I have the above motor - relatively new to me (purchased used last year with used boat). My current issue is the motor seems to be missing or I have an adjustment to make (this is probably obvious). The motor generally starts ok (3rd or 4th try) with choke and I usually have to run it above idle for a little bit to warm up or it will die. Once warm it seems to idle fine (though at times the idle seems fast in neutral but once in gear it's fine).
The issue is that it seems a bit rough in the low RPMs in general. I wasn't sure what to make of it and thought maybe this motor just runs a bit rough in the lower RPM's (I've never had a motor this big). Once I hit it, it takes off great and pulls right out of the hole and runs smooth with plenty of power. But this weekend was a bit windy and I needed more than just idle to toodle around, a bit more pep around 1/3rd throttle. What I found is that the motor appears to not run on all cylinders at low speed/idle but does at WOT. While I was trying to hold it at about 1/3 throttle there was a fine line where the motor would waffle between a bit rough but consistent (slow speed) and very smooth with a kick of power.
As the motor would kick in with the additional power the boat would lunge forward in response and I'd have to back off the throtte. It's almost as if it's running on 2 cylinders at low RPM and all 4 at higher RPM but the transition, when done slowly, is not smooth. It's very clear when they all hit.
Does this sound like a cylinder thing, a carb thing or something else? I tried adjusting the carbs last year with new plugs. The sticky on "how to adjust carbs" is almost identical to my engine manual and I thought I did it right but maybe I didn't. I'll admit I found it hard to adjust two carbs at once...or how to identify if the carb I'm working on is responsible for the lugging/overloading "sound" or if it's the one I'm not messing with...and vice versa. I did the adjustment in the lake so the motor was under load as suggested.
Any thoughts? It's new gas with proper oil ratio.
Thanks!
The issue is that it seems a bit rough in the low RPMs in general. I wasn't sure what to make of it and thought maybe this motor just runs a bit rough in the lower RPM's (I've never had a motor this big). Once I hit it, it takes off great and pulls right out of the hole and runs smooth with plenty of power. But this weekend was a bit windy and I needed more than just idle to toodle around, a bit more pep around 1/3rd throttle. What I found is that the motor appears to not run on all cylinders at low speed/idle but does at WOT. While I was trying to hold it at about 1/3 throttle there was a fine line where the motor would waffle between a bit rough but consistent (slow speed) and very smooth with a kick of power.
As the motor would kick in with the additional power the boat would lunge forward in response and I'd have to back off the throtte. It's almost as if it's running on 2 cylinders at low RPM and all 4 at higher RPM but the transition, when done slowly, is not smooth. It's very clear when they all hit.
Does this sound like a cylinder thing, a carb thing or something else? I tried adjusting the carbs last year with new plugs. The sticky on "how to adjust carbs" is almost identical to my engine manual and I thought I did it right but maybe I didn't. I'll admit I found it hard to adjust two carbs at once...or how to identify if the carb I'm working on is responsible for the lugging/overloading "sound" or if it's the one I'm not messing with...and vice versa. I did the adjustment in the lake so the motor was under load as suggested.
Any thoughts? It's new gas with proper oil ratio.
Thanks!