6hp motor dies after 1.5 hours

[olson101]

I have a Johnson 6hp motor model 6BJ6RL CEC. It dies after aprox. 1.5 hour.
It restart but at full speed it die. After 3-4 hours the motor run well for 1.5 hour.
On 1 ignition coils I can see a crack. Step to solve the problem?

 

[floatingwoody2006]

Re: 6hp motor dies after 1.5 hours

I think you've solved your issue.. Replace that coil. You will need a puller to get to it. Get the type that screws in with 3 hardened bolts. I would clean the points by putting a business card inbetween them and pulling it out a few times and maybe replace the plug wires while i was in there also. SOmeone will be along any minute to tell you what year it is. Im sure the coils will not be difficult to find.

 

[olson101]

Re: 6hp motor dies after 1.5 hours

I try to replace the coil.
I need some information:
idle rpm
max rpm
cilinder compression
max driveshaft torque (grear friction)

 

[Vic.S]

Re: 6hp motor dies after 1.5 hours

That is a 1989 model. It has electronic ignition so there are no points. There are two coils, one for each cylinder, which are not under the flywheel so no need for a puller. They are clearly visible and accessible bolted on the side of the engine

BUT if the engine dies completely it is not likely to be due to the cracked coil as it would continue one one cylinder. (It should be replaced though)

Check for sparks at each plug after it dies. If there is no spark from either it is more likely that the power pack is at fault (or both coils faulty)

Also check that the fuel tank vent is open properly.

the parts diagrams at http://epc.brp.com/default.aspx?brands=ej&lang=e may be useful.


Maximum power is 4.5 kW (6 hp ) at 5000 rpm

 

[floatingwoody2006]

Re: 6hp motor dies after 1.5 hours

Man.. I hate shooting myself in the foot. all 4 of the johnsons i have worked on have been vintage enough to have points set up. Ill keep to the asking side of the advice until i break my newer one, and know better. Mmmm Humble pie..

 

[iwombat]

Re: 6hp motor dies after 1.5 hours

1.5 hours until it dies? Sure sounds like a tank venting problem to me.

 

[Vic.S]

Re: 6hp motor dies after 1.5 hours

1.5 hours until it dies? Sure sounds like a tank venting problem to me.

That's why I suggested checking the tank vent but would it run for 1? hours. Depends on the throttle opening and how full the tank is I guess.

 

[iwombat]

Re: 6hp motor dies after 1.5 hours

At WOT that 6hp would pull roughly .9 gal of gas in 1.5 hours. In a 6gal can, that's probably about the right amount of vacuum to overcome the fuel pump.