Mike’s rattling GT550B

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yeadon_m
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Joined: Sat Jan 02, 2010 7:10 am
Location: Canterbury Kent

Mike’s rattling GT550B

Post by yeadon_m »

On my way back from Dudley. Huge thanks to Baz & Carmen for making me so welcome at their family friendly home.
Cracking workshop! I’ve been plagued by this rotten 550B for much of my ownership. Some time ago, Alan visited with a spare top end (like you do) & it seemed great after that. But quickly it developed a severe rattle on the left, as soon as it was fully hot.
Life’s been too busy, what with becoming a granddad for the first time that I’d simply thrown a blanket over it. A couple of days ago, I trailered it up to Barry’s & we did some studies. We found that the rattle was top end and was immediately extinguished if a little light oil was sprayed into the left carb when it was running. Stripped that cylinder. All the bored look v good. Changed the little end bearing & oil pump (“just in case”). Today, 5 miles round his estate & ajoining main roads, doesn’t seem to rattle!
I’m on my way home, here’s me on the M40 services.
Hope everyone has kept safe through the viral panicdemic!
Cheers, Mike
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slosher
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Joined: Fri Sep 23, 2011 6:55 pm
Location: Walsall,Black Country

Re: Mike’s rattling GT550B

Post by slosher »

Hi Mike
Good to hear you are all well and bought the 550 out the naughty corner :lol: Let's be honest it could be worse you could have a Kwak :lol: :lol:
I think all air cooled Suzuki's have a certain noise slight rattle,ring scrape etc,mine has a bit of piston slap that does my head in sometimes but i live with it,all i do is take the Bonnie out for a spin and realise what a nice quite motor the 550 is :lol: :lol: :lol:

Stay safe
Cheers Dave
GT750L
GT550L
TL1000 97s
T140V
Loctite Trained Engineer :lol:(since having the Bonnie)
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canaletto5
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Location: Derbyshire

Re: Mike’s rattling GT550B

Post by canaletto5 »

Good to see you are out and about Mike. PS: You didn't happen to pick up Dominic Cummings by any chance?
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Alan H
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Location: Wombwell, Republic of South Yorkshire

Re: Mike’s rattling GT550B

Post by Alan H »

Good news Mike. Now get some miles on and see if you start to like it!
Proof that four strokes are over complicated
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yeadon_m
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Joined: Sat Jan 02, 2010 7:10 am
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Re: Mike’s rattling GT550B

Post by yeadon_m »

That Cummings tried to thumb a lift just south of Dudley. No chance, I told hm. The whole bikes scarcely 2metres long.

Took the bike out in its natural habitat this afternoon, sweeping rural A roads & associated connecting roads, many of these are tarmac’d field boundaries.

This was the first ride, in what I think of as the Middle Period of my ownership, where I felt really pleased with it. Cold or hot, so far (& I’m up to 30 miles since yet again that left cylinder got some attention) it’s remained sounding like a new GT triple should. I won’t pretend it’s not a surprise. Barry & I speculate that perhaps this is an “anti-blueprint” of a motor, where several of the allowed tolerances at their extremes & it then just doesn’t all sit as well together as expected. All we’ve done is to replace the small end bearing, polished off the slightest scuff on the piston skirt on the intake side & swapped the pump (on a just in case basis). We did verify we could see oil being emitted from the spider oil line banjos & that the oil-ways are clear.

My word though, even though it’s still running in time, this bike feels swift! Sounds brilliant, rides super smooth, feels planted yet nimble etc. Oh, and though I’ve always been careful to check oil delivery, I confess to the oiling in the tailpipes after today’s short ride is as even as you could ever hope to get.

Maybe, just maybe...

Hope you’re all keeping well,
Mike
crazy4557
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Joined: Sat Dec 07, 2013 1:24 pm
Location: Lymington, Hampshire

Re: Mike’s rattling GT550B

Post by crazy4557 »

Glad to hear your 550 is not having a hissy fit again Mike.

I've got a similar issue but I think oil delivery, what is the process for checking oil delivery to the cylinders via the spider? My new engine runs OK, sounds good but the offside outer cylinder runs hot like 158 degrees against 120 or less for the other two and v little smoke from the tailpipe. The other two cylinders are pumping smoke nicely. These temps are from a bike that's been runs for 2-3 minutes only.

Sorry to barge in on your parade :o
1976 GT550A in black
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yeadon_m
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Re: Mike’s rattling GT550B

Post by yeadon_m »

No problem! There are lots of ways to test oil delivery. Methodically, I lift the oil pump, leaving it attached to the oil tank. Holding it so I can see the base & six holes, wipe it clean of oil. Leave the lever at idle, use a thin electrical screwdriver to steadily rotate the pump shaft (don’t lose the pin, or forget to replace it when you put the pump back on it’s baseplate!).
You should see oil emitting slowly from three holes only. These are crank feeds. Open the pump lever halfway. Keep turning the pump shaft. Now you will see the other three holes squirting oil out! These are the cylinder feeds.
If this tests out OK, use an oil can with a nozzle to squirt oil through each of the six holes with O-rings in the baseplate. You can feel if the opening pressures of the six banjos feel the same. They should. If you’ve any doubt, remove the spider for separate testing.
If all’s well, refit the pump.
If you want to see it working while assembled, take out plugs, airbox, carbs & intake rubbers.
Peer into the cylinder intakes. You can see a brass oil feed tube in each. Shine a torch on the opening of a tube. Chock the oil pump lever with a socket like 22mm. Hit the starter button. It may take quite a while to pump, and note it’s only briefly during each full turn of the pump shaft, but it’s unmistakable once you’ve seen it happen. Check it looks same in each intake tube.
Checking the crank is much harder. The oil output is so minuscule & not much increased with the pump lever position. You can detach it from the crankcase, clean it carefully, then place clean blue tissue under the banjo. Be ready to turn the motor over for up to a minute in 4x 15sec bursts. If it’s pumping oil, you’ll be able to see it on the blue shop towel.
Hope of some help!
Cheers,
Mike
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canaletto5
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Joined: Tue Jul 23, 2013 8:43 pm
Location: Derbyshire

Re: Mike’s rattling GT550B

Post by canaletto5 »

crazy4557 wrote:Glad to hear your 550 is not having a hissy fit again Mike.

I've got a similar issue but I think oil delivery, what is the process for checking oil delivery to the cylinders via the spider? My new engine runs OK, sounds good but the offside outer cylinder runs hot like 158 degrees against 120 or less for the other two and v little smoke from the tailpipe. The other two cylinders are pumping smoke nicely. These temps are from a bike that's been runs for 2-3 minutes only.

Sorry to barge in on your parade :o
It looks like that pot might be running lean? Just check the plug to see if it is normal lightish brown. if it is white then the carb may need adjusting. Kev
crazy4557
Posts: 550
Joined: Sat Dec 07, 2013 1:24 pm
Location: Lymington, Hampshire

Re: Mike’s rattling GT550B

Post by crazy4557 »

yeadon_m wrote:No problem! There are lots of ways to test oil delivery. Methodically, I lift the oil pump, leaving it attached to the oil tank. Holding it so I can see the base & six holes, wipe it clean of oil. Leave the lever at idle, use a thin electrical screwdriver to steadily rotate the pump shaft (don’t lose the pin, or forget to replace it when you put the pump back on it’s baseplate!).
You should see oil emitting slowly from three holes only. These are crank feeds. Open the pump lever halfway. Keep turning the pump shaft. Now you will see the other three holes squirting oil out! These are the cylinder feeds.
If this tests out OK, use an oil can with a nozzle to squirt oil through each of the six holes with O-rings in the baseplate. You can feel if the opening pressures of the six banjos feel the same. They should. If you’ve any doubt, remove the spider for separate testing.
If all’s well, refit the pump.
If you want to see it working while assembled, take out plugs, airbox, carbs & intake rubbers.
Peer into the cylinder intakes. You can see a brass oil feed tube in each. Shine a torch on the opening of a tube. Chock the oil pump lever with a socket like 22mm. Hit the starter button. It may take quite a while to pump, and note it’s only briefly during each full turn of the pump shaft, but it’s unmistakable once you’ve seen it happen. Check it looks same in each intake tube.
Checking the crank is much harder. The oil output is so minuscule & not much increased with the pump lever position. You can detach it from the crankcase, clean it carefully, then place clean blue tissue under the banjo. Be ready to turn the motor over for up to a minute in 4x 15sec bursts. If it’s pumping oil, you’ll be able to see it on the blue shop towel.
Hope of some help!
Cheers,
Mike
Thanks both of you!

Mike...I'll take a look at the weekend, will be very interested to see whats happening and I'll report back.
1976 GT550A in black
crazy4557
Posts: 550
Joined: Sat Dec 07, 2013 1:24 pm
Location: Lymington, Hampshire

Re: Mike’s rattling GT550B

Post by crazy4557 »

canaletto5 wrote:
crazy4557 wrote:Glad to hear your 550 is not having a hissy fit again Mike.

I've got a similar issue but I think oil delivery, what is the process for checking oil delivery to the cylinders via the spider? My new engine runs OK, sounds good but the offside outer cylinder runs hot like 158 degrees against 120 or less for the other two and v little smoke from the tailpipe. The other two cylinders are pumping smoke nicely. These temps are from a bike that's been runs for 2-3 minutes only.

Sorry to barge in on your parade :o
It looks like that pot might be running lean? Just check the plug to see if it is normal lightish brown. if it is white then the carb may need adjusting. Kev
Thanks Kev, carbs rebuilt by Baz so assuming/hoping they are correctly setup but I'll pull a plug and see.
1976 GT550A in black
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