Glazed bores.

[Greg65]

Hi Guys and Gals,

With this frustrating period in England and being confined to barracks I decided to investigate the high oil consumption of my GS1000.

I brought the bike with pods fitted and could smell a very rich mixture. On investigation of the carbs I found the main jets 10 steps up from original after much testing settled on 3 steps up and put a couple of thousand miles on the old girl. It was a bit of a fill up with oil and check the petrol to start with but it did improve towards the end. There is no obvious smoke out of the exhaust however there is signs of carbon/oil staining around the end.

So I decided to do a top end overhaul as I suspected the valve stem seals. Opened her up, heavy coaking on the pistons, cylinder heads and valves. The valve stem seals were in good condition and looked to have been replaced prior to my purchase. However the cylinder barrels were shiny and looked a honey colour with visible honing still present. So I suspect I have glazed bores due poor running in made worse by a very rich fuel mixture in its previous life.

So in terms of correcting the problem once I get the bores measured and assuming they are within tolerance can I just hone/de-glaze them and use the original rings or will new rings be required. Advice on how to proceed and what to check would be appreciated.

All the best,
Greg

[Redman]

(subscribed)

[Rust_to_Redemption]

Hi Guys and Gals,

With this frustrating period in England and being confined to barracks I decided to investigate the high oil consumption of my GS1000.

I brought the bike with pods fitted and could smell a very rich mixture. On investigation of the carbs I found the main jets 10 steps up from original after much testing settled on 3 steps up and put a couple of thousand miles on the old girl. It was a bit of a fill up with oil and check the petrol to start with but it did improve towards the end. There is no obvious smoke out of the exhaust however there is signs of carbon/oil staining around the end.

So I decided to do a top end overhaul as I suspected the valve stem seals. Opened her up, heavy coaking on the pistons, cylinder heads and valves. The valve stem seals were in good condition and looked to have been replaced prior to my purchase. However the cylinder barrels were shiny and looked a honey colour with visible honing still present. So I suspect I have glazed bores due poor running in made worse by a very rich fuel mixture in its previous life.

So in terms of correcting the problem once I get the bores measured and assuming they are within tolerance can I just hone/de-glaze them and use the original rings or will new rings be required. Advice on how to proceed and what to check would be appreciated.

All the best,
Greg

If I was going through the trouble of pulling the head, I would just go ahead and replace the rings while I had it apart because they're not that expensive, and if it was running as poorly as you said for any length of time, I would want to pull off the old rings and make sure the seats aren't all full of carbon and inhibiting proper seating anyway. But also, are the cylinders shiny as you stated or can you still see consistent cross hatching? Shiny anywhere would be a rehone at the least for me. Do you have any symptoms other than oil consumption? Is the bike overheating? Loss of power?

[Greg65]

Hi Rust,

No just high oil consumption. It looks like the rings are only 3,000 miles old since a refresh by a PO as cam chain guides, pistons and valve stem seals all look fresh

[Rust_to_Redemption]

In that case, I would hone, check its all within spec, and then just send it with what you've got. If you dont already have a hone, I would recommend getting one of the ball hones of the appropriate size for your engine, those work much better in my experience than the "universal" hones.

[Tom R]

Check the ring to piston groove clearance too to make sure that’s not an issue. If they’re sloppy in there they won’t seat right. I’d assume if someone went through the trouble of honing it, they’d get new rings too. But who knows what POs might do.

[Tom R]

Just saw you said new pistons.... so they’re likely good.
I know someone who had to fix a base gasket leak and reused lightly used rings after a ball hone... worked ok for him, but he’s cheap, impatient, and far from a perfectionist... but most will recommend against it. You’ll likely not get any definitive info on that subject, so depends if you’re the experimental type or not.

[fastbysuzuki]

If I was going through the trouble of pulling the head, I would just go ahead and replace the rings while I had it apart because they're not that expensive,

extremely expensive in the uk for Oem rings although I spotted a Oem suzuki set standard bore for £100 on eBay this is £150 cheaper than a dealer.

[Rijko]

you may want to check the gap on the oil scrape rings.
I have seen several bikes with that gap too large, don't know
if those were OEM or not.
Replacing just those rings solved the oil issue.

[Greg65]

Great advice from all. Really appreciated and will follow up.

thanks,
Greg

[Big T]

extremely expensive in the uk for Oem rings although I spotted a Oem suzuki set standard bore for £100 on eBay this is £150 cheaper than a dealer.

To quote Nessism "To measure is to know"

Get everything measured before you make any decisions

You don't know how good/bad a job the last guy did on your motor

[Grimly]

If you need rings, Cruzinimage is good.
I used my OEM rings last year, but immediately replaced them in stock with a set of his, after a fair bit of research into the quality of his parts. He gets a really good name on the Honda forums, so thought I'd give it a go.

https://www.cruzinimage.net/2017/08/30/78-81-suzuki-gs1000-standard-piston-rings-set-4-rings/

[GregT]

Worth looking to see the rings are right way up too. If the mileage is as low as you think, the markings should still be visible - and on the top surface.

If you reuse those rings, run them in post deglaze on a mineral oil.

[oldGSfan]

I had my GPZ 1100 honed and it blew oil as bad or worse than before. Maybe the shop didn't really check for out of round. I was too trusting. Sure was a hassle to tear it all apart again with my hopes of a smokeless motor dashed. I bored it to 1166 with Wiseco pistons. Then it not only didn't burn oil but had a bit more oomph.

[Greg65]

Thanks again. The starting point as pointed out is to measure.

Cheers,
Greg