Restoring a Garaged 1979 GS850 - Part II, it won't start

[hcaz]

Hey Folks,

Following up on my initial post here from a month ago:

Restoring a Garaged 1979 GS850


I've cleaned a lot, replaced a lot, and still can't manage to get the engine running. This is a list of everything I've done so far:

All the work I've done so far:
Valve/Tappet Clearance - I didn't change anything, because this was within spec
Cylinder 1 Intake: 0.04mm
Cylinder 1 Exhaust: 0.07mm
Cylinder 2 Intake: 0.06mm
Cylinder 2 Exhaust: 0.08mm
Cylinder 3 Intake: 0.08mm
Cylinder 3 Exhaust: 0.07mm
Cylinder 4 Intake: 0.04mm
Cylinder 4 Exhaust: 0.06mm

Compression Test - This seemed like it was on the low end, but should be good enough to start
Cylinder 1: 150psi
Cylinder 2: 130psi
Cylinder 3: 130psi
Cylinder 4: 130psi

Spark Plugs
- Installed brand new NGK B8ES spark plugs, gapped to 0.031" (0.8mm).
- I visually checked the spark on all four plugs with the new ones installed, and it appears to be bright blue

Battery
- Installed a brand new battery and have been using a battery tender to keep it fully charged.
This is the battery I used: https://www.batteriesplus.com/produc...ultra/cyl10004
Voltage across the terminals while turned off: 12.54v
Voltage across the terminals while hitting the starter: 11.45v

Gaskets
- Installed all new gaskets for the carbs
- Installed new valve cover gasket after checking the tappet clearance
- Installed new breather cover gasket

Carbs
- Fully pulled off the bike and disassembled them, and dipped each of the carb parts (including the carb housing) individually in Berryman's carb cleaner excluding any rubber o-rings and the floats.
- I followed this guide for the carb clean, and removed every jet/screw and individually sprayed them with carb cleaner followed by compressed air.
- Installed all new o-rings
- Installed new boots between the engine and the carbs

Fuel Tank
- Added Sea Foam to the fuel tank, completely drained it, then filled it with fresh gas. There was no rust inside the tank.
- Replaced the petcock with a new one that is not OEM - it functions fine as far as I can tell, but slightly leaks around the screws. I have a new (OEM) petcock ordered that I will replace this with.

Oil/Oil Filter
- Replaced oil with Shell Rotella 15w40
- Replaced oil filter with K&N 133

Air Box
- Completely cleaned the airbox of all the old gunk inside
- Replaced the airbox intake boots with new ones
- Added new weatherstripping around the air filter to seal it inside the airbox- Installed new oiled air filter

Contacts/Points
- Checked and adjusted for clearance per the GS850 Service Manual

Hoses
I replaced the following hoses:
- Fuel line from gas tank petcock to carb intake
- Vacuum hose from carb to petcock
- Four carb overflow hoses
- Two carb vent lines

Exhaust
I removed the exhaust and polished it, although I don't think this would affect whether or not the bike starts.

Non Engine Related
Replaced tires
Brakes: I haven't gotten far here yet, but I've ordered new brake hoses and cleaned the front two calipers.
Replaced bent clutch lever
Derusted the handlebars, fairings, exhaust, etc
Removed most fairings and bodywork that prevents working on the bike

Non-Engine Electrical
Replaced the left handlebar switch and cleaned the right handlebar switch contacts. Prior to this cleaning, I could not get my turn signals to work or the engine starter button to work.
Replaced the turn signal relay. Before this was replaced, my turn signals would not flash and would only stay lit.
Replaced the wire running from the oil pressure switch to the wiring harness. It had been chewed through by something.


How I've tried to start the engine:
Set the petcock to PRIME after rebuilding the carbs, wait ~1 minute, set the petcock to RESERVE. Pull the choke fully out (I'm waiting on a replacement cable for this, but I have a friend manually pull the choke cable fully)
Hold in the clutch lever, press the starter button.
This is what ends up happening:

https://drive.google.com/file/d/18Fq_iRUbgxbP2eCMfnyLUwxfZY0K6o1S/view

I've also tried the kickstarter, but haven't been able to get it to start either way. When I try the kickstarter I make sure it's in neutral and the clutch lever is out. When I use the electric start I hold in the clutch lever and keep it in neutral.
I tried spraying some starter fluid into the airbox, but it hasn't made a difference.

Things I've checked after putting everything back together:
- After priming the carbs, I emptied the float bowls into a container. All four carbs are filling up with fuel.
- None of the carbs are leaking.
- The spark is still good on all the plugs
- The petcock functions as it should - I took the tank off the bike, and tested all three positions of the petcock draining into a gas can.
- Replaced the starter relay with this one from eBay

I'm running out of ideas beyond just recleaning the carbs again - any ideas? I noticed I forgot to throw the clamps back on the airbox boots between the carbs and airbox, but that's about it.

[hcaz]

Here's a quick before/after of derusting the bike:

[steve murdoch]

It is certainly turning over with gusto.
I didn't know the 850 had a starter cut-off switch integrated in the clutch lever.
Something simple like the kill switch getting jostled when you were cleaning it?

[hcaz]

It is certainly turning over with gusto.
I didn't know the 850 had a starter cut-off switch integrated in the clutch lever.
Something simple like the kill switch getting jostled when you were cleaning it?

As a quick test, I tried a few more things:

- Electric start with the run/off switch on the right handlebar switched to "off", it did not crank
- Kickstart with the clutch pulled in, it did not crank
- Electric start with the clutch left out, it did not crank

The only way it cranks over like in the video is if the clutch is pulled in, even in neutral

Something interesting I did also test... I noticed in the Clymer book I have in the "Troubleshooting" section that the contact points, when pulled apart, should produce a spark. Mine aren't always producing a spark and when they do, it's not that strong. I accidentally bridged the gap of the points with a screwdriver, and heard a loud 'boom' through one of my exhaust pipes. I think there was fuel leftover in there from trying to crank, and bridging it with the screwdriver caused enough of a spark to ignite it.

My best guess is the contact points are worn and not sparking correctly - I can still see spark on the spark plugs, but it's hard to know if it's "every time it should be there" vs just "it's there" when I'm hitting the starter button.

Just thinking out loud, but could this be caused by bad/weak ignition coils, a wiring harness that wasn't fully cleaned, or worn contacts?

For some more info, I took photos of my contacts - something tells me they shouldn't look like this:

https://imgur.com/a/1N6RkwV

[Nessism]

Did you check spark on each cylinder?

[Redman]

It is certainly turning over with gusto.
I didn't know the 850 had a starter cut-off switch integrated in the clutch lever.
Something simple like the kill switch getting jostled when you were cleaning it?

Clutch swtich would cutout the starter solenoid.
Kill swtich would cut out the igntion AND the starter solenoid.

ANd in this case the starter solenoid / starter is running, so . . . . .

[hcaz]

Did you check spark on each cylinder?

Yes -- I see a spark for every cylinder, but after looking at the contacts, it's hard to know if the spark is there every time or just occasionally. I'm going to replace the contacts and see if that fixes it

[phydeauxmutt]

Points would be my first suspect. Check the price of points (AND condensors), compare that to a Dyna electronic replacement.

Points require maintenance, adjustment and replacement. The Dyna unit is pretty much "set and forget" unless it outright fails, which does happen, but not very often.

[Peter#1266]

You are not actually trying for a spark at the points - the purpose of the condenser is to inhibit the spark when the points open. Excessive sparking at the points erodes material from the points surface.
What are the O rings between the cylinder head and the inlet manifold stubs like? Could be an air leak there.

[rphillips]

Possibly got the ign. timing is 180 degree out. Won't work if firing when at TDC of on ex. stroke instead of compression stroke. Just a thought. & good luck.

[hcaz]

Points would be my first suspect. Check the price of points (AND condensors), compare that to a Dyna electronic replacement.

Points require maintenance, adjustment and replacement. The Dyna unit is pretty much "set and forget" unless it outright fails, which does happen, but not very often.

I checked and adjusted the points, it was only $30 on eBay for a new set. I don't want to dump money into this bike, but I want to get it running with original equipment first. I'll likely still switch over to an electronic ignition, but it's easier in my head to figure out "why isn't the bike running with original equipment" vs "is it this mod I tried to install that is preventing it from running or other old parts that aren't fixed yet?".

You are not actually trying for a spark at the points - the purpose of the condenser is to inhibit the spark when the points open. Excessive sparking at the points erodes material from the points surface.
What are the O rings between the cylinder head and the inlet manifold stubs like? Could be an air leak there.

The O rings between the cylinder head and the inlet manifold stubs are brand new, just replaced them.

Possibly got the ign. timing is 180 degree out. Won't work if firing when at TDC of on ex. stroke instead of compression stroke. Just a thought. & good luck.

Thanks -- the ignition timing was definitely off, when I corrected the points gap (which was really far apart, 0.5-0.6mm when it should be between 0.3mm and 0.4mm) I also set the timing.

After a lot more poking and prodding the ignition timing and points, I think they were "a" problem but not the only one I had. I can now get the engine to briefly run off starting fluid alone, and it will continue running assuming someone keeps spraying starting fluid into the carbs.

This leads me to think in the four main areas of "fuel, air, compression, spark" needed to run an engine, I definitely have fuel related problems. I tested the petcock replacement I bought multiple times off the bike, but it was a cheap non-OEM part. I ended up buying a new OEM petcock that I'll install soon -- after installing that, my next plans are to inspect everything involved with getting fuel into the engine in a proper mixture.

[hcaz]

Sure enough, after doing a proper bench sync of the carbs (which I didn't do before), swapping the contacts and gapping them correctly, and installing the factory OEM petcock, it starts up. After running with the choke for 5-6 minutes and a box fan pointed at the engine, it revs up, idles, and runs with the choke off with no issues.

Now that the engine can spin the wheels, I need to work on stopping the wheels by fixing the brakes.

I ordered some replacement brake lines that are now installed, and have cleaned all three brake calipers. It took nearly 80psi to remove the pistons from the rear calipers, but eventually they came off.

Final steps I think before going on a test ride to the DMV for registration:
- Front headlight/turn signal installation (I likely won't be keeping the Vetter fairing, it's too large)
- Full carb sync (I ordered a Morgan Carbtune for this bit)
- Hose/cable routing (Up to this point I've focused on getting it running, not making sure hoses/cables don't get snagged while riding)

Once it's running and registered, I plan on doing another disassembly/reassembly to do a deep clean and focus on the cosmetic aspects of the bike like the seat mouldings which are somehow $100: https://www.ebay.com/itm/17480341723...AAAOSwCydgyBjC

[Big T]

Hose/cable routing is shown in the factory service manual
While you're waiting, adjust those 2 .04mm valves up to .07-.10

[Redman]

Hey ! Good to hear of the progress.

A further note: Yah, the condenser is not really required to make the spark at the sparkplugs, is there to prevent/reduce the spark at the points.

[hcaz]

Hey Folks! For another update, I have the bike fully registered and running. It's not perfect, and could still use more work, but it's wild to see it on the road and running really well given its age.

To follow up on the points from before:

- Front headlight/turn signal installation (I likely won't be keeping the Vetter fairing, it's too large)
- Full carb sync (I ordered a Morgan Carbtune for this bit)
- Hose/cable routing (Up to this point I've focused on getting it running, not making sure hoses/cables don't get snagged while riding)

I'm a bit annoyed that the only turn signals I could find were off a 81'/'82ish GS, but it's still technically a 'stock' Suzuki part.

I did a full carb sync with the Morgan Carbtune. It's an incredible piece of equipment, and it was insane to see:
1. How much it made a difference
2. How such a small screw turn made on the sync, and how hard it was to tighten the lock nut without moving the screw
3. How much an actual carb sync tool was worth the money, even if used only once.


Some more problems/things to fix:
- I never changed the gear oil, fork oil, or the final drive unit oil. I'm assuming that those need changed since they haven't been changed in decades
- The tachometer cable and speedometer cable are not in the best condition. The tach cable used to cause a whine until it was lubricated, now only the speedo cable causes a whine (even after lubrication)
- The speedometer jumps around a bit while riding, sometimes jumping up to 100mph while riding 30-40mph. I've stopped riding the bike until I get this fixed, because I assume it runs up the odometer quicker than normal
- The brake lever and reservoir are a cheapo purchase off Amazon. I can't seem to find a '79 GS850 reservoir in good condition, and the one I had was too far gone to be worth using. The $20 lever/reservoir I bought off Amazon works fantastically, including the stop lamp switch, but I'm not a huge fan of how it doesn't match the clutch lever.

I've ordered replacement speedometer and tachometer cables, hopefully that will solve the whining/jumping/etc.

Here's a photo of the bike over at Deus Ex in Los Angeles, CA: