Question on Points Ignition - maxxed out?

[crazyramen]

Hey y'all I've never worked on a points ignition system before and tried to set the timing on my '79 750. I think the timing is maxxed out and I just wanna confirm.

Some quick background on the engine:
The bike had been sitting for at least 5 years before I got it. I saw it running very, very poorly when I bought it. It has bad compression in cylinders 1+4 (~30psi) that I've traced to valves that are waaay too tight - shims that were .15mm smaller than the ones currently installed still had less than .038mm of clearance (the size of my smallest feeler gauge.) I've taken apart the engine to hone the cylinders and lap the valves.

OK now on to the ignition:
When I opened the cover I saw that the main plate was turned almost fully clockwise (retarded?) - see the pic. The gap was way off as well. Does this mean the contacts are too worn? I was able to adjust the points for cylinders 2+3 to get the timing and gap correct, but since 1+4 are attached to the main plate I couldn't get them set up right.

Does this mean that the contacts are too worn?

I assume this is what caused the problems on 1+4 leading to tightened up clearance, since this is the only real difference I could find between the cylinders. Does that make sense?

 

[oldGSfan]

I think I'd pull the valve cover off to see if the chain/cams are in the correct orientation. Start from the fundamental principles.

 

[crazyramen]

Valve timing is good. I set it when I did the cylinder and valve lapping. Wouldn't that effect all cylinders anyway?

 

[oldGSfan]

Valve timing is good. I set it when I did the cylinder and valve lapping. Wouldn't that effect all cylinders anyway?

OK well yeah, good point. All my GSs have had EE, whether stock or Dyna. I had an '82 1100E with a twisted crank, that really caused me grief, but thinking about it, would it affect 1&4, 2&3? I don't think so.

So if you have the compression issue resolved, and know the valve timing is good, it does leave the points assembly as suspect, as far as I can tell. There will be better analysis than mine from the usual suspects here.

I like setting up points better because you can set static timing accurately with a bulb or meter. Working on a Norton with a Boyer recently, it was set by a hole in the plate with a sloppily painted dot behind it on the housing. And pray, fight kickback till it would run by retarding ignition bit by bit, then get out the strobe. My knee is still sore.

 

[rphillips]

Gosh, it's been a long time since I fooled with GS points... Maybe should just keep quiet, but remembering for me it was much easier if you do one set first, but can't remember which set should be first. If do the wrong one first the other is a pain, but I don't remember how or why.

 

[crazyramen]

OK well yeah, good point. All my GSs have had EE, whether stock or Dyna. I had an '82 1100E with a twisted crank, that really caused me grief, but thinking about it, would it affect 1&4, 2&3? I don't think so.

So if you have the compression issue resolved, and know the valve timing is good, it does leave the points assembly as suspect, as far as I can tell. There will be better analysis than mine from the usual suspects here.

I like setting up points better because you can set static timing accurately with a bulb or meter. Working on a Norton with a Boyer recently, it was set by a hole in the plate with a sloppily painted dot behind it on the housing. And pray, fight kickback till it would run by retarding ignition bit by bit, then get out the strobe. My knee is still sore.

Jeez a twisted crank sounds like it could drive someone insane checking valve timing...

Waiting on some more shims to be shipped to confirm, but it seems like .15mm+ of valve opening would sure cause some loss of compression.

I saw some knock off Dyna Ss on ebay for ~$30 - might be worth it.

Gosh, it's been a long time since I fooled with GS points... Maybe should just keep quiet, but remembering for me it was much easier if you do one set first, but can't remember which set should be first. If do the wrong one first the other is a pain, but I don't remember how or why.

The Suzuki and Clymer manuals both recommend to set the 1+4 (left point) first since it's directly attached to that main plate, and 2+3 (right point) next since it's on a secondary adjusting plate. I could see how doing it backwards would also cause some insanity.
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[crazyramen]

I have a knock off Dyna on my 750 (others on here said they have had luck with them) and so far so good after a few hundred miles. I bought NOS Suzuki points and condensers for my 750 and it initially ran well but then deteriorated. I suspect a condenser went bad but I didn't bother checking them as I had the Dyna waiting in the wings anyway.

Yeah it'll be the same price for the knock off as new points+condensers so I'm thinking I'll skip the headache of messing with points.

 

[crazyramen]

Posting for future folks who are looking for the same info:

I moved my discussion to here

https://www.thegsresources.com/_for...9918-1978-gs550-timing-plate-max-out-rotation

Confirmed to be worn down contacts by a person on youtube setting timing on their 550