nickcheras
Recruit
- Joined
- Jun 8, 2008
- Messages
- 1
Hi,
I've got the above mercury engine with roughly 120hrs use since new and am having the following problem with it..
The engine starts and idles perfectly smoothly, (just serviced) shifts nicely from neutral to forward and to reverse. Once the throttle is opened (i have checked that the butterflies open fully) the engine revs to 2900 rpm quickly but bogs there and sounds very flat, i also notice a slight knock but if i am honest i think it has always been there since new, and it basically refuses to engage the other 2 cylinders and hit the power band (i am aware of the 2+2 config - but would love to know which two cylinders are used to idle and which kick in later, because i am pretty sure that it is the top two that idle - but is that possible on an inline 4 engine?. ) the boat (21" Bayliner Trophy) last year would hit 5300rpm easily and hit speeds of 32 - 35 knots. I've had the engine removed and stator changed, a full service performed, plugs, fuel pump all replaced, carbs dissasembled and cleaned / adjusted and compression measured (125psi roughly on all cylinders)- all professionally done, but now my mechanics are all scratching their heads and cannot find the problem. I am starting to worry that i have a bigger problem with the engine and maybe need to think about reconditioning it, but would like to hear some expert opinion since i am based in Greece, and expert mechanical opinion on these particular engines is hard to come by!!!
Thanks in advance for any ideas
Nick
I've got the above mercury engine with roughly 120hrs use since new and am having the following problem with it..
The engine starts and idles perfectly smoothly, (just serviced) shifts nicely from neutral to forward and to reverse. Once the throttle is opened (i have checked that the butterflies open fully) the engine revs to 2900 rpm quickly but bogs there and sounds very flat, i also notice a slight knock but if i am honest i think it has always been there since new, and it basically refuses to engage the other 2 cylinders and hit the power band (i am aware of the 2+2 config - but would love to know which two cylinders are used to idle and which kick in later, because i am pretty sure that it is the top two that idle - but is that possible on an inline 4 engine?. ) the boat (21" Bayliner Trophy) last year would hit 5300rpm easily and hit speeds of 32 - 35 knots. I've had the engine removed and stator changed, a full service performed, plugs, fuel pump all replaced, carbs dissasembled and cleaned / adjusted and compression measured (125psi roughly on all cylinders)- all professionally done, but now my mechanics are all scratching their heads and cannot find the problem. I am starting to worry that i have a bigger problem with the engine and maybe need to think about reconditioning it, but would like to hear some expert opinion since i am based in Greece, and expert mechanical opinion on these particular engines is hard to come by!!!
Thanks in advance for any ideas
Nick