150gt boggs

[shawn1]

I have a Johnson 150 gt,i think around late 80's.Engine starts great and runs well but boggs when its cold for about a minute.At about three thousand it just runs and spits abit untill it warms up then it kicks in and runs excellent. Will not run over three thousand till it warms up.Is this normal or whats the problem?

 

[Joe Reeves]

Re: 150gt boggs

No, that's not normal.

When engine is cold...... Check the compression. What are the readings of each cylinder?

With s/plugs removed, check the spark which should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it? If not, what kind of spark are you getting?

Spark plugs should be Champion QL77JC4 plugs, gapped at either .030 or .040 (One setting or the other may improve performance).

 

[shawn1]

Re: 150gt boggs

Thank you for the reply. The model number on the engine is J150stlcoh and the serial number is j6132314.I am not sure what year it is but maybe you can help me out.Also the plugs are ngk BUHXW-1. Its a strange plug because it has no gaps,just a electrod that sticks out.You think the plugs not warming up and that why it take so long to run properly?

 

[Joe Reeves]

Re: 150gt boggs

Model J150stlcoh indicates that your engine is a 1985 150hp model Johnson.

The plugs you're describing and using are "Surface Gap" Japanese plugs which I, and many others, do not care for. This type spark plug, regardless of the manufacturer, are cold running plugs and tend to foul easily.

Use the spark plugs I recommended as per my previous reply.

 

[emdsapmgr]

Re: 150gt boggs

Have you recently had the carb apart for cleaning and inspection?