SH86 not starting.

[Gerbutt]

Hello all, hope you are well?

 

I have a SH86 blower that’s not starting. When I got it it wasn’t sucking fuel up with the primer bulb so I’ve stripped the carb, fitted new kit and also fitted a new flange where the primer bulb is. When I ordered the flange I ordered the other option for the carb accidentally, but the only difference seems to be a breather pipe coming off the back. The original has just a hole without the pipe. I fitted it all, it sucks fuel up fine but still won’t start, just splutters every now and then.

 

I’ve now swapped the carb with a known good one and it still does the same. It seems to have a good spark, it’s the same as the running machine. I’ve taken the exhaust off and the piston looks mint. I’ve taken the flywheel off to check the key and that’s fine. I did notice some red sealant around the crank seal. Would a major air leak cause it to not start at all? The seal doesn’t look bad to the eye but I know they still can be.

 

Any ideas?

[spudulike]

Leaking seals generally have a bit of black fluid around them if they are that bad. Mostly engines will start with a dodgy seal and have had saws start with the seal completely missing!

If you have tried the carb and ruled it out - I say this a bit tongue in cheek as I have heard it all before and carbs are probably the most likely cause, try the coil as they can spark but the spark can be timed all wrong. I have had a blower idle perfectly but as soon as you rev the engine - pop, nothing and it was the coil high speed advance blown so it would just die.

If the thing has compression then it sounds coil/plug orientated but that is if your carb swap was as it should be.

Don't rule out split fuel lines and dodgy fuel filter as well plus the muffler can sometimes wet plugged with carbon etc, worth checking.

[Gerbutt]

The carb I’ve put on is off my bg86 and this is a sh86 but they look the same. The air glitter set up is slightly different but I can see that making a difference.

I’ve just put the coil on but it’s the same, it just pops once or twice in around ten pulls. I’ll try the plug tomorrow. The carb is pulling fuel up into the primer well. I’ll try a bit of carb cleaner through the carb inlet and see if it fires with that.

Does the fuel filter set up with the two pipes just pull out the top of the tank?

Thanks for your advice so far [emoji106]

[Gerbutt]

It was the plug spud. I’d have just assumed it was ok as was sparking, so thanks for that [emoji106]

[spudulike]

Glad you sorted it, these small plugs appear to be less reliable than the 14mm ones, catches me out now and then!