New Intek twin runs on one cylinder

[2000J25SP]

I bought a brand new Briggs Intek twin 656cc 20hp. Swapped it onto my 1987 John Deere SX95 rear engine. Finally cranked it up today, and it runs rough and has no power. If I unplug one cylinder it makes no difference whatsoever. Swapped the spark plugs from one cylinder the the other and no difference. I guess I'll do a compression test tomorrow and go from there. Anyone have this problem before? Hopefully I'm overlooking something simple. Thanks

 

[bertsmobile1]

Remove both of the kill wires on the coils and see if that makes any difference
'

 

[2000J25SP]

Remove both of the kill wires on the coils and see if that makes any difference
'

I removed the kill wire going to the switch with no change. I can pull the top cover off tomorrow and try that. I suppose they could be grounded out on something.

 

[bertsmobile1]

The till wire between the coils has a pair of diodes in it to prevent the coils interfearing with each other .
Common problem, I do about 10 of them a year .
If I have read what you have posted properly it runs on either cylinder but not on both .

 

[2000J25SP]

The till wire between the coils has a pair of diodes in it to prevent the coils interfearing with each other .
Common problem, I do about 10 of
If I have read what you have posted properly it runs on either cylinder but not on both .

O

The till wire between the coils has a pair of diodes in it to prevent the coils interfearing with each other .
Common problem, I do about 10 of them a year .
If I have read what you have posted properly it runs on either cylinder but not on both .

Good to know, thank you I appreciate your help. Sorry I wasn't more clear, the rear cylinder fires, the front cylinder has never fired.

 

[bertsmobile1]

OK.
That is a different story
Remove the rocker cover on the dead cylinder
Chances are the pushrod has fallen off so one of the valves is not working.
IF it is a newer engine, buy a pair of rocker cover gaskets and put one in after cleaning all of the silicon off ,

 

[boatmoter]

I bought a brand new Briggs Intek twin 656cc 20hp. Swapped it onto my 1987 John Deere SX95 rear engine. Finally cranked it up today, and it runs rough and has no power. If I unplug one cylinder it makes no difference whatsoever. Swapped the spark plugs from one cylinder the the other and no difference. I guess I'll do a compression test tomorrow and go from there. Anyone have this problem before? Hopefully I'm overlooking something simple. Thanks

hook a volt meter or test light to the + & - of the coil not firing, run engine or just crank over,does it have a reading? if not,turn key on & check the + terminal on the coil to see if it has voltage

 

[bertsmobile1]

Ignore the post from Boatmotor
it is for a Kettering ( battery ) ignition , not a magneto ignition

 

[StarTech]

If the engine is truely brand new you are working on voiding the warranty.

 

[boatmoter]

Ignore the post from Boatmotor
it is for a Kettering ( battery ) ignition , not a magneto ignition

magneto ignition??? ever heard of a ignition system that's is fired by the ignition control module? power to the coil from ignition and the ignition control module grounds the coil to fire at the proper time