1987 Johnson 40VRO

[jsf1pilot2b]

After a few hours of problem free boating on the lake the fuel line on my Johnson 40VRO came loose from the motor and it shutdown. After a few minutes I was able to figure out the problem. After reconnecting the line and restarting the motor, it had only half its original power. On my way back to the launch it started firing on both cylinders again and ran great. I felt relieved. The next time I started the motor it had only half its power again. I have narrowed it down to the top cylinder not firing. I replaced both plugs with Champion Marine plugs. No change.
I swapped the coils and the problem is still in the top cylinder. I think that eliminates it being a coil. I can only achieve 1700 RPM at best.
What could possibly have caused this and how can I fix it????
Please help.

[tashasdaddy]

check your compression on both, here's some test for the powerpack:
http://www.boatpartstore.com/page32.asp

[Kevin W]

Its very likely you have two separate problems .
When your fuel line fell off the VRO will keep pumping oil even though there was not any gas to mix with it. This could foul the plugs or cause the short term power loss.
The second occurance is most likely not related.
I would test the power pack like mentioned earlier.

[jsf1pilot2b]

The VRO has been disconnected by the previous owner so the fuel/ oil mixture is done manually. Also the power pak looks to be fairly new. I would guess it's less than two years old. Do these Power paks fail often ??
If so are they expensive to replace??

[rickdb1boat]

Worth a try. They are only $58.12 here at iboats...

http://www.iboats.com/mall/partfinde...****=900714493

[jsf1pilot2b]

Thanks guys for all the help. I have printed a lot of troubleshooting info. and I will begin the task of finding the problem on my next day off from work. Can anyone tell me what would make these Power Packs go bad??? The Power Pack that it has looks like new.
Thanks.

[rickdb1boat]

Like any other electronic device, they can fail at any time. Heat and high voltage are usually the major contributors...