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Post by headcoats on Jul 4, 2021 15:52:08 GMT 1
Been chasing a noise on the yellow hybrid with YPVS engine
Gone through 3 sets of primary gears and still same noise, so this weekend I have stripped the motor completely to try and get to the bottom of it
Noise seemed to be coming from back of engine ,as in gearbox but all seems ok All new genuine bearings were used and I had built the bottom end several years ago then stored it and used this for this build
Crank was a P J Engineering rebuild too
Going to get barrels properly checked but wasn't a top end noise
So what do I need to go through as it's doing my head in LOL
Red LC Hybrid on the other hand that was built about 10 years a go sounds great in comparison
Need a crystal ball here ... |
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Post by davecroucher57v on Jul 4, 2021 17:25:09 GMT 1
kickstart idler.
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Post by headcoats on Jul 4, 2021 18:38:22 GMT 1
It had a brand new idler gear ,so was not sloppy
I was thinking the mechanical tacho gear but ran it with the little cog removed just to see , but wasn't that
Looks like it's going on sorn LOL
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Post by wallcraft on Jul 4, 2021 21:24:57 GMT 1
What kind of noise, whine, ticking, rattle, scraping, rubbing ?
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Post by headcoats on Jul 4, 2021 21:34:39 GMT 1
It was like something was catching as it was running
Stripped right down now
Gonna make a paperweight LOL
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Post by chrisg on Jul 5, 2021 4:36:43 GMT 1
Gearbox related? Selector forks ?
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Post by headcoats on Jul 5, 2021 7:03:36 GMT 1
I'm convinced it is gearbox but who knows!
The selector forks all look good with no scoring or heat Mark's etc
This is happening at idle too,so bike is in neutral
No gear whine
No chipped teeth
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Post by headcoats on Jul 5, 2021 8:00:16 GMT 1
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Post by chrisg on Jul 5, 2021 9:52:50 GMT 1
Are all the selector forks the same or is it possible to inadvertently swap them.?
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Post by headcoats on Jul 5, 2021 10:42:29 GMT 1
2 are the same out of the three and did check that
The little bracket that holds the mechanical tacho shaft in place has a little wear and possible noise ?,
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Post by ianboom on Jul 5, 2021 11:04:03 GMT 1
Shame you didn't leave the engine in the bike and strip it back as far as possible, then run it to see if the noise is still there.
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Post by headcoats on Jul 5, 2021 11:28:17 GMT 1
Yes it's a right booga and to put it back together and get the same noise, I will sell up and become a monk LOL
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Post by headcoats on Jul 5, 2021 17:18:58 GMT 1
I have a spare gearbox , well 2 and the one in the bike is the better one
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Post by chrisg on Jul 5, 2021 22:58:12 GMT 1
Is the clutch shaft bearing keeper plate fitted? Has the clutch basket been apart and have loose rivets? Just my thoughts.
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Post by headcoats on Jul 6, 2021 6:58:16 GMT 1
I fitted a mitaka clutch basket with new cush rubbers which was the last roll of the dice to try before I stripped it
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Post by chrisg on Jul 6, 2021 10:42:42 GMT 1
I fitted a mitaka clutch basket with new cush rubbers which was the last roll of the dice to try before I stripped it
Are there any parts that have shiney or rub marks, I'm sure you've probably looked. Very Puzzling. |
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Post by headcoats on Jul 6, 2021 11:14:02 GMT 1
Taking crank and barrels to P J Engineering for a look but that still leaves other areas that was making the noise ,unless the noise was travelling
You open the cases and it's just a crank and 2 rows of gears, what's not to spot LOL
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Post by Robbieben on Jul 6, 2021 12:05:12 GMT 1
I once had a primary shaft bearing that used to tick as the engine ticked over, (I didn't know it was at the time), stripped the engine, couldn't find any faults with the bearings turning them by hand, put new bearings in the gearbox and it cured it, I then opened up each bearing and found one ball with a wear flatspot on it. May be a similar issue you have??
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Post by headcoats on Jul 6, 2021 12:08:49 GMT 1
Was that the double row bearing behind the clutch Robbie
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Post by Robbieben on Jul 6, 2021 12:19:32 GMT 1
Was that the double row bearing behind the clutch Robbie Yes, it was the mainshaft bearing with the locating groove in. |
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Post by headcoats on Jul 6, 2021 13:18:53 GMT 1
The expensive one !
New bearings about 700 miles ago and genuine but I guess worth changing just in case as I don't want to strip again
My noise is more than a tick though
I have the engine noise on my watsap so don't know if they could put it on here for me , Ta :-)
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Post by headcoats on Jul 6, 2021 13:26:48 GMT 1
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Post by Robbieben on Jul 6, 2021 13:39:07 GMT 1
LC Part No is 93305-20502. It was an old RD250 but not a great deal changed over the years on them, i'm more making suggestions than anything, sometimes these things are bloomin hard to track down and crankcases are great at misleading you to where a noise is coming from, I have a stethascope and it helps but still isn't perfect. |
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Post by wallcraft on Jul 6, 2021 16:57:47 GMT 1
If it made the noise with the Athena top end on then you can discount the PV top end. You've probably worked that out though.
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Post by wallcraft on Jul 6, 2021 16:59:09 GMT 1
Burr on the primaries ?
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Post by davecroucher57v on Jul 6, 2021 19:14:44 GMT 1
is it the same with the clutch pulled in.
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Post by headcoats on Jul 6, 2021 20:02:37 GMT 1
Yes clutch in or out same noise
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Post by Chewie01 on Jul 6, 2021 20:20:18 GMT 1
That should mean it's not coming from the gear box
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Post by chrisg on Jul 7, 2021 15:31:01 GMT 1
Water pump? Running out of components to name  Maybe build back up and try to listen with screwdriver placed in various areas and listen to the end. No joke, It does work. I built a 250e some years ago (new crank etc.) and it sounded like the big end had gone. After many hours of head scratching it ended up the crank pinion gear and the clutch gear were not matched and made the knocking sound, but you would have never known to look at them. |
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Post by headcoats on Jul 7, 2021 16:13:45 GMT 1
Water pump was rebuilt LOL
Had barrels looked at today and are out of spec so rebore is needed but he said it wouldn't make the noise I'm getting !
Will get them rebored I promise !
Where is best place to get pistons, anyone got some Mitakas at 1.00mm over
Like you say I will just have to start from scratch or put some sawdust in the gearbox !
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