860 Timing Problem

Hello,
I have messed up my timing and I don't understand why.

Since I received my 860, it always ran rough above 1500 RPMs and the timing advance seems to be operational so I decided to check the timing. When I set the flywheel to 4 degrees, the rotor was pointing at the wire leading to cylinder #4 (closest to the steering wheel), not cylinder #1 (closest to the radiator). When I removed the spark plug from cylinder #1 (closest to the radiator), the piston looked like it was almost all the way up so everything seemed to be making sense.

Instead of just changing the position of the wires on the distributor cap, I decided to make the firing order match the cap. When installed on the distributor, the left most terminal on the cap has a "1" stamped beside it so, to avoid future confusion, I wanted the #1 cylinder to be plugged into the #1 terminal on the cap. I removed the distributor and repositioned the rotor so it was pointing at the #1 terminal on the cap. I then attached the wires in the 1-2-4-3 firing order.

Now the tractor won't start and gives an occasional "burp" from the carburetor. This "burping" caused some gas to spray out past the air cleaner hose, on to the starter. After reading many posts on here about setting static timing, it seemed pretty straight forward to me but I obviously misunderstood something. I know the timing is way off now but I don't understand why, what did I do wrong? Thanks.

-Mike

When cylinder 1 was near the top it probably wasn't on the compression
stroke. Bring cylinder 1 up to top dead center when it **is** on the
compression stroke. Then install the distributor to point to #1 spark
plug wire. You can choose which hole to put #1 spark plug wire into
to get things lined up how you want as long as the firing order is
observed for the rest of the plugs.

The last line of my previous post may have been confusing. You can choose which hole to put #1 wire into **as long as** the distributor is subsequently installed so that the rotor points to #1 when #1 cylinder is at TDC on the compression stroke and the firing order is observed for the rest of the wires.

Never mind what is on the flywheel.
Flywheel can be changed or bolted on
wrong (In some cases). Pull #1 plug,
place finger over plug hole, turn
engine until you feel compression,
take screwdriver or wire and put in
plug hole and turn engine BY HAND
until you feel piston at top of bore,
(should be able to feel piston top
out and start back down then back it
up to top). Then set distributor
wires with number 1 just behind
rotor. (Just fired). Then with engine
running check timing with timing
light. (If you can't see marks,
flywheel is on wrong). Hope this
don't confuse you even more.

The flywheel goes on an 860 one way, and one way only. Number one and number four piston are both at top dead center at the same time . The distributor turns half the speed of the crankshaft. You want wire out of the number one distributor hole to number one spark plug. Thus the distributor rotor has to point at number one on the cape with the number one cylinder on compression stroke .Compression stroke is when your finger is pushed out of number one spark plug hole as you turn the engine. When you see the timing mark with number one at top compression stroke the distributor has to be pointed at the terminal on the distributor you wish to be number one. In this case you are a half a round off with the distributor,. So pull the distributor and put it back in with the rotor matching number one terminal.

Wayne,
The way you described it is the way I thought I did it. Once I located the markings on the flywheel, I had to use a screwdriver to rotate the flywheel clockwise until I got down to 4 degrees. I know this was the compression stroke for cylinder #1 because, as I manually rotated the flywheel, I kept an eye on cylinder #1 through the spark plug hole and the piston kept creeping upward.

Once the flywheel was at 4 degrees, I turned the rotor to point at the terminal on the cap marked with a "1" and then I connected the spark plug wire from that terminal to the cylinder #1 spark plug. The next terminal on the cap, going clockwise, went to #2, next #4, and last #3.

You said piston #1 and #4 are TDC at the same time and, before I changed anything, I think cylinder #4 was firing when #1 should have been firing.

If I'm at 4 degrees on the flywheel with the rotor pointing at the #1 terminal on the cap and that terminal is wired to cylinder #1, why isn't it working? I feel like I've done everything right but, like I said, obviously I didn't. I think I can put it back to how it was before but then cylinder #4 would be firing at 4 degrees which wouldn't be right.

Thanks for all of the responses so far.

-Mike

(reply to post at 17:49:14 01/24/18)

Click to expand...

"...before I changed anything, I think cylinder #4 was firing when #1 should have been firing. " Not the case, as when #1 is in position to fire (compression stroke), #4 is on exhaust stroke & would have no mixture to fire.

The 4 degree timing mark will show weather number one or number four is on compression stroke. When the crankshaft was turned a full turn the distributor has turned only a 1/2 turn. Yes, you can literally make any one of the four terminals as number one. But you want number one at the designated number (bottom left) ,So with number one cylinder( front one) on compression stroke the distributor rotor has to be pointing at the bottom left of the distributor.

Wayne & JMOR,
You know, I thought cylinder #1 was on the compression stroke when I was at 4 degrees but I didn't realize that the distributor only rotates half as fast as the flywheel. I thought cylinder #1 was always at 4 degrees during the compression stroke.

I also know I watched cylinder #1 going up while I was manually adjusting the flywheel but maybe I'm mis-remembering and it wasn't during the final adjustment that actually put me on 4 degrees, it took me a while to finally find the numbers through the flywheel viewing window.

It would make sense that I did set the flywheel to 4 degrees but on the exhaust stroke instead of the compression stroke. I'll take a look at it tomorrow and report back. Thanks for helping me make sense of this, I honestly don't know what I'd do without this forum.

-Mike

Wayne,
I forgot to ask, if I have my timing incorrectly set on the exhaust stroke for cylinder #1, would I be able to fix my issue by turning the rotor 180 degrees? Thanks again.

-Mike

"if I have my timing incorrectly set on the exhaust stroke for cylinder #1, would I be able to fix my issue by turning the rotor 180 degrees?"

Not by turning just the rotor cap, but taking the distributor out and turning 180 would do it.
Assuming of course, that it is off exactly 180 degrees.
I would start over by setting #1 on compression stroke as noted.

The distributor has to be pulled to rotate the shaft & rotor and the distributor goes back in the same place it always was. And I agreed with Royce. I would not time 1/2 the system half off.

The timing mark passes the sight hole 2 times for every 1 time a cylinder fires.
Once on the compression stroke and once on the exhaust stroke.

If you want to do it right.......
Pull the distributor back out.
Remove the #1 plug.
Bump the engine over while you hold your finger in the #1 spark plug hole.
When you feel compression the mark should be close to the sight hole.
Turn the engine by hand till 4&#176 lines up with the mark.
Install the distributor to where the rotor is pointing at #1 plug wire.
Rotate distributor to where the points are just starting to open.
You have just static timed the motor.
You can fine tune it with a timing light or by ear.

AMEN

John, Wayne, & Royce,
Sorry for not being more specific. When I asked if moving the rotor 180 degrees would fix my problem, I knew that would require removing the distributor in order to turn the rotor.

I plan to fix it the proper way, as John explained, I just wanted to know if I understood the issue correctly that the rotor was pointing in the opposite direction than it should be pointing.

Learning that the 4 degree mark is visible twice for every single rotation of the rotor make all the difference. Thanks to you guys, I now understand the issue and will be able to fix it today.

-Mike

Ok, I got the flywheel back on 4 degrees on the compression stroke for cylinder #1 but I have another question.

Because of the gear on the bottom of the distributor, it will obviously only go in with the rotor button pointing in specific directions. The shaft just below the gear has a hex shaped hole that lines up with a rod down inside the tractor. I can get the rotor button to line up perfectly with the #1 spot on the cap and the oiler in the center but it won't fully seat because the hex rod isn't lining up with the hole. I can set it in the next gear grove in either direction and it will sit flush but the the outside of the distributor needs to be rotated to the point where the oiler is far to the left or right, not in the center.

You guys are probably laughing right now because who cares if the oiler is in the center, right? I just assumed that, from the factory, the oiler was in the center so that's what I was trying to duplicate. I don't supposed there's any trick to making that hex rod line up so that the oiler is in the center, is there?

-Mike

The hex rod drives the oil pump. The distributor drive gears are helical, so the shaft turns a bit as the teeth mesh as the distributor is inserted.

Then, it will sit on the oil pump shaft, if the hex doesn't happen to match up.

Slowly crank the engine while gently pressing down on the distributor and the hexes will match up and the distributor will move the rest of the way into place.

Then, back it up a quarter-turn or so and again bring it forward to the timing marks and note the rotor position and, if not OK, gently lift the distributor up enough to get the gears just out of mesh, and advance or retard it a tooth (as needed), and try again.

Bob,
Fantastic, I knew there'd be a trick! So, with the oiler in the center and the distributor sitting on top of the hex rod, I can manually rotate the flywheel with a screwdriver until the hex hole lines up and drops down to sit flush, right? I'm gonna go do that now. Thanks for everyone's help.

-Mike

Success!!! My 860 is running better than ever, I couldn't be happier! I owe it all to the help I've received on this forum, I really appreciate it.

Fixing the timing resolved many of my other issues. I previously re-routed my fuel line because the stock fuel line was getting so hot that the tractor would shut off and I would get a bunch of bubbles coming up into the tank from the fuel line. The tractor would also surge and backfire if I tried to go past 1500RPM.

Now I can easily get the tractor to 2200RPM and it sounds great! Not only that but my temperature is a LOT lower than it was before. Previously I couldn't adjust the carb with without wearing a heavy glove because it was so hot on that side of the tractor but I adjusted the idle today without the need of a glove.

Again, I can't thank you guys enough, this forum is invaluable!

-Mike

Glad to hear you got it all worked out.