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Collection, Preservation and Display of Old Lawn Mowers

B24 Royale with Tecumseh engine - not running well


I have a Atco B24 Royale with Tecumseh engine (original Carb) it runs, but the engine speed is difficult to regulate (only works with the choke set to the max and throttle set half way), it is either ticking over and runs slow or runs too fast. also it seems to changes speed automatically without changing the accelerator?. It feels as its a carburettor setting is wrong or dirt in the fuel, but have no idea how to either check/change the settings on the carb or clean, or could it be that the timing mechanism is breaking down ? any advice welcome


wristpin Mon, 13/05/2013

You don't say what Tecumseh - I'm thinking an H50 or 60?

For all intents and purposes the timing is fixed - unless you have been fiddling!

Almost certainly it's a carb problem so either give it a thorough clean or, preferably,  take it to someone with an ultrasonic cleaning tank and get them to give it a couple of sessions in a hot detergent solution.

If it is the carb fitted to the H50/60 be warned that if it has been left with contaminated/stale fuel in it for any length of time even ultrasonic cleaning may not recover it. We used to renew one or two a year that would not respond to cleaning.

Dave C Mon, 13/05/2013

Thanks, I have a spare engine so will tak the carb of that and clean it and then fit it, ps how do i tell if the engine is a H60 or 50

wristpin Tue, 14/05/2013

Usually stamped into the tin shield over the cylinder head  but sometimes on a tag secured by one of the valve chest cover screws.

The carburettor itself will probably have some id letters and numbers - often stamped into the edge of the flange where it mounts to the manifold adaptor.

Why not post an image? - always useful with this sort of enquiry.