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Author Topic: New to listers, is a knock normal?  (Read 8257 times)

dieselgman

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Re: New to listers, is a knock normal?
« Reply #15 on: September 22, 2017, 12:30:46 AM »
I took a video of it, I'm not sure I f youll be able to tell or not.  but here it is.

https://youtu.be/7Sodulxo0-c
That sounded fairly normal to me... but how much can you tell on a computer laptop speaker? If your machine starts easily and the exhaust is clean and clear, you are probably pretty close to proper timing already. Your valve lash will have quite a bit of impact on overall performance and noise levels as well - worth taking a close look at.

dieselgman
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ronmar

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Re: New to listers, is a knock normal?
« Reply #16 on: September 22, 2017, 04:08:25 AM »
Yea, that sounds pretty good to me also...  Was that loaded or unloaded?
PS 6/1 - ST-5.

BruceM

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Re: New to listers, is a knock normal?
« Reply #17 on: September 22, 2017, 05:45:53 AM »
Sounds about right for a CS under a bare tin roof.

carlb23

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Re: New to listers, is a knock normal?
« Reply #18 on: September 22, 2017, 12:13:36 PM »
plastigauge is the way to go.  It will tell you want the clearance is and give you an opportunity to inspect the rod bearing and the crank pin.   

thinder

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Re: New to listers, is a knock normal?
« Reply #19 on: September 22, 2017, 07:40:02 PM »
Yea, that sounds pretty good to me also...  Was that loaded or unloaded?



Unloaded, just a single LED bulb running.

SHIPCHIEF

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Re: New to listers, is a knock normal?
« Reply #20 on: September 23, 2017, 05:08:12 AM »
It looks a little twitchy, but it sounds OK to me...
Dropping the connecting rod cap and taking a plasti-gage reading is pretty easy. It will help you get familiar with working on one of these engines. You are probably OK, but hear me now: it's better to inspect before failure than to discover after failure.
Th up-side of these engines and ST generator heads is: you can work on them. The down side is that you have to work on them. You must futz around and inspect / tweek / 'fettle' as they say in England.
If you are good with that, then you have a good 'Post Holocaust' generator that will serve you well.
I have a Ashwamegh "25/2" that had to be completely disassembled, the block hot tanked and needle scaled, the crankshaft polished and everything hand fitted on re-assembly. I'm pretty sure I 'know' my engine now. I've stocked up on bronze idler gear, offset idler gear bolt, spare gaskets and fuel system parts etc. that were offered when this site was very active and special parts were being made and offered by the outstanding members.
This site is a little quieter now, but still 'top notch'. If you keep at it, you will become one of the senior members, and carry the torch for the next generation.
Ashwamegh 25/2 & ST12
Lister SR2 10Kw 'Long Edurance' genset on a 10 gallon sump/skid,
Onan 6.5NH in an old Jeager Compressor trailer and a few CCK's

Quinnf

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Re: New to listers, is a knock normal?
« Reply #21 on: September 24, 2017, 06:02:49 AM »
What you describe sounds exactly like what I ultimately found was a loose fitting gib key.  I can't hear it in your video, but the sound in mine sounded like it was coming from the crankcase.  I found on my PowerSolutions 6/1 that the gib keys were narrower than the slot milled in both the crankshaft and the flywheel.  Total clearance was about 0.019" if I recall correctly.  No matter how tight I pounded the gib keys in, on power strokes, there was enough torque to twist the crankshaft against the flywheel, and when it came up tight, it made a "clunk" sound that went away immediately when the decompressor lever was engaged.  Do yourself a favor and before you go tearing the big end off the rod, pull a gib key and measure the width, then measure the corresponding width of the slot in the crankshaft.  They should be within a thousandth or so.

I fixed the clearance by taking some pieces of 0.005 and 0.010" brass shim stock, cut with scissors to slide between the side of the gib key and the crankshaft groove, and also the flywheel groove.  Once I tapped the gib keys in, the noise went away. 

Now, it's also possible some of the noise is from backlash in the idler to cam drive gear.  That one is more difficult to fix and involves machining an offset idler pin to allow you to adjust the mesh of the idler gear.  Once you get these engines dialed in, they run fine.  But the way they come from India, all bets are off.  Every engine is an individual.

Quinn

P.S. Here's the link to the thread from 2009 when I described what I did:

http://listerengine.com/smf/index.php?topic=962.msg12839#msg12839


« Last Edit: September 24, 2017, 06:25:26 AM by Quinnf »
Ashwamegh 6/1, PowerSolutions 6/1 "Kit" engine, and a Changfa R175a that looks like a Yanmar I once knew

Tom

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Re: New to listers, is a knock normal?
« Reply #22 on: September 25, 2017, 01:47:42 AM »
Great point Quinn. I would guess it is on the side with the cracked spoke.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 3k hours.