1996 Johnson Fast Strike 150

[sikes550]

I have some problems with my motor and need/request for help.

1996 Johnson Fast Strike
Model # J150ELEDB
Serial# G04078037

Recently, I launched the boat and the motor ran fine. Mid-day, I idled out of a slough and gave it gas to get on plane but the motor stalled and died. could get it to idle but it was rough. I kept trying to get it cranked but when I engaged the gear, the motor died. I had to be towed back to the ramp. I tried to crank it again there but it would not crank. A day or so later, I removed the plugs, sprayed some yamaha fogger in each cylinder, and replaced the Champion plugs with NGKs. It cranked and ran fine with the flushers attached to a garden hose.

A few days after that, I topped the fuel tank off with fresh gas, some yamaha ring free and fuel conditioner. I took it back to the lake and, again, it ran great for 45 minutes or so. I returned back to the launch (in case it would not crank again so I would not have far to go to get it back on the trailer), turned off the ignition, and cranked it up again and blasted off. I did this several times and everything appeared to be working fine. Having some confidence, I headed to a local marina and topped it off with gas again to make sure I had enough to make a long run up the lake and back. AFter fueling, I idled back to the main lake body past the marker buoys and gave it the throttle. The motor stalled and died just like it had done a few weeks ago. I returned to the ramp under power of the trolling motor and trailered home.

Today, I attached the flushers and garden hose and it would not stay cranked. I pulled the spark plugs and sprayed each cylinder with fogger. I put the same NGK plugs back in and it cranked fine. I engaged the gear and ran it for about 5 minutes with no problems. I am concerned that if I get it back to the lake, it will run great for 45 minutes and then refuse to crank after I sit and fish for a while.

Some folks I have talked to suggest it is a weak or failing power pack. Others suggest that the oil mix is too high or rich. In any event, it seems odd to have it running great one minute and then have it refuse to run the next.

Any thoughts from (1) the experts or (2) those who have had similar experiences would be greatly appreciated.

[Lockjaw]

Is it losing spark on one side, like the port?

If so, you probably have a power pack going bad. Mine would do the same thing, run for a while, then lose power. Got to scoping it out and it was only running on one side.

See if you can duplicate the problem and see if its losing spark. You don't need to keep spraying all that oil in it.

Also the guru's will fuss at your for using Ngk's. There is an NGK you can use, according to NGK, but it is a Z series plug and pretty pricey. Champions are alot cheaper and the recommended plug.

[fastman151]

Dave....first off...Welcome to the BBC!!!!!

Try this post and see if there is anything that might help you out. Pay special attention to the picture ( by Elgin) of the adjustment to the timing arm and throttle arm.

http://www.bbcboards.net...80062

[fastman151]

Hey Craig.....how's the Jav running? Did you ever get those 91 heads on, and if so, what was the results??

[Lockjaw]

Its running ok. Haven't gotten the heads on, but don't expect much of a change. I tried to put one on, but had issues getting the stupid thermostat gasket in, so I didn't get a seal on the top cylincer. Didn't see on the other 2 where compression was different.

Probably going to plug the idle reliefs when I do the head swap, so I don't think I will be able to say to well what the difference is going to be.

The heads looks the same to my eye though.

[javelinjay]

Lockjaw! Just wondering if you replaced your powerpack with a CDI or OEM. And if it was a CDI, did you use the stock wires or the blue CDI plug wires and reccomended plugs.

Thanks

Jay

[Lockjaw]

I went with an OEM one. The old parts guy in town told me not to run anything but OEM packs on an OMC.

My wires are Jacobs Energy low resistance 8mm that I made myself. I was hoping they would allow me to gap the plugs a little wider, but I haven't explored that yet.

Now if CDI could move the limiter, then I might go that route.