’t really want to be taking it apart again in the near future.
Jon
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Post by earthman on Jan 13, 2019 11:36:36 GMT 1
I wonder what the official answer from Yamaha would have been back in the day?
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Post by jon on Jan 13, 2019 12:43:21 GMT 1
I wonder what the official answer from Yamaha would have been back in the day? Why don’t you ask them then? They’ve probably got historic data. He’ll, I might even ask them what the biggest oversize piston they made as consensus is 0.5mm. Jon |
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Post by earthman on Jan 13, 2019 15:56:23 GMT 1
I wonder what the official answer from Yamaha would have been back in the day? Why don’t you ask them then? They’ve probably got historic data. He’ll, I might even ask them what the biggest oversize piston they made as consensus is 0.5mm. Jon I don't know any of their contact details or have a way in as so to speak,...maybe one of the 'official' clubs would have? If you know of a way in, by all means, feel free to have a go yourself. |
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Post by mikee on Jan 13, 2019 16:36:06 GMT 1
I wonder what the official answer from Yamaha would have been back in the day? Why don’t you ask them then? They’ve probably got historic data. He’ll, I might even ask them what the biggest oversize piston they made as consensus is 0.5mm. Jon They used to do a 2mm oversize piston Mike |
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Post by bare on Jan 13, 2019 19:14:36 GMT 1
I wonder what the official answer from Yamaha would have been back in the day? Why don’t you ask them then? They’ve probably got historic data. He’ll, I might even ask them what the biggest oversize piston they made as consensus is 0.5mm. Jon Interesting thought.. But those people don't even release accurate Number of units sold 30+ years ago. Diesel filling the crankcase is an easy harmless rust preventative. Dunno How you would get it out tho :-) |
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Post by earthman on Jan 13, 2019 20:36:24 GMT 1
Why don’t you ask them then? They’ve probably got historic data. He’ll, I might even ask them what the biggest oversize piston they made as consensus is 0.5mm. Jon Interesting thought.. But those people don't even release accurate Number of units sold 30+ years ago. Diesel filling the crankcase is an easy harmless rust preventative. Dunno How you would get it out tho :-) I were thinking more along the lines of being able to obtain information from what would have been the 'engine design department' back then, the guys who would have done the R&D and testing of this engine, maybe they would have a rather more accurate idea on lifespan. |
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Post by midlifecrisisrd on Jan 13, 2019 20:58:11 GMT 1
The old data is irrelevant now as it was all on 80's sh1t oil
Steve
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Post by earthman on Jan 13, 2019 21:31:48 GMT 1
The old data is irrelevant now as it was all on 80's sh1t oil Steve Good point but it would still be a good 'base line' to go from. |
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Post by steeley on Jan 13, 2019 21:56:35 GMT 1
Hi I had 50,000 plus on one in the lc . Then there are folks who change one every year . That's very impressive. Was it a 250. And how did it sound/perform. Ta chris Hi it is a 350lc, at the time it had a Bob Farnham F2 tune .I ran it on fully synthetic 2 stroke oil and it sounded like a swiss watch and ran well . In the end a main bearing went. This was due to my own careless reassembly after fitting new gearbox bearings. years ago I was talking to a chap at Armstrong Engineering and he said you could get 30,000 out of one. |
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Post by midlifecrisisrd on Jan 13, 2019 22:20:03 GMT 1
The 30k figure is probably a good mileage if treated well
Both high mile cranks I had (27k and 29k) although in good order had loose mains and the big end side clarance rod deflection were just within service limits
I did have a one owner 350R that was used for commuting which had 62k on the engine
I have now idea if the bottom end had been split as I never opened it so couldn't see sealant on the crank cases or previous clean ups but it was only on 0.5 over
Steve
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Post by Norbo on Jan 14, 2019 15:37:04 GMT 1
It depends on the mixture . you can have a brand new crank and it toast after a few hundred miles if its running week but if everything is running fine you should get 10s of thousands out of 1 . My F2 was running mint and i did thousands of miles on it thrashing the crap out of it 4 or 5 times a week and it never let go , I still have the bike now not road it for many many years but for several years it was my main bike and i must have done a good 30 to 35K on that bike 80% of that would have been hard thrash .
So the answer is depends on the oil you use and the mixture .
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Post by bare on Jan 18, 2019 2:14:52 GMT 1
The old data is irrelevant now as it was all on 80's sh1t oil Steve OK..The oils of back then..stuff that Yama ran and won world championships with... in these bikes .. Now isn't Good 'nuff ? Barking up the wrong tree on that IMO |
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Post by doohanno1 on Jan 18, 2019 8:52:34 GMT 1
The old data is irrelevant now as it was all on 80's sh1t oil Steve OK..The oils of back then..stuff that Yama ran and won world championships with... in these bikes .. Now isn't Good 'nuff ? Barking up the wrong tree on that IMO Eh, bit of a difference between championship mileage and road mileage |
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Post by midlifecrisisrd on Jan 18, 2019 10:17:01 GMT 1
The old data is irrelevant now as it was all on 80's sh1t oil Steve OK..The oils of back then..stuff that Yama ran and won world championships with... in these bikes .. Now isn't Good 'nuff ? Barking up the wrong tree on that IMO Hmm, where do I start? Race bikes a little different, they certainly weren't using 80's Yamalube Seriously doubt a race bike got 30k miles out a crank World Championships slightly different from the local ring road championship Race bikes regularly stripped and checked within a thou of their lives, other than an oil change road bikes only came apart when they HAD to. I don't see a carbon build up to cause problems in my bike now Finally if 80's oils were so good how come I can't find Duckhams Blue in my local filling station anymore Unless the Yanks kept all the good stuff over there and sent us the pish Steve |
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