Crank Question

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Tambo
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Crank Question

Post by Tambo » Thu Jan 17, 2013 10:08 am

Hi folks,

Busy end to the year meant little bike time, and even less forum time since completing the build on my C3 :oops:

Engine was built with a fresh crank, and felt and sounded 'normal' during a brief gentle road test. Shortly after that, the stator failed, and in my impatience to locate my flywheel holder, I put it into gear, and stood on the brake to attempt to loosen the flywheel bolt :shock: :oops:

Anyway, that didn't work, so removed the flywheel properly, and replaced the stator with an earlier version.

Bike starts and runs, but refuses to pull, and there is a whine that wasn't there before. Timing is correct, and there is no misfire at all. The engine just feels tight.

I suspect in my hurry to remove the flywheel bolt, I may have twisted the crank, therefore tightening up the centre bearings ???

Any thoughts ?

Thanks,

Tommy
Kr1s c3, vfr750fg, Dnepr MT11, Pegaso 650

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daz680
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Post by daz680 » Thu Jan 17, 2013 10:44 am

Going by your discription on how you first attempted to remove the bolt if you consider the crank being locked via the rh side through the gearbox i think there may be a possibility that you've twisted your crank but the only way to confirm it is to remove the crank and have it clocked.
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Tambo
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Post by Tambo » Mon Jan 21, 2013 5:47 pm

I'm pretty sure that's what's happened :cry:
I'll try accurately measuring down the plug hole to see if there's a difference, but in reality I think it'll be engine out again !!
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500bernie
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Post by 500bernie » Mon Jan 21, 2013 6:23 pm

Bad luck Tommy.
That sounds like something I would do ](*,)
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Tambo
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Post by Tambo » Mon Jan 21, 2013 8:24 pm

Impatience got the better of me Bernie !! I'd only cut up the old flywheel holder to make something else a couple of weeks before [-X
Ho humm, I'll not do that again :roll:

Was a fresh crank built by Grampian through a trade mate - who would you guys recommend I send it to ?
Given that it's already been re-built with the original centre, do you think it'll need a new centre ?
Can the fresh conrod kits be re-used (only done 20 miles) ?
I'm presuming the mains and seals will need replaced again ?

What's your thoughts folks ?

Tommy
Kr1s c3, vfr750fg, Dnepr MT11, Pegaso 650

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Post by fred » Mon Jan 21, 2013 8:39 pm

ime no expert but i would of thought a firm that does cranks would true it as it is stated in the manual without stripping it appart

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Post by JanBros » Mon Jan 21, 2013 10:39 pm

fred wrote:ime no expert but i would of thought a firm that does cranks would true it as it is stated in the manual without stripping it appart
I agree, no need to take it apart.
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Tambo
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Post by Tambo » Fri Jan 25, 2013 12:22 pm

That sounds promising guys 8)

I take it my hamfistedness sounds like the reason for the whining and tight engine ? As i say, otherwise only the stator was changed, and seemed fine (other than cutting out).

Any suggestions for who to send the crank to for checking / straightening ?

Thanks,

Tommy
Kr1s c3, vfr750fg, Dnepr MT11, Pegaso 650

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500bernie
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Post by 500bernie » Fri Jan 25, 2013 2:58 pm

Hi Tommy

Get it back in to Grampian, they should be able to sort it.
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Tambo
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Re: Crank Question

Post by Tambo » Thu Jun 06, 2013 4:45 pm

Been busy with work for a wee while, but finally got my crank out, and straightened for £20 from a semi-retired racer / engine builder in Fife 8)

While it was stripped, also sent my pretty tired barrels to Lancourt for re-plating. Just need a wee bit of time to get it all together again :mrgreen:

How did it become June already ?? :roll:
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500bernie
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Re: Crank Question

Post by 500bernie » Thu Jun 06, 2013 5:46 pm

Tambo wrote:Been busy with work for a wee while, but finally got my crank out, and straightened for £20 from a semi-retired racer / engine builder in Fife 8)

While it was stripped, also sent my pretty tired barrels to Lancourt for re-plating. Just need a wee bit of time to get it all together again :mrgreen:

How did it become June already ?? :roll:
How did it become 2013 already :(
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Re: Crank Question

Post by Top-shaggy » Thu Jun 06, 2013 9:33 pm

O.M.G it's nearly summer... But don't blink, because you may miss it :wink:
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Re: Crank Question

Post by banditbob » Fri Jun 07, 2013 6:57 pm

Hi Tommy I am in fife who was the chap who did your crank may come in use some time .cheers bob.

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Re: Crank Question

Post by Professor » Tue Jun 11, 2013 12:43 am

Service Exchange Parts should be good, although I've not used them recently. They used to keep KR1S crank bearings and seals in stock.

Would BDK do them? them make the crank centre.

Must check the alignment of my crank as there is a little bit of vibration, does anyone think that the crank webs are matched pairs? I changed one of the webs on mine and couldn't get it perfectly aligned!
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