IFish.net banner

1 - 5 of 5 Posts

·
Registered
Joined
·
536 Posts
Discussion Starter #1
Went from the coast to cental oregon, new 50hp Honda is stalling out on the high lakes, but the kicker has no issues. If I have the engine adjusted for altitude here, will I need to adjust later at the coast or will it just run at a higher idle? When it runs, it runs, but at low idle or nuetral it cuts out. Typical issue?
 

·
Registered
Joined
·
424 Posts
I'm not a mechanic but i have been told that if you rejet it(it needs more than jsut screw turning adjustment) for altitude you need to rejet it back when you come down to sea level because you will be running too lean or too rich depending on which way it is rejetted for which atltitude you are at if you leave it the same for both.. I do know this though. Your motor however should not cut out or die even with it unaltered. I have a 2002 90HP Honda on a 17' Sylvan. i cannot get on a plane at Paulina with 3 larger people in the boat unless they are at the front. i also have a 2002 9.9HP Honda on the back. Both motors run fine at paulina which is 6380 feet. They start, idle, and run fine clear up to the highest RPM which they can achieve. There is no cut out, dying, or hesitation, or hard start with either one up there or down here. They just won't get near the rpm and of course the speed they will down heere. And it is dramatically less. My recommendation would be to go talk to the dealer or a honda authorized repair person.
 

·
Registered
Joined
·
29 Posts
Your engine is having a problem with getting enough fuel. The main engine should run just fine at that altitude. The kicker motor running fine is a good clue about what your main motor is having a problem.

Call the dealer that sold the engine to you and have them check it out. If you have any external fuel filters, you should check them out and replace if needed.

If you don't have external filters, think about installing one in a location that is easy to get to and service. This is your first line of defense for keeping your engine running with clean fuel. Boat fuel tanks are notorious for collecting all kinds of stuff that gets sent to the engine along with the fuel.
 

·
Registered
Joined
·
441 Posts
I'm not a mechanic but i have been told that if you rejet it(it needs more than jsut screw turning adjustment) for altitude you need to rejet it back when you come down to sea level because you will be running too lean or too rich depending on which way it is rejetted for which atltitude you are at if you leave it the same for both.. I do know this though. Your motor however should not cut out or die even with it unaltered. I have a 2002 90HP Honda on a 17' Sylvan. i cannot get on a plane at Paulina with 3 larger people in the boat unless they are at the front. i also have a 2002 9.9HP Honda on the back. Both motors run fine at paulina which is 6380 feet. They start, idle, and run fine clear up to the highest RPM which they can achieve. There is no cut out, dying, or hesitation, or hard start with either one up there or down here. They just won't get near the rpm and of course the speed they will down heere. And it is dramatically less. My recommendation would be to go talk to the dealer or a honda authorized repair person.
90 hp hondas are fuel injected 50 hondas are still carbed, injection has not issues with high or low altitude as they are compensated for by the processor, carbs have no processor thus are still vulnerable to altitude sickness!!:bearhug:
 

·
Registered
Joined
·
9,914 Posts
If it is carbed it will run richer in thinner air at altitude. You can rejet it,bbut then it will run lean at sea level, not a huge problem for 4 strokes but it will seize up a 2 stroke at low altitude with high altitude jets.

The carb set for sea level sees x cubic feet of air go into the engine and puts in y gallons of gas. At high altitude the air has less weight, so less oxygen so it put in too much gas.

Also less pounds of air goes through the engine per revolution so the power output will decline, even if tuned for the altitude.

When you are on the high lakes a prop with less pitch and an idle speed adjustment might get you by.
 
1 - 5 of 5 Posts
Top