Fishing Report Mercruiser Help/Grand River Walleye May 25

[Bassboy19]

Hi Guys,

Wondering if anyone can help me out, my '99 Mercruiser 3.0 Alpha has been giving me hell since I brought it out of winter storage, ran it 2 weeks ago and then the other night again and same result. Soft to moderate knocking at low idle, and is giving me about 3/4 speed and rpm from what I recall running it last year. Google thinks it might be crappy gas for the knocking, which makes sense since I had half a tank of stablized gas in there and then topped it off about 8 weeks ago in early April when I took it out. Going to empty the tank and try again, I always run 100% premium but I've read it's not that simple, some ethanol in some premium fuels as well?

Anyone have any insight? Engine starts fine but knocking at idle, and runs fine at mid range. Upper end is giving me 3500rpm and 30 mph max, used to get 4500+ and 38-40mph. No other variables I can think of, ran like a dream last summer. First time stern-drive owner, not sure where to start besides the gas and maybe some seafoam.

On another note, got into the wallys in Dunnville on the lower grand the other night. 9-12 fow trolling green/gold wally divers/wally minnows. Lots of sheep and a couple cats, beauty night to be out there. Good eater size, should have ran braid though, tough to feel bottom and bites with the mono. Best results running them just ticking off bottom.

 

[Fishfarmer]

I have had these engine symptoms with timing issues, bad bushing in distributor body.
80s merc 165

 

[Richardscott999]

Shell V Power hi octane with no ethanol. That’s all I run. Is about same price for premium as you pay in marinas for regular.

Rick

 

[tazmania]

Lifter that possibly lost its prime or sticking? Stuck one might have lightly bent push rod?
Some lucas oil treatment to see if that helps or check rockers for any play?

 

[maytagman]

What is your oil pressure when warmed up?

 

[Red Hering]

Hi Guys,

Wondering if anyone can help me out, my '99 Mercruiser 3.0 Alpha has been giving me hell since I brought it out of winter storage, ran it 2 weeks ago and then the other night again and same result. Soft to moderate knocking at low idle, and is giving me about 3/4 speed and rpm from what I recall running it last year. Google thinks it might be crappy gas for the knocking, which makes sense since I had half a tank of stablized gas in there and then topped it off about 8 weeks ago in early April when I took it out. Going to empty the tank and try again, I always run 100% premium but I've read it's not that simple, some ethanol in some premium fuels as well?

Anyone have any insight? Engine starts fine but knocking at idle, and runs fine at mid range. Upper end is giving me 3500rpm and 30 mph max, used to get 4500+ and 38-40mph. No other variables I can think of, ran like a dream last summer. First time stern-drive owner, not sure where to start besides the gas and maybe some seafoam.

On another note, got into the wallys in Dunnville on the lower grand the other night. 9-12 fow trolling green/gold wally divers/wally minnows. Lots of sheep and a couple cats, beauty night to be out there. Good eater size, should have ran braid though, tough to feel bottom and bites with the mono. Best results running them just ticking off bottom.

Nice walleye & Congratulations @Bassboy19

 

[Rylann]

How much fuel have you ran through it? Is there any old fuel left? I am wondering if you have some crap in the carb. I can't guess on the knocking. How many hours on the motor? Is it a top end knock or a bottom end knock? I am with may maytagman, what is your oil pressure?

 

[Bassboy19]

Thanks guys, oil pressure was running normal, around +/- 40psi. There is about 1/3 tank of old old fuel in there, come to think of it I filled it up last mid-August and ran it down to about half before winterizing first week of November. That gas sat in there for around 3 months untreated, then stabilized over winter. Then I gave it another half tank of fresh gas on about April 3. It ran pretty good the first time I had it out, then 6-8 weeks later it is running rough. I am going to run a bottle of seafoam through it to almost empty, top it up with fresh premium (thanks for the Shell V-Power tip too!), and see how it comes back. The engine has around 650 hours, the gentleman I bought it from last had it tuned up in 2018 based on the receipts I saw. The knocking is at the bottom end at idle, nothing noticeable at top end, but not getting power.

I called up James at Marine One in Ancaster, great guy to deal with, he seems to think the carb needs servicing. Sad news, he is moving his business to Florida for 10 months of the year and will only be doing business at his Ancaster location in July and August. I have had great dealings with him and will be looking for a new mechanic in Hamilton area if anyone has any suggestions.