# Briggs and Stratton Vanguard 18hp V Twin OHV Dead Cylinder



## Chaw0225 (Jun 20, 2012)

So 2 Briggs and Stratton mechanics at 2 different locations are stummped and I am still stuck with a motor that doesn't work the engine model is 356447 with a type code of 0079-e1. One mechanic did a leak down in front of us and it was good on both sides, spark is good on both sides both sets of valves have been set. Every test that should be done has been. When running we grounded out one of the plugs and the engine died, tried the same thing on the other and engine runs on one cylinder. What would cause this? Please help!


----------



## Basementgeek (Feb 7, 2005)

Hi and welcome to TSF

Your post is kind of confusing. They both run OK-correct? The problem is shutting them down?

How are you grounding them out?

BG


----------



## Chaw0225 (Jun 20, 2012)

The engine runs, starts, and shuts down however one cylinder runs cold while the other runs hot/normal we were told to test the cylinders by starting the engine Letting it run at idle and grounding out one of the plugs, if the other cylinder continues to run the engine all is well, when we did this test one side allowed the engine to run on one cylinder the other did not. We believe one cylinders timing is off but at this point we are not sure what the problem is


----------



## Basementgeek (Feb 7, 2005)

Ignition is controlled by the wheel/flywheel key and crank.
It uses 2 coils, one for each cylinder. Yes grounding one plug wire would leave the 
one cylinder firing and maybe running.

Can't answer why one runs and one does not.

BG


----------



## Chaw0225 (Jun 20, 2012)

We pulled flywheel to make sure key was ok and all was fine do you know what would cause compression on one side of 50 and the other 90


----------



## MrChooks (Apr 19, 2008)

Any number of reasons that you get different compression test results but at @ 50 & 90 - both are well & truly capable of making the engine run - I doubt that compression is the issue.

As fuel / air is delivered by a common manifold - If one cylinder works - the other should also.

So we are now down to ignition. If the keyway is good and one cylinder works fine but the other doesn't and given BG's comment that the engine has 2 independent ignition coils - The cylinder that runs cold has a suspect coil, irrespective of the fact that it will fire a plug outside of the cylinder. The load on the ignition system is much higher / different when the plug has to fire on compression in the cylinder.

A new coil / ignition is only about $60 to buy and attaches with 2 screws - If it were my engine - I would spring for a new coil and see what happens - better than even money bet that that will fix it - after all @ $ 60 - it works out at about 45 minutes of B&S tech charge


----------



## Chaw0225 (Jun 20, 2012)

Both plugs were tested while in the enigine using the cable that attaches to the top of the plug and plugged into the spark plug wire and has a light bulb in the middle to visually show that it is firing both sides were tested at the same time and had the same appearance in firing


----------



## Basementgeek (Feb 7, 2005)

Since you two engines thus four coils have you tried to swapping coils?

BG


----------



## Chaw0225 (Jun 20, 2012)

I should have thought of that because that will determine if the coil is bad! I'll give it a try and let you know


----------



## MrChooks (Apr 19, 2008)

When you do the "swap test" - make sure you swap the spark plug as well - you want to test the entire igniton system.

If you find the coil defective - I think the B&S part No. is 844548 and if you Google "ARMATURE-MAGNETO 844548" you will get any number of on line parts suppliers in the US with prices bewteen $US35>$US40


----------

