Briggs 21 HP is hard to start

DJSNOW

Forum Newbie
Messages
1
What is the gap settings on the exhaust and intake valves on a Model 331877; Type 014681; Code 100513zd? Also why won't a new starter "push" past the compression stroke? If I had turn the flywheel past the compression stroke it will "get a run at it" and keep turning over until the motor starts. Help!
 

Travlitt

Member
Messages
28
What is the gap settings on the exhaust and intake valves on a Model 331877; Type 014681; Code 100513zd? Also why won't a new starter "push" past the compression stroke? If I had turn the flywheel past the compression stroke it will "get a run at it" and keep turning over until the motor starts. Help!
You can find all of the engine specs here.

http://outdoorpowerinfo.com/engine_specs/briggs_valve_gaps.asp

Proper valve adjustment of the valves will cure the hard starting problem.
 

Neo7

Well-Known Member
Messages
125
Hi All,

I have the same problem with my 24HP V-Twin B&S (40777-0128-E1)
I recently replaced the Starter Motor and ensured good (heavy gauge wire/battery/charge) connections to the solenoid, motor and negative to case, but it still the same.
I've set the valve timing many times in the past but just to prove the point what adjustments could I make to the vale timing?

Many thanks.
Neo.
 

Neo7

Well-Known Member
Messages
125
"compression release"... What compression release?... Where is the compression release? :confused2:
 

Scrubcadet10

Lawn Addict
Messages
1,272
It's on the camshaft inside the engine.
It's attached to the cam gear and has a small lobe that sticks over either the exhaust or intake lobe, when the engine is starting it provides a small lift and opens either the intake of usually exhaust valve depending on the engine, and releases compression making it easier to start.
Then when the engine is up to idling speed, by means of centrifugal force the mechanism pivots out of the way of the cam lobe and lifter.
https://www.youtube.com/watch?v=tceKAAViC1c
 

Neo7

Well-Known Member
Messages
125
That's a great feature Scrubcadet but regrettably that's not my engine. I recently rebuilt my engine (spent many hours in there lol!) and I saw nothing that could provide compression release.
Maybe I have caused some confusion here because my engine is the 24HP V-Twin (40777-0128-E1).
 

Romore

Well-Known Member
Messages
133
There will be a spring loaded flyweight on the camshaft, it has to operate freely.
 

Neo7

Well-Known Member
Messages
125
No there's definitely no spring loaded flyweight on the camshaft of an Intek V-Twin Engine.
But nonetheless the problem is solved :wink:

It was the valve timing... This is what happens when you live in denial :laughing: ... As mentioned I rebuilt the whole engine only a few months back and with minimal use I couldn't believe the valve timing had changed in that time. But when I got in there with the feeler gauges sure enough it had.

Thanks for your support guys. It helped me see the light :thumbsup:


All the best.
Neo
 

Scrubcadet10

Lawn Addict
Messages
1,272
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

Well-Known Member
Messages
728
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

Well-Known Member
Messages
125
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

Well-Known Member
Messages
728
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

Lawn Royalty
Messages
12,837
Check the head bolts have not come loose
Also measure the height of the valve guide
They are also notorious for shifting.
 

bertsmobile1

Lawn Royalty
Messages
12,837
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
 
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