1975 15hp Evenrude throttle adjust (high end)

[Seawolf_504]

Hey guys, This is my first post here and I apologize if this topic has been covered before, but I could not find anything specific in a forum search.

I have a 1975 15hp Evenrude outboard that had some start issues and I finally traced the issue down to a dirty carb. I got the carb out and cleaned just fine and the motor cranked up no problem and ran great.

I got the top needle valve (mixture control) adjusted where it idles and runs great, but once out on the water at full throttle it doesn't quite get up to full power. While at full power I can reach down and pull the choke out about an inch and a half and the motor will suddenly kick in at a higher RPM and get up on a nice plain.

Obviously I'm not getting all the power available with the twist throttle so how do I adjust it to get full range? Is it a high end needle adjustment or maybe the choke?

Thanks for your help.

 

[Rick.]

Re: 1975 15hp Evenrude throttle adjust (high end)

Sounds like you've made some good progress. I hate to say it but your high speed carb. pathways need more cleaning. Your going to have to clean that carb. one more time. You never said if you put a new kit in it. I would. Best of luck. Rick.

 

[Seawolf_504]

Re: 1975 15hp Evenrude throttle adjust (high end)

No I didn't put a new kit in it and I guess that should be the next step. The only thing I took off the carb was the float bowl cover and whatever metering screws I could find.
While I had the carb out I flushed it with carb cleaner and air to make sure nothing was blocked. The float was good to go and operated freely
I've never rebuilt a carb before so I'm a little nervous about doing it, but theres only one way to learn I guess.

I'll have to check the maint book when I get home, but I'm pretty sure this carb has a high speed adjustment as well, but it might be on the bottom of the carb and hard to get to.
Is the high speed needle something I need to adjust with the motor under a load at full power or is it something I can adjust at idle while on the hose at home?

Thanks

 

[bktheking]

Re: 1975 15hp Evenrude throttle adjust (high end)

There is no high speed adjustment on this carb, IDLE only. You will need to completely tear is down and soak it, do the plugs too. The kit will come with everything you need to make it work properly again, OMC kit that is- comes with the float, I highly recommend it.

 

[Seawolf_504]

Re: 1975 15hp Evenrude throttle adjust (high end)

Ok good deal, thanks for the info.

On Iboats they have two different kits available without floats. Sierra and Mallory. Does it matter which one? and should I replace the float as well? The float is in good shape right now.

 

[bktheking]

Re: 1975 15hp Evenrude throttle adjust (high end)

No idea, I only use OMC, try Sierra