Johnson GT 150 not getting up to speed.

[v12mac]

Re: Johnson GT 150 not getting up to speed.

This may be out of left field but here are 2 ideas.<br /><br />Could the spark be getting weak at WOT? If you have tried everything why not try isolating the ignition / key switch? (This is my new solution to everything) <br /><br />Could you have water trapped in the hull somewhere? This could cause the steering problem and cause you to scrub lots of speed, especially if you are running a step or pad V style hull.<br /><br /><br />Mac

 

[silverwing_6]

Re: Johnson GT 150 not getting up to speed.

Thanks for the ideas.<br /><br />I have tripple checked any connections and work I did as well as had 2 other small engine mecanics check behind me.<br /><br />I did not take off or adjust the floater.<br /><br />I don't know about leaking needle valves, just that all the valves,lines, and orphices are free of gunk.<br /><br />I took the carbs appart again to make shure and yes I did properly install all the gasgets and O-rings.<br /><br />For the passed year and a half I have been using the same oil and, on averag, the same amount of oil to gas and I have never had a stuborn problem like this.<br /><br />It's getting a very strong spark.<br /><br />I installed three bilge pumps, one infront, one inthe middle, and one inthe rear of the boat.<br />I did this because I like to go in the intercoastal waterway and the inlets so it gets a little rough.

 

[silverwing_6]

Re: Johnson GT 150 not getting up to speed.

Would the lower unit have anything to do with it?<br />I mean after repeated uses around larg 40' underwater trees, lake marion, could the fin on the lower unit just got bent a little to much.<br />Remember the tab was bolted in place 2 years ago and has not been ajusted.<br />If you are looking from behind the boat, the lower unit fin is bent to the left about 15 degrees.

 

[silverwing_6]

Re: Johnson GT 150 not getting up to speed.

If this could cause the problem which way should I turn the tad after unbolting and drilling new holes?

 

[silverwing_6]

Re: Johnson GT 150 not getting up to speed.

Do you guys think I need new floaters and needles for the carbs?

 

[silverwing_6]

Re: Johnson GT 150 not getting up to speed.

hey guys I'm signing off.<br /><br />If anyone has an idea please let me know.<br /><br />silverwing_6@excite.com

 

[madbanchee]

Re: Johnson GT 150 not getting up to speed.

Just curious... what is the pitch on your prop and what is the gear ratio on that motor?<br /><br />Oh yes, one more thing... is this motor rated 150hp at 5000 rpm and are you achieving it?

 

[silverwing_6]

Re: Johnson GT 150 not getting up to speed.

I don't know and my rpm gage does't work.<br /><br />how can I find out?