'93 50hp 3 cyl Merc......sluggish out of the hole

Post by **Roughneck1860** » Sun Jul 04, 2010 6:29 pm

I have a 1993 3 cylinder 50hp Mercury. I have it on a Lowe Roughneck 1860VT mod-v jon boat. I'm running a 12" 4bld aluminum prop. Dry weight of the boat is around 650lbs. Lately the motor has been real sluggish coming out of the hole and up onto plane. I cleaned the plugs and it made a bit of difference but not much. I checked the compression and its about 107psi on all three cylinders. It used to jump right up on plane with no issues so I'm kind of wondering whats up. Top speed is about the same at 31.8 mph loaded. Anyone have any thoughts?

Thanks
Tim

Post by **Cyber** » Sun Jul 04, 2010 7:11 pm

Could it be the power-pack (aka c.i.d. box??

)

I had the same problem w/ a 3 cyl. 70 H.P. Merc.
a few years back and that's what it was.

Not cheap to fix either!

Post by **Roughneck1860** » Sun Jul 04, 2010 7:17 pm

I dont think so. I had a CDI box go before. This motor runs as smooth as it did before it just lacks the bottom end punch it always has had. The motor I had the CDI go on sputtered and ran alot worse than normal.

Thanks
Tim

Post by **moonshine** » Sun Jul 04, 2010 9:13 pm

before you look for something more serious i would try some seafoam and NEW plugs. hopefully its not getting tired already

Post by **Cyber** » Mon Jul 05, 2010 9:16 am

When my cdi box went, the motor would idle along fine, but
when you punched it, it would SLOWLY climb up to WOT and
then run fine as long as you wanted. Slow down again and it
would repeat the same pattern. Not so good for waterskiing!

Hopefully you get away w/ something cheaper, just relating my experience w/ 3 Cyl. Mercs.

Post by **Roughneck1860** » Mon Jul 05, 2010 4:57 pm

Thanks Cyber. I was just going by how my last Merc was when the CDI box went. I'm going to strip and clean the carbs as well as put in a new set of plugs and see how that does then go from there. If it doesnt get any better I will look at the CDI box. I found one for $100 if I need it. A buddy got it when he though that was the problem with his 60hp but it turned out to be something else and he never used it. He's since up graded to a 75hp 4 stroke and still has the part.

Thanks
Tim

Post by **Raminator** » Mon Jul 05, 2010 8:07 pm

i would check the simple stuff like a sticky needle or just rebuild the carbs