[Forest_walker]

Hello!

I have 60hp 2 stroke 3 cylinder 1990 mariner engine.

The problem is that it lacs power when driving it on water -even on small load (2 pers). Few years ago there was a similar problem and the reason was in the reeds sharing the fuel on the pistons.

We checked the reeds and there were small bits off from the tips of the reeds. So we changed all 8. (3-4 were broken.)

We almost celebrated our victory and set sails on the lake nearby but the powerloss still occured.

It runs nicely on water hose, takes full revolution. But when driving on it, the surfacing is uneasy and seems so that the engine lacks 60% of power in low revolution and 40% on high revolution. -So no hopes for wakeboarding.

Several professionals have cheked the engine. Others say that the flaw is in the ignition, but we explored that and changed the switch box and trying to explore the fueling system (switch box was from a used mercury).

We have the mercury mariner service manual (for models 45&50 (4 cyl), 50 (3 cyl), 60 (3 cyl) and 70 (3 cyl))

I have loads of dissassembly photos, and videos on the engine behaviour which I can send if necessary.

Thanks for reading this post!
Respect highly any help.

[Forest_walker]

Hi!

The case is solved. After sevreal testing and fixing the flaw was in spark plug cables and in the reeds changed mainly

Other parts given maintenance:

In one piston had broken rings so they were changed.

One carburetor had some dirt on it, when cleaned showed 20% increase in speed still laced power on acceleration.

We got a hint to test the switch box spraying the cool spray on it, so if there is some tiny fractures the hull of the switchbox will compress and the fractures become intact and the switch box will operate normally. When trying to do this while testing the boat on lake I felt a electric shock while touching the case of the engine. It was a rainy weather but there shouldn`t be any electric leaks on the hull.

When checking the spark plug cables one of them had fracture on it so that there was electric leak on a nut to the hull of the engine. Now when changing cables so that the broken one was not able to touch the nut in the hull engine worked perfectly. 65 km/h