Hayter Heritage Tractor 13/30 CODE131C WITH Briggs and Stratton 12.5 HP I/C

[Ray Pooley]

Hello forum.

Back again.

I'm trying to get this machine up and running for an elderly neighbour who is currently pushing a lawn mower around his large gardens.

He had this machine given to him for nothing.

It has been standing idle outside under a tarp for decades.

Story so far.

This machine was dead. No crank.

New starter solenoid (old one cracked at the battery terminal).
New starter fuse holder and 15A fuse. (old one had a broken terminal connector)
New seat switch. (old one had broken spring)
New bin switch. (might as well)
New ignition switch. (no continuity through old one)

Engine would now crank but no start.

Checked for spark. No spark.

Replaced plug. No spark.

Checked ignition coil resistance. Should be 2.5 to 5 kOhms

Reads 43 kOhms. Knackered

New ignition coil.

At this point engine now starts and runs but rough.

New air filter and fuel filter.

And here's what it sounds like today. (See link below)

I don't think it's a carb issue.

Maybe timing?

All and any thoughts would be appreciated.

Thanks in advance.

http://86.153.209.5:163/HuntingMower2.mp4

[Mick]

That's definitely a carb / fuel issue, unless it has an air leak. 

What carb is on that machine?

[Ray Pooley]

That's definitely a carb / fuel issue, unless it has an air leak. 

What carb is on that machine?

Thanks for the response.
I didn't get a notification of your response.
Not sure why.
Anyway. No air leaks. Checked the vacuum pipe and added jubilee clip to the carb connection just in case.
I was thinking last night about stale fuel.
I have no idea how old it is.
Do you think that might cause the hunting?
I have no idea what the carb is.
My guess id original equipment.

[Mick]

Stale fuel can definitely cause issues like this, especially if it's been sitting in the can since last season. Always good to start with fresh fuel. 

Notifications, please check your notification settings by clicking on the Alerts button (Top Left) and clicking Settings.

The carb Id, you could perhaps attach a photo or two of the offending item.    If you manually apply a bit of choke while it's running does the surging even out?

[Ray Pooley]

Stale fuel can definitely cause issues like this, especially if it's been sitting in the can since last season. Always good to start with fresh fuel. 

Notifications, please check your notification settings by clicking on the Alerts button (Top Left) and clicking Settings.

The carb Id, you could perhaps attach a photo or two of the offending item.    If you manually apply a bit of choke while it's running does the surging even out?

Thanks again. I'll put some fresh fuel in it.
The Hayter manual tells you to apply full choke as part of the start.
I close the choke gradually until it starts to stall.
There is a volume control screw on the carb that I haven't tried yet.
I'll give that a twiddle next time I run it.

[Ray Pooley]

Stale fuel can definitely cause issues like this, especially if it's been sitting in the can since last season. Always good to start with fresh fuel. 

Notifications, please check your notification settings by clicking on the Alerts button (Top Left) and clicking Settings.

The carb Id, you could perhaps attach a photo or two of the offending item.    If you manually apply a bit of choke while it's running does the surging even out?

Just been out and had a twiddle with the volume control.
Not a lot of movement there. Only about 45 degrees.
Made no difference.
What I am seeing is backfire which suggests pre-ignition.
You can see the effect at the inlet and the throttle lever.
There is no way of adjusting the timing as far as I am aware.
So I don't know how this is happening.
The gap between the new ignition coil and the motor is correct at 0.3mm
What do you think?

http://86.153.209.5:163/Backfire1.mp4
http://86.153.209.5:163/Backfire2.mp4

[Ray Pooley]

Stale fuel can definitely cause issues like this, especially if it's been sitting in the can since last season. Always good to start with fresh fuel. 

Notifications, please check your notification settings by clicking on the Alerts button (Top Left) and clicking Settings.

The carb Id, you could perhaps attach a photo or two of the offending item.    If you manually apply a bit of choke while it's running does the surging even out?

Thanks again. I'll put some fresh fuel in it.
The Hayter manual tells you to apply full choke as part of the start.
I close the choke gradually until it starts to stall.
There is a volume control screw on the carb that I haven't tried yet.
I'll give that a twiddle next time I run it.

Stale fuel can definitely cause issues like this, especially if it's been sitting in the can since last season. Always good to start with fresh fuel. 

Notifications, please check your notification settings by clicking on the Alerts button (Top Left) and clicking Settings.

The carb Id, you could perhaps attach a photo or two of the offending item.    If you manually apply a bit of choke while it's running does the surging even out?

I am now beginning to think it might be a problem with the flywheel key.
Broken or crushed. Apparently the TDC on these engines is 0 degrees.
Not much tolerance there.

[Mick]

I'm not saying the key hasn't partly sheared, but to be honest it's unlikely unless the flywheel wasn't torqued down properly. It does to me sound like a fuel issue.  Those engines are prone to hunting and surging unless the carb is spot on. Especially if it's got a NIKKI carb on it.

Is your float bowl attached via two screws at the top of the bowl?  Or one bolt at the bottom?