Rear Cylinder not Firing

New plug did nothing, and looks like there is no spark. I checked for voltage on the primary side of the coil and there was 10.5v which increased on cranking the engine. The front cylinder coil exhibited exactly the same behaviour. Just found the service manual online so haven't checked the resistance on the coil (it's dark now) so will have another look tomorrow. To me the coil is starting to look highly likely?

[Messie]

I'm a mechanical numpty, but even I'm pretty certain that on a twin cylinder engine there are two plugs.

You need to look for and find the second plug.

Unless it's a single thingy that you're not telling us about

No the front runs ok, just the rear that's gone, so it does have 2 plugs but not in the same cylinder.

I think my next plan could be to connect the front coil leads to the rear coil and see if I get a spark. If not in think I could be pretty sure it's the coil.

Ok so have checked the coil resistances and it seems to be in spec. But in comparison though the rear coil only reads 2.7ohm compared to 3.8 on the working front (primary winding). Do you think it could be breaking down further under load causing the issue?

Have also checked continuity of all wires and grounds. Everything seems to connect where it should and I have similar voltage on both coils. I am going to order a coil and fit it, hopefully that will sort the issue.

[jambo]

Can you not unbolt the front coil, move it to the rear and check it that way?

Jambo
Sent from my thingie

I removed the rear coil so i could try it attached to the fronts primary inputs. Just need to ground it to the frame somehow. Didnt fancy taking the front off as it looks even tighter to get to than the rear (and that was a pain).

Replacement coil and the rear cylinder is now working. Moral even if its within spec it can still be faulty!