Author Topic: SR2 bad vibrations  (Read 162 times)

Help I have a Lister

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SR2 bad vibrations
« on: August 03, 2018, 07:26:05 AM »
My SR2 is solid mounted on a boat. It vibrates like hell is there anything that can be done.
Regards.

dieselspanner

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Re: SR2 bad vibrations
« Reply #1 on: August 03, 2018, 08:42:51 AM »
Yes, but it ain't cheap.......

Pull the engine and gearbox, alter the engine beds and re fit with flexible mounts and a flexible coupling to the propeller shaft.

You might well have to slip the barge and have the prop shaft machined to suit, so fit a ceramic shaft seal (assuming you don't already have one) at the same time.

If you're not desperately in love with the Lister and have the budget then there are quieter modern engines.

See your local boatyard for details, some times second hand engines pop up.

Cheers Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

glort

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Re: SR2 bad vibrations
« Reply #2 on: August 03, 2018, 10:20:13 AM »

I take it you have checked that it IS the engine and not loose/ broken mounts, worn thrust bearings, bent prop shaft, chipped/ out of balance prop?

Help I have a Lister

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Re: SR2 bad vibrations
« Reply #3 on: August 06, 2018, 09:27:35 AM »
Thanks for your replies. The vibrations seem engine related as it is evident when revving in neutral. Engine mounts seem fine. Iíve looked at flexible mounts but it is a heavy engine and there is not much clearance to the mounting beams to fit anything substantial. If thereís nothing I can do with the engine then might just have to start saving up.

glort

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Re: SR2 bad vibrations
« Reply #4 on: August 06, 2018, 11:49:50 AM »

You are not giving much info for anyone to help you here.
Is it a vibration like a high frequency rattle or more like a Knocking/ slower effect?
I'm wondering if you could have a lazy cylinder thats not pulling it's weight due to low compression or blocked injector or conversely, an injector that is partially help open and firing harder than it should.

If you want meaningful suggestions, more info would be useful.

cobbadog

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Re: SR2 bad vibrations
« Reply #5 on: August 07, 2018, 01:32:05 AM »
I would start by doing a full service on the engine and a compression check to establish where the problem lies. Hopefully it is just as suggested a fuel system issue and not rings and bearings. Either way it is a time thing more than anything else.
Good luck with the trouble shooting.
Coopernook - the centre of our Universe.

Hugh Conway

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Re: SR2 bad vibrations
« Reply #6 on: August 08, 2018, 10:26:01 PM »
Once upon a time I had a sailboat with an SR2. The engine was lag bolted to wooden bearers, had the then usual non-flexible coupling that required a lot of shimming to align gearbox output and prop shaft. Had the old style stuffing box.
When running, inside the boat, it sounded like a destroyer running at war emergency power, but the vibration was not excessive.
I would look for some of the suggested causes, but would bet it is not the basic engine design. There things were a common life boat engine, and were reliable and trouble free.
Cheers,
Hugh
JKson 6/1  (Utterpower PMG ) Off-grid
Lister 6/1 Start-O-Matic engine......running with PMG
1978 Royal Enfield (glutton for punishment by Indian iron)
1963 BMW R-27 project

Help I have a Lister

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Re: SR2 bad vibrations
« Reply #7 on: August 11, 2018, 02:06:43 PM »
Thanks for your replies folks. Sorry for the delay in getting back. When I got the boat the engine was a poor starter and guffed like hell. I had the bores polished, new rings, a new valve, injectors checked, new crank shims and now it starts second turn, idles nicely  and is much cleaner. Iíll get a compression check and let you know. Cheers.

cobbadog

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Re: SR2 bad vibrations
« Reply #8 on: August 12, 2018, 04:32:39 AM »
Sometimes 'terminology' can get lost when making a description on things done. "Polishing' the bore would be something I would avoid but having it lightly honed would be better especially when fitting new rings. the rings need something to 'bite' into so that they can seal and give good compression. doing a compression test on a new engine may not achieve much as the rings have not been bedded in and once they do you should have no issues there. With all that work done you need to look at other sources of the problem. Have a very close look at what the engine is mounted to. Is it solid and strong and not rotting away?

I just re read your last post and you say that with the upgrades to the engine it now starts on the 2nd turn and idles nicely and is much cleaner. SO does this mean the problem has gone?
Coopernook - the centre of our Universe.