re-jetting carbs for altitude

[bassnmamma]

Pardon my ignorance, but if I re-jet my carbs for high altitude (5-6000' above sea level), do I just re-jet the main jet? This is for a '90 Evin 150XP. I moved from sea level to mile high, and do not anticipate operating the boat at any lake below 5,000'.

 

[walleyehed]

Re: re-jetting carbs for altitude

OMC/Bombardiar does not recomend changing jets any more because of fuel quality. Although I still go 1 or 2 steps at 3600ft., with the 90deg crossflow engines and have had excellent results.

 

[bassnmamma]

Re: re-jetting carbs for altitude

Being a female (who happened to tour for several years in the pro women's bass circuits), I'm having a difficult time finding an outboard mechanic I can trust. I'll keep working on getting my setup right, but am having a very hard time adjusting to the loss of hp up here! I have a need for speed!!! Thanks for your help regarding my posts.

 

[walleyehed]

Re: re-jetting carbs for altitude

Look up Best marine in Denver-they do great work and very professional people.<br />Good Luck!!!

 

[clanton]

Re: re-jetting carbs for altitude

There is service bulletin that has this information, but not sure what model years are covered. Find a dealer and ask them to look. Even with a jet change you may have to drop prop pitch. You may be able to change throttle pickup timing, to help it get on plane.

 

[bassnmamma]

Re: re-jetting carbs for altitude

Thanks for advice. The boat repair that replaced my VRO recommends a four thousandths drop in main jet. Am in the process of gathering baseline performance data before fiddling around with anything. Checked new plugs after running about 20 minutes and they are wet fouled. I didn't know I'd spend so much time re-doing set up on my boat for altitude. I mean, my car works fine up here... Don't know why darn boats have to be so finicky. As my hubby says, "Boats are holes in the water into which you pour money!"