REC

Managed to sort it, the drive chain was running slack, which caused poor alignment of the shaft the clutch is on.

There was a fair bit of end float on my engine, I ended up using 5 M13x0.3mm shims to eliminate it so the job is defintely worth doing. Hopefully the photos are useful for anyone else doing the same job.

Thanks for all your help Wristpin.

After a long wait the new roll pins turned up so finally back together with all end float eliminated.  Unfortunately I now have the opposite problem of a dragging clutch.  Even if I fully slide the two halves of the clutch apart by hand I  cannot get it to fully disengage. 

I have tried moving the engine around slightly on its mounting holes without any improvement.  Could adding too many shims have possibly caused this? From what I can tell, inserting shims should not have caused the dog on the engine to move away from the engine casing. In addition the engine turns over easily so I'm sure I haven't caused any binding. 

Luckily the pin had snapped clean in two, and was only underneath the crankshaft counterweight. Also found the clutch was loose on the shaft so punched the pin out which came out in several pieces so new pins for both ends of the shaft ordered!

Compared to the Honda GV150 engine that my old Haytertte had, the B&S doesn't seem as well made; I was quite surprised that most of the shafts are running direct in the aluminium castings. Also wasn't impressed that the APTO gear has to be removed to get at one of the sump bolts!

Not too difficult to remove the sump and I was pleased to find that the what I intitially thought were snapped bolts were just locating pins. Predictably the gasket didn't survive the sump being removed! Looks like the shimming of the shaft won't be before time...

General view of inside the crankcase but no obvious sign of the other half of the pin. I'll be getting the dentist's mirror in there

So just need to order a new roll pin (3/16x15/16" looks ideal but I'll probably have to get 7/8" or 1") and a new sump gasket to finish the job. The only question I do have regarding the clutch adjustment is that it seems to be impossible to remove the red sleeves over the clutch when everything is in place so do you determine when the dogs are touching by feel?

Update as I finally got round to starting this job after ordering a new clutch cable as the original was frayed. Hopefully the photos will be helpful to anyone else doing this job

I was pleasantly surprised when the friction disc slid off easily after a week's soaking in Plus Gas, so the engine was duly removed. There are some signs of rounding and wear on the clutch dogs but hopefully this job will arrest any  further wear a bit.

Keyhole cover removed and bronze gear exposed.

As the gear was a fairly tight fit on the shaft I initally thought the roll pin was still holding everything in place  so unfortunately ended up knocking the roll pin right through. Fortunately it was rescued with long nosed pliers. You can just see it siting on the gear below the APTO bush

Then discovered the pin had sheared. So I've decided to take the sump off to check the other half is not in there somewhere

Thanks for the clutch adjustment details. Hopefully I'll get a chance to look at it this weekend; will update when done.

Thanks for such a detailed guide, I'll see how I get on.

Just have to see how getting the friction disc off the crankshaft goes...I have a nearly new can of plus gas...

Many thanks for the information. There is indeed some end float. I will get the porthole cover off and check the shaft diameter for the shim. 

I assume you still had to get the engine off the deck or remove the driven half of the clutch to move parts along the shaft,  or did you keep everything in situ?

Hi all

I have a Hayter Harrier 2 and I am mindful of needing to keep the dog clutch correctly adjusted. How do I check the adjustment of the clutch given that the red plastic sleeve prevents me seeing the engagement/condition of the clutch?

I presume that adjustment is done by the nut on the threaded post next to the operating fork.

Thanks