Briggs 21 HP is hard to start

Scrubcadet10

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You must have a beefy starter then.....:laughing:


BTW couldn't find any engine with that model number.

And you mean the valve clearance closed up?

Valve timing relates to cam and crank gear.

Anyhow glad you got it up and running:thumbsup:
 

Tinkerer200

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Well just to clear things up a little, the 33 series engine should have the mechanism on the cam and will result in very slight movement of the INTAKE valve just before TDC on compression stroke. You should be able to see it if you watch very closely while turning the engine by hand or feel it if you hold the valve steam or rocker arm. These do fail fairly often, broken arm or spring.

The V twin 40 series engine problem should have been a separate post to avoid confusion. It will not have the mechanism on the camshaft. It will utilize the "easy spin" cam shaft grind which holds the INTAKE valve very slightly open well into the compression stroke. Valve timing is the wrong term for valve clearance which is critical for the easy spin cam to do its' work. The extremely small difference in valve "timing" makes no difference.

Walt Conner
 

Neo7

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Absolutely Walt "valve clearances" is the correct term. Sorry for that error on my part.
The engine model number is correct .. maybe it's hard to find because it's an Australian variant.
 

Tinkerer200

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Absolutely Walt "valve clearances" is the correct term. Sorry for that error on my part.
The engine model number is correct .. maybe it's hard to find because it's an Australian variant.
Very common engine, correct number is 407777, got one on our Dixon Estate mower and another one on the shelf, rebuilt, traded and sold a bunch of them.

Walt Conner
 

bertsmobile1

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Check the head bolts have not come loose
Also measure the height of the valve guide
They are also notorious for shifting.
 

bertsmobile1

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Thanks for the tip ... I'll do these things for sure :thumbsup:
FWIW we do not get "Australian Models".
However what is sold down here can be either the USA Spec, the Californian Spec or the European spec ( Metric engines )
What generally happens is a model fails in a particular market so they dump them down here, or there is a safety / emission change so a particular model is unsaleable in it's destination market so they get dumped down here.
Husquvana in particular regularly does this
 

Tinkerer200

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So what happened to OP's 33 series engine which got lost in the confusion?

Walt Conner
 
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