How I un-seized my GT550 engine!

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Gr8uncleal
Posts: 126
Joined: Mon Jan 15, 2018 7:17 pm

How I un-seized my GT550 engine!

Post by Gr8uncleal »

Not being the most patient chap, having made a token attempt at using various penetrating fluids, not having access to any heat source, but also not wanting to resort to brute force and ignorance, I was struggling to find a way to un-seize my Canadian import Suzuki GT550 (the importer stated seized due to standing, but more of that later!).

What I do have, however, is a nice large engine hoist with lifting straps and it occurred to me that if I could somehow attach the straps to the barrels, one at a time, then maybe I could lift them and use the weight of the bike to break the seizure.

As the cylinder head mounting studs on the barrels don’t go all the way into the crankcases, I thought that it might be possible to use these as a holding point for the straps.

I bought two mild steel bars off ebay (100mm x 25mm x 10mm) and drilled two 11mm holes in each, so that they could sit on the studs. A couple of washers and M10 nuts on each stud and the strap could sit nicely under them. Attach the two ends of the strap to the engine hoist and off we go!

Well, to quote Ben Elton, bugger me backwards with a blunt root vegetable, it worked!!

The right cylinder broke free straight away, the left one (which I already knew had “issues”!) broke off at the small end bearing(!) and the centre one needed a tap with a wooden mallet and length of wooden dowel to free it.

A series of photos are attached for the amusement of you all. These show my apparatus in action, as well as what is left of the left side piston, both in and out of the barrel! There was me hoping that nothing would have dropped into the crank!!

I do have another complete bottom end, barrels and pistons that I can use to get the bike on the road fairly quickly, although part of me would still like to keep the original crankcases and therefore engine number.

Still, I’m well chuffed that my rather wacky idea worked.

I’ve posted this on a couple of other forums that I’m on, so apologies if you end up seeing it more than once.
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barney01
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Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

Re: How I un-seized my GT550 engine!

Post by barney01 »

What a result ! If that had been a 750 it may have not worked though. They seem to really get stuck :shock:
Problem is I think there will be debris down in the crankcase. I think it's a good idea to try to find out why the engine seized if you can :?:
Still that method of extracting the cylinders is perfect and those hoists are not too dear to hire if you don't own one.
NO SMOKE .......NO POKE
Gr8uncleal
Posts: 126
Joined: Mon Jan 15, 2018 7:17 pm

Re: How I un-seized my GT550 engine!

Post by Gr8uncleal »

Thanks Barney.

As soon as bits of piston and rings came out of the exhaust when I took it off I knew that I was in trouble! When I couldn't feel any piston when I put my finger into the barrel via the exhaust outlet I knew I was in big trouble!

All I wanted to do was un-seize it so that all options are open to me as and when it is stripped down. As I say, I already have another engine that I can drop into the bike.
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Alan H
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Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: How I un-seized my GT550 engine!

Post by Alan H »

Have a quick look at my GT550 resto threads and you'll see how I make the crank seals happy without a strip and rebuild.
Proof that four strokes are over complicated
Gr8uncleal
Posts: 126
Joined: Mon Jan 15, 2018 7:17 pm

Re: How I un-seized my GT550 engine!

Post by Gr8uncleal »

Will do, thanks Alan.

I don't suppose that Dyson have come up with a nano-cleaner that can go all around the crank, collecting swarf and other detritus yet, with the engine in situ, have they.............?!
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Alan H
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Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: How I un-seized my GT550 engine!

Post by Alan H »

Yes, of course.
A very wise purchase for only £3,467,899.99 (+ vat). :roll:
It may also clean out other orifices if required. :shock:
Proof that four strokes are over complicated
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Alan H
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Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: How I un-seized my GT550 engine!

Post by Alan H »

The 3 550s I have restored had been stood a long time, so I took the head and barrels off them and filled each crankcase with diesel and turned the engines over slowly - each day for a week or more - drain the diesel out and repeat - (via SRIS valves in the front of the cases.)
This should wash all the bearings and soften the crank seals. It's worked on both my engines on the fully restored bikes, and the J engine is currently soaking!
It might be worth trying on yours before you actually go out riding it. Oil the bearings before starting it again - lots of smoke but the engines seem to benefit from it. 
You might need 'easy start' to get it going! I used it before I fitted the airboxes and squirt directly into the carbs, a bit at a time until the smoke cleared and the engine runs without spluttering.
Unfortunately, if the seals are knackered, then it's game over, but always worth a try for the sake of a couple of quids worth of tractor blood.
Last edited by Alan H on Tue Jul 16, 2019 10:29 am, edited 1 time in total.
Proof that four strokes are over complicated
Gr8uncleal
Posts: 126
Joined: Mon Jan 15, 2018 7:17 pm

Re: How I un-seized my GT550 engine!

Post by Gr8uncleal »

Thanks Alan H.

I suspect that, at a very pedestrian rate given that I've got 3 other restos on the go, I'll swap over engines and get the one currently on the bike stripped and cleaned. If things don't look too bad (ie crank and con rod ok), then I can mix and match the cleaned up original bottom end in the original crankcases with the replacement set of barrels and pistons that I have already purchased.

For the moment I'm just pleased to have got it un-seized!

Alan B
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