1978 gs550 Timing plate max out rotation

[tmore5585]

Greetings. I am completely baffled on this one and there does not seem to be any info in my Clymer service manual or anywhere else regarding my 1978 Suzuki GS 550E timing issue. I have set up my cam shafts and cam chain to there correct marking arrows along with new contact points and valve clearances within spec.My alignment looks perfect and the engine turns smoothly but when attempting to set the timing using a electrical test bulb the # 1 & 4 "F (fire)marker on the GOVERNOR ASSY seems to be out of alignment because the test light bulb comes on way BF it is supposed to and the rotatable contact plate to adjust timing is maxed out all the the way clockwise leaving no more room to rotate it to properly adjustment the timing. Counterclockwise rotation gets the timing even farther off. Is it possible the cam chain has stretched too much? I would assume the cam chain tensioner would eliminate that from being a problem and seems to be working smoothly. Maybe the governor assembly lobe ware the contact points arms brush against has worn down over decades? Has anybody seen or experienced this sort of thing. Any help would be greatly appreciated

[oldGSfan]

There's another recent post that seems similar. Not having such a bike in front of me I can only guess but the symptoms sound similar. I wonder if the advance mechanism is working correctly. That's all I can think of. Maybe you can check it out and compare notes..

https://www.thegsresources.com/_forum/forum/technical-forums/electrical-ignition/1769918-1978-gs550-timing-plate-max-out-rotation

[tmore5585]

Thank you for your response Tom. I did see the post you are referring to unfortunately there is no real resolution regarding timing issues. I have already suspected my GOVERNOR advance assembly among other things. I did disassemble and lube it. Oddly enough the most in-depth references to it that I can find is Google automated or AI answering. It said a common problem is the removable lobe gets wore down over millions of revolutions by the breaker point arms rubbing against it for decades. How this could be referred to as a common problem is interesting considering there is barely even a mention of the subject anywhere including my service manual. I am now looking for some sort of spec so that I can possibly measure the lobe kind of like a cam lobe to try and determine if it needs to be replaced. There are new old stock governors for 4 sale on Ebay for just under $100. That is kind of pricey if that is not really my issue. Thanks for your help.

[Grimly]

Borrow a dial gauge.

[Rijko]

... when attempting to set the timing using a electrical test bulb ...

That sounds like static timing (vs strobe timing with running engine).
If so, the advance assembly is not the issue.

Did you check the cam timing ? Sure the chain has not jumped a tooth ?

You said new contact points - still have the old ones, and do they have the same issue ?
If these are not the right ones, the difference may be minimal but can cause timing issues.
Recently had exactly that issue on a GT250, could not get timing for 1 set of points right.

[crazyramen]

Having the same problem with my '79 750 with a picture here - this is what you're encountering too, right? Totally at a loss as well.

That sounds like static timing (vs strobe timing with running engine).
If so, the advance assembly is not the issue.

Did you check the cam timing ? Sure the chain has not jumped a tooth ?

You said new contact points - still have the old ones, and do they have the same issue ?
If these are not the right ones, the difference may be minimal but can cause timing issues.
Recently had exactly that issue on a GT250, could not get timing for 1 set of points right.

I have had the head off to hone the cylinder and lap the valves so valve timing is confirmed to be correct, but don't the points run directly on the crankshaft? I don't think the valve timing would change any thing having to do with setting static ignition timing but please correct me if I'm wrong.

[Rijko]

... don't the points run directly on the crankshaft? I don't think the valve timing would change any thing having to do with setting static ignition timing ...

correct ! I was not clear as to why i said that : tmore5585 said he turned the crank both ways to set timing. And that may cause the chain to jump a tooth... especially with a loose/stuck/removed tensioner.

[crazyramen]

correct ! I was not clear as to why i said that : tmore5585 said he turned the crank both ways to set timing. And that may cause the chain to jump a tooth... especially with a loose/stuck/removed tensioner.

Ahh yes totally. I learned that firsthand when I did the valve job

[tmore5585]

Grimly: I assume when you suggest to us a dial gauge that would be to check that Top Dead Center is correct after my cam & chain install. Couldn't I use a piston stop to find TDC? I have never used either but did check it out on YouTube videos.

Rijko. To set timing I have used both electrical test light with bulb that would be static timing and a timing light or strobe timing with the same results of not being able to rotate my breaker timing plate clockwise far enough to reach the "F" firing marker on pistons 1&4. My understanding is my governor assembly may have a problem even with static timing if its lobe has become worn or miss shaped because the feeler arms (that is what I am calling them) on the contact breakers will not push off of it correctly to open the other end ware the actual electrical breaker point is even with correct gap (0.3–0.4mm) You would think the governor assy lobe made of steel would not get worn down from the softer plastic feeler arms on the breaker points smacking off of it but possibly over 47 years it has. Seemingly this would be the same effect of having aftermarket breaker points whose feeler arms are not exactly formed to OEM standards and there off kilter shape is causing some sort of timing issue. Thanks for that suggestion. I had the same timing problem with my previous breaker points that were several years old but had very low miles on them. Both are aftermarket Ebay specials. There have not been OEM breaker point available in many years according to my local Suzuki dealer. It very will could be that both point sets are mis shaped causing my problem. Not sure how to make the determination.

Crazyraman I think you are right. Valve timing is set when you install exhaust and intake cams and chain. The high point on the cam lobes pushes down on the valve shim and bucket at the correct time only if cams and chain are set correctly. Ignition timing determines when the spark plugs fires. No the point breaker feeler arms (again my name for them) do not get pushed directly from the crankshaft. Or as you call it " points run directly on the crankshaft" the breaker points run or move off a Advance Governor Assembly cluster that attached to the end of the crankshaft. Go to Partzilla.com part # 11.The round lobe part that protrudes from the center of the cluster is what your breaker point feeler arms push off of to open and close the points. It is not completely round but has a bump or lobe that when rotating pushes your points open at its high point. Kind of like a cam lobe except much smaller of a bump. On the advance cluster there are also 2 arms attached by a post on other side secured by a C clip and small spring on the other end. The faster the advance cluster spins from the RPM of the engine the more centrifugal force pushes out the arms. This advances the timing or spark plug firing which is needed for higher RPMS. The springs pull back the arms at lower RPMs. That is why the cluster is called a Advance Governor Assembly. The parts of the advance assembly can be disassembled including the lobe by removing the C clips . What I have been discussing with Rijko is that possibly the lobe part has been deformed from the breaker point feeler arms rubbing against it for decades.


My cams and chain again are/were aligned perfectly. This included cam chain pin and pin count, all markers on cams and "T" 1 & 4 piston ignition marker, no hiccups, kinks or chain bobbles during many clockwise rotations. I busted my a$$ for several hours to get it sorted. The other day I took everything apart and purposely misaligned my cams and chain by 2 chain links counterclockwise to see if that would allow my contact plate to rotate enough for the "T" 1 & 4 piston marker to align. It did work. Now I CAN set ignition timing correct, with the contact plate fully rotated clockwise. The bike starts and idles even with no choke when warmed up but sounds completely different and bogs down upon throttle. My carbs are synced but need air/fuel mixture dialed in further. I have decided not to tinker with carbs yet and reset my cams\chain correctly then screw around with.

#1 Possible aftermarket misshaped points. #2 Advance Governor Assembly and or its Lobe. #3 Get or make a piston stop to make sure TDC is close to wear my bikes timing marker indicates it should be.

A possible solution that I thought of a while ago even B4 buying my latest aftermarket breaker points and purposely resetting my cams and chain incorrectly is to just elongate the 3 slots wear the contact plate mounting screws go through to allow for further rotation. That would seem to solve all issues if I could hack away far enough before getting to the end the plate. Possibly my 2 & 3 piston ignition timing might be affected.

Also would buying a cheap Ebay electronic ignition cure my lack of ability to rotate the contact plate? I am not sure how they work and initially wanted to figure out my timing issue B4 attempting it. Did not want to compound 1 problem on top of another. They have gotten almost as affordable as buying a breaker point set.

If anybody has the patients to have read this far any ideas as to were to go from here would be appreciated.

[crazyramen]

tmore - Yep I only meant that they 'run directly on the crankshaft' as in the governor + lobe are directly on the crank - not timed via the cam chain. My online descriptions of things are greatly hampered by lack of proper terminology and inability to point at things when I talk.

The other day I took everything apart and purposely misaligned my cams and chain by 2 chain links counterclockwise to see if that would allow my contact plate to rotate enough for the "T" 1 & 4 piston marker to align. It did work. Now I CAN set ignition timing correct, with the contact plate fully rotated clockwise. The bike starts and idles even with no choke when warmed up but sounds completely different and bogs down upon throttle.

I'm quite confused why adjusting the cam timing impacts the ignition timing unless we're wrong about it running independently of the cams


Regardless, this fella has the same problem and he says that it's indicative of the points being worn
https://youtu.be/xZ17Omfd3VI?t=1208 - gets good at the 20 minute mark

Kinda wild to me that this isn't anywhere in the Suzuki or Haynes manuals... I guess this was just common knowledge back when points were the only ignition system?

Also would buying a cheap Ebay electronic ignition cure my lack of ability to rotate the contact plate?

My understanding is that they're all DynaS knockoffs and come with the part to replace the lobe on the governor with a rotating magnet and a part that replaces the points with the magnetic pickup - which I'm familiar with from chainsaws and other modern small engines.

Here's a video of someone doing the swap on a Honda.
https://youtu.be/kqyGE_EBcGc?t=408 - start at the 7 minute mark

Edit: I ordered some Daichii contacts and will update when I install them.

[Rijko]

...... My understanding is my governor assembly may have a problem even with static timing if its lobe has become worn or miss shaped ..........

With static timing, you are moving the crankshaft very slowly.

The mechanical advancer needs rpm to start functioning, so it is not in play doing static timing.
Like slinging a rock on the end of a rope.
If you do dynamic timing, the engine is running and the advancer will be working, usually up to around 2.5K when max advance is reached.
Not sure about your bike, just approx ...

BTW i have never seen a mechanical advancer with worn lobes on any GS.
Arms stuck due to lack of grease on the pivots, yes

[Rijko]

Edit: I ordered some Daichii contacts and will update when I install them.

yesterday i worked on a GT750 with 2 out of 3 pickup sensors blown.
Put a point setup in and it fired right up.
I do like electronic, but prefer points...

[crazyramen]

yesterday i worked on a GT750 with 2 out of 3 pickup sensors blown.
Put a point setup in and it fired right up.
I do like electronic, but prefer points...

Yeah I've occasionally had pickups die on chainsaws as well. It is kinda nice to just be able to do a straight up replacement and not have to fiddle much with timing, but it's definitely a bit more expensive than just swapping points.

Kinda seems like the idea of carbs vs fuel injection where one takes more maintenance but is less expensive to fix

[oldGSfan]

It can be tricky to static time a hall-effect EE ignition. I managed recently by using an extension plug lead from an old Actron engine analyzer, hanging the plug down next to the degree wheel, and filming it in slo-mo with my phone on a tripod as I kicked the bike over to get some spark. It worked but was a pain and made me use up some brain cells.

[tmore5585]

Crazyramen: That install video you sent is now making me start to more seriously consider buying a electronic ignition.It looks like the contact plate has a wide rotation sweep which is what I need. Hard to believe China cheap ones are only $34.now on Ebay. The DynaS are $180 or so. Several users seem to be happy with the knockoffs so far. Need to make sure my AAA motorcycle tow membership is paid. The Urban Monk YouTube video you sent me is why I decided to buy another aftermarket breaker point set hoping it would fix my timing problem. I actually contacted him through his website months ago and he responded saying he was to busy at the time to read over/ research my timing questions.
I would not necessarily say the cams run independent of the ignition timing they just do different things and are connected by the advance governor when it fits specially into its slot at the end of the crank and the breaker points are gaped off of its lobe.When the point(s) gap closes a signal is sent to your coil(s) to ignite the spark plug.
Purposely misaligning my cams 2 chain link counterclockwise was a experiment that yielded results I was expecting with ignition timing now being able to be set at "F" marker but probably a bad idea to leave it that way. Let me know if your new contact points fixes your timing problem. Did you buy the(ND) Nipponese points? Your photo looks like that type. My bike uses the Hokusai points. These vintage Suzuki bikes use both and they are a completely different fitment. I learned this the hard way several years ago and apparently still learning the hard way.
RijkoAs as far as I can tell there is not a problem with timing advance just the ability to rotate my GOVERNOR ASSY far enough to reach the "F" marker ether with engine running "lobe timing" or rotating engine with socket BY HAND "static timing)I here you about the GOVERNOR ASSY lobe being worn down. Most likely not my problem