1978 GS550ET top end inspect/rebuild

[Nicholk]

Vapour blasting

Vapour blasting

OK, back to the grindstone again after a longer than expected break.
Have now received the bits back from vapour blasting and they're looking so much better now. See pics:

And these are the before and after shots of the head and barrels:

My worry now is that the head may still need skimming:

This is a closeup of the worst part of the head

Has anyone fitted a head like this before..?? Will the gasket seal sufficiently if I use jointing compound as well..??
All advice appreciated

 

[Nicholk]

Head skim

Head skim

Mmmmm.......more research seems to suggest use of jointing compound is a really big mistake. Looking closer it's a skim reqd and possibly block refaced as well. Off to the shop it is next week. I'll also get the bores mic'd up and either honed or rebored depending on results. Time to get the wallet emptied again...!!

 

[Nessism]

The critical sealing areas are a band around each cylinder and around the cam chain opening. Pitting in the areas away from combustion pressure are no worry unless they are really deep. I suspect your head will be fine as long as you use OEM Suzuki gaskets. No NOT use Athena or other cheap aftermarket gaskets.

 

[Nicholk]

Skim

Skim

Thanks for that........sadly there is some pitting around the cam chain opening and at the side of 2 of the combustion chambers....the photos don't show it up too well. I took it to the local shop this morning and they were in agreement so a light skim is being done...same for the barrels. Here's hoping the skim does not produce new problems..!!

 

[Nessism]

Skimming should pose no issues. The GS engines have really thick deck surfaces. Only problem is the cost and finding a reputable shop you trust to do the work.

 

[Nicholk]

Gaskets

Gaskets

OK, still waiting for the bits to come back from the shop. Meanwhile I've been looking at obtaining the gaskets. As several posts have advised the use of OEM for the base and head gaskets, I've found that these are still available here in the UK as well.......cost ?65 for the 2. That's just over $100 so comparable with most of the posts I think. My question now though is should I also go OEM for the other gaskets and O rings..? I can get a pattern full set for ?60 and just not use the head/base gaskets from this....are these OK in peoples opinion..? Otherwise it's order individually as the OEM set is no longer available

 

[Nicholk]

Skim done

Skim done

Head and barrels back and looking good. Next week will see the valves lapped before final clean and air blast before reassembly. Cylinder i.d checked and still well in spec so no new pistons or rebore reqd. Will be taking barrels for glaze bust then final clean and air blast as well before fitting new rings.

 

[Nessism]

You might want to check the US ebay site for gaskets. These guys can save you some money...http://www.ebay.com/itm/SUZUKI-GS55...essories&hash=item58a0413cdd&vxp=mtr#shpCntId

Using a pattern set for the non critical gaskets shouldn't be a major concern. In my experience, the OEM gaskets that are critical are the base, head and valve cover. The valve cover isn't critical per say, but the OEM gasket will typically last longer since it's more tear resistant as you go forward doing valve adjustments with the bike in service.

 

[Paul]

A great thread, lots of stuff covered that the book doesn't... cheers good luck with it!

 

[Nicholk]

O rings

O rings

Thanks for that, looked at the gasket from USA and it is not quite the p/no I was looking at....I would think it's a backward sub? My main worry would be transit damage with a gasket. Suspect I'll stick with the new one I've priced already....I'll be doing a bulk order so can (should be able to) guarantee good
packing in a box.

My question now though to all who have done a rebuild before....
The 4 O rings that go at the bottom of the barrels..... 09280-61001....for the life of me I have been unable to find any sign of these having been fitted..!!
They weren't in the recesses and were not stuck to the base.....has anyone seen this before or is there any chance they would drop down into the crankcase..? I can't see any sign of them and am somewhat concerned.

Thanks

Keith

 

[Nessism]

Those O-rings pinch into a groove around the liners. Bet they are there, but tucked in tight. Maybe try a pin to see if you can find anything soft tucked into that groove. If they are in there just leave them be.

 

[Nicholk]

O rings

O rings

Nope, def not there:

Talked it over with my mate who assisted and we are both confident that nothing fell off. We suspect that these came off/out during the vapour blasting and they just forgot to mention it. Sadly I never thought to phgotograph the u/side of the barrels so have no record to check....will not make that mistake from now on............rather too many photos than miss something else..!

Taking barrels for honing tomorrow....2-3 day turnround so poss by the weekend.

 

[Nicholk]

Valve lapping advicereqd

Valve lapping advicereqd

OK, back to the bike work after a long time away. Skimming done, cylinder honing done, now progressing to valves.
The problem I have is pitting of the valve seats. Started to lap but very quickly ran into problems with my hands/fingers....rheumatoid arthritis really sucks at times..!!
Fortunately I have a good friend who loves this sort of thing and he volunteered to do this for me. It's taking more work than we thought to get rid of the pits and there is now a minute lip beginning to form on the valve itself. I'm going to try a get photos but would like to know if anyone has come across this? Am I looking at recutting seats.? If I am can I still use the valves.?

 

[Nicholk]

Valve lap advice reqd

Valve lap advice reqd

Here are the photos of the worst example. There a 3 a little better and 4 that are OK.

 

[Nicholk]

Well, back to the rebuild after yet another enforced break......ongoing illness relapse. Sometimes life does like to remind you it's not all roses...!!
Still, back on my feet and starting the build again.
Hit the first issue with the rings....for which I opened a separate post.....sorted now.
Had a thought then that there must be plenty of people on this forum that have done this work already.
Thought I'd ask the question:

Any particular foibles involved in the top end rebuild.?

Seen a few issues in previous posts but mostly looks straightforward.
I hope so 'coz it's been a while since I stripped it down..!

Lining up a couple of friends to assist with fitting barrels so will be a week or so before this happens.
Meantime the rest of the bike is getting looked at.......



My dining room table at the mo'....
Still loads of elbow grease reqd.

All tips gratefully received....

 

[Nicholk]

Interesting to read the various posts on the use of sealants on gaskets etc. I think the only one I will follow is perhaps a smear of grease on the rocker cover.

 

[Guest]

Great posts and great pictures. All of us here on GSR appreciate your efforts. Keep up the good work!

 

[ShadowFocus603]

I do the grease on the rocker cover as well simply because that's usually the only part that gets removed with regularity (valve adjustments) and I like being able to re-use the gasket rather than shredding it each time.

 

[Nicholk]

Ok, long gap between posts. The Gods of restoration did not smile for a long time.
Had to cope with lots of issues including the build of a self contained annexe for my Father.
This was followed by an "off" on my Triumph........once again gravel takes another victim.
Fortunately was wearing all the gear but was using single skin leather summer gloves.
Slide protection was fine but the initial impact hurt.
Result was broken knuckles and a couple of days in hospital.
permanently ride with the Alpinestars from now on regardless of temperature.

Still, after 2 years the rebuild is back on.
Rings installed.
Pistons fitted,
Gasket surfaces final cleaning done.
All valve seals and valves fitted after lapping.
New studs installed into block.

Then had to wait for both my biking friends to come free at the same time to assist.
OEM base gasket fitted as per most peoples recommendation.
Barrels installed with all 3 of us working to ensure the rings went in smoothly....my ring compressor fell
foul of the garage poltergeist and was nowhere to be found!
Cylinder head on with brand spankers nuts, cams installed and everything torqued down.
Once again however the garage poltergeist intervened.....that and my failure to check and recheck the manual.
I had failed to install the camshaft guide due to the above mentioned pg hiding it.


Luckily it was fairly easy/flexible enough to install with the chain in place.

Checked the cam clearances and ordered the new shims reqd.
Used the tie wrap trick from this site......works perfectly.....once I got the hang of it.
Now it's just waiting for the shims to arrive.
In the meantime I've got lots of work to do cleaning/checking the rest of the bike before
calling on my friends again to refit the engine.....and complete the rebuild.

Cost me several beers and a bbq for the previous assist....probably the same again for the next time.
Well worth it..!

Hopefully won't be 2 years before next post..!!!

 

[Nicholk]

Engine as is from rear.