Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

[searay1999]

Suddenly my Boat is running sluggish, idles poorly and has no power.(No way pulling a skiier out of the water) The highest rpm i can get is 3200rpm. Normal is about 4600rpms. At cruising it seems to want to hestitate. This problem seemed to happen overnite. someone suggested bad fuel but I drained and put new in. Still have the same problem. This is a Searay with a 3.0L Mercruiser with 120hours on it. Any suggestions would be very appreciated.

 

[damie]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

sounds like fuel problem poss fuel starvation because of blocked fuel filters there is a strainer in fuel inlet union on this carb(mercarb2bl)or at worst clogged or corroded fuel bowl in carb floatchamber(as mine had).<br />i fitted a new carb in this case as i didnt want<br />corrosion to continue to block jets(go2marine.com)<br />or could be weak fuel pump(mechanical on this model)i converted to electric pump to overcome this,but i believe regs are different over the pond!!.

 

[The Marine Doctor]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

As always..start with the basics...compression and spark.<br /><br />TMD

 

[johnkc]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

assuming you have the original a c spark plugs mr43lts trash them as that is what they are, and install ngk bpr6efs.and i think there is a revision to the timing spec to t.d.c.

 

[jimmmy]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

I have a similar problem on an 1989 3 L merc I purchased 7 weeks ago. I can't get over 2600 RPM under load. It will turn 4500RPM in neutral. But in gear....forget it. Carb has been rebuilt twice, filters changed, head machined (due to cracked head gasket), new points, plugs, condensor, prop changed to 17 pitch...(I could go on!), and still no difference.

 

[searay1999]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

Thanks for the feedback so far. This happened suddenly (like overnite). I used to be able to get it upto 4600rpms, 45mph trimmed, 21 Pitch Prop. I ended up taking it to the shop and see what happens...I will post the results.<br /><br />Thanks again<br /><br />Frank

 

[jimmmy]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

Please let me know what they find out. I've had my boat a two different shops over the past 7 weeks for a cost of $1600 and nobody has fixed the problem yet!

 

[searay1999]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

Yes will be glad to let you know! My boat is still under warranty! I am hoping its a warranty fix. It better be!!!!

 

[searay1999]

Re: Mercruiser 3.0L Sudden power loss can't get over 3200 RPM

Update: Faulty Plugs and timing...I have not tested the boat yet. They claim its fixed.<br />The reported number 2 cylinder is lower than the other 3. 170 compared to 190 on the others.<br /><br />I hope there is not a new problem here.<br /><br />Thanks Everyone!