maybe you can help me out

[pault36]

hi all i've got a bedford mk sat on the shopfloor that has a b81 petrol (stolly)engine bolted to the back end. this drives a winch which is used by the local gliding club to tow their gliders into the air. i'm after any tech info on the b81 as i'm servicing it as a favour in particular anyone know the plug gap as its running pretty rough at the mo and all the plugs are covered in soot and it stinks of unburnt fuel any help setting up the solex carb would be greatly appreciated too.

thanks

Edited November 19, 2008 by pault36

[fv1609]

Sorry I see it's your first post & 73 people have looked at your message & been unable to help. I have no B81 experience, but this is based on the boy's model ie B60.

 

If the plugs are RSN13P you cannot adjust the gap if you do the platinum electrode will very likely ping off. What plugs do you have?

 

There isn't much you can adjust on the carb. Carefully screw in the mixture control screws which are around the base of the carb. Not in too hard as you may damage the tips. Unscrew each by 1.25 turns. That gives you a point to adjust from.

 

Don't use the choke. With engine off 2 presses down on the accelerator, then leave it alone & start up.

 

Test the condenser with a Megger. If that is not available fit a 0.2 mfd Land Rover one.

 

Check the points haven't closed due to wear on the heels.

 

Disconnect the plug leads. Just push them into each plug. with the engine running (watch your fingers don't get electrocuted from centre of lead) & with engine running lift & replace each lead in turn. You should hear the engine labour a bit with a lead disconnected & pick up again when replacing it. If there is no change you have a problem on that cylinder either to fuel getting there or more likely an HT problem with the lead. I have had engines run just on 3 cylinders.

 

Make sure you are using new fuel.

 

Take the side panel off the carb & inspect the accelerator pump diaphragms they may well have split or gone porous.

 

Consider fitting electronic ignition, makes a big difference.

 

When it is warm & running adjust the mixture screws slowly in turn for best smooth running not so much max revs, keep adjusting the distributor position of advance/retard & going back to the mixture controls. Go on & on til it sounds nice.