# [SOLVED] 5hp Briggs Stratton timing?



## brendan2013 (May 3, 2013)

Hi,

Old Briggs and Stratton engine on a ride on mower. It's been left outside over winter.

I put a magnetron coil to replace broken points coil, I have a spark but the nearest I get to ignition is an occasional blowback out of the carb during pull start attempts. 

I've cleaned the carb, inspected the valves (not sticking), checked flywheel key, the coil is mounted the right way up (plug lead at top, kill switch at bottom (kill switch not connected to anything). 

I've checked all the gaps at coil, spark plug and valves - all are pretty good. Tried several spark plugs. Tried several carb settings although mostly used choke on with brake cleaner to try and get ignition going - the carb is pooling a little fluid but the plug is only mildly wet.

The only things I can think of is the timing is off - is there any way I can eliminate this by, perhaps, opening the coil/flywheel gap? I'm sure cleaning the valves would help, but would they just stop ignition altogether?

After several attempts over a couple of days I've simply run out of things to check!

Any help appreciated,

thanks,
Brendan


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## Basementgeek (Feb 7, 2005)

*Re: 5hp Briggs Stratton timing?*

Hi and welcome to TSF

Timing is control by the flywheel position only. Flywheel position is control by the keyway. If the key is bent, even a little, or broken, ignition will be off.

Yes valve opening is very important to the engine running or not.

BG


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## brendan2013 (May 3, 2013)

*Re: 5hp Briggs Stratton timing?*

Thanks BG, 

Flywheel key is solid, there was a new one with the kit but I didn't see a reason to change it.

The valve gaps are good enough to get some sort of combustion... everything could do with a bit of TLC but there must be something more significant happening somewhere.

I thought I googled that an electronic ignition had slightly different timing to a points one (it's a 130902 engine)? 

I guess if there's no adjustment on timing needed then I'll just leave it overnight and check over it with a fresh mind tomorrow, and save cleaning the valve seating as a last resort.

Any pointers of things I can check would be appreciated..


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## brendan2013 (May 3, 2013)

*Re: 5hp Briggs Stratton timing?*

Problem solved - the key had sheared.

A new problem though - I put the spare key in, engine ran nicely for 30 seconds or so and then sheared the new key!

The condensor cover says 'do not put a steel key in' but I don't see much choice?

Is there likely to be a cause for sheared keys? Old oil or something like that...


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## SABL (Jul 4, 2008)

*Re: 5hp Briggs Stratton timing?*

Make sure the mating surfaces are clean and dry before installing the flywheel. You'll need to find the model number and torque the flywheel nut to specs.....I'm seeing 55 ft lbs as the minimum torque for any B&S flywheel. 

Torque Specifications for Briggs and Stratton


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## brendan2013 (May 3, 2013)

*Re: 5hp Briggs Stratton timing?*

Thanks Sabl - that must have been it, I'll try again tomorrow.


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## brendan2013 (May 3, 2013)

*Re: 5hp Briggs Stratton timing?*

Yes, all working once correctly torqued. Thanks for your help!


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## SABL (Jul 4, 2008)

Glad to hear you got it sorted......:thumb:

This type of problem had me stumped many, many years ago......it's an easy fix you never forget once it happens to you and you get it corrected.


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