72 mercury 1150

[jason1150]

took the boat out this weekend, did pretty good except it still wouldn't go over 30 mph, tried different trim settings, I did a link and sinc, I thought everything looked good, I'm running a 13" 17p 3 bladed prop, I don't have a tach so I couldn't tell you what the rpms are, it just doesn't seem to want to get on top of the water and plane, compression is pretty even on all 6, it's a 16 ft ski boat, not sure of the weight, I'm gonna work on it some more next weekend, was just hoping someone could send me in the right direction, thanks, Jason

 

[emckelvy]

Re: 72 mercury 1150

Jason, that motor on a light ski boat should rip in the mid 40's or better.

I don't expect that you're hitting on all cylinders. Most likely either a spark issue, or fuel problems.

You can do a few checks at home on the flusher; clamp an inductive timing lite around each plug and see if it's firing in the cylinder.

Also, choke off each carb throat with your hand, it'll either speed up, die out, or do nothing. If it speeds up you have fuel problems. If it does nothing those cyl's aren't working at all, for whatever reason.

You can also try spraying some fuel/oil mix into each carb throat and see what that does for you.

Anyway, having even compression is a good sign, now you need to narrow down the problem.

HTH & keep us posted...........ed

 

[jason1150]

Re: 72 mercury 1150

thanks ed, will try those things and see what's really going on, didn't really think about it since it seemed to run so good, Jason

 

[fch2cxr]

spark but not firing.....

spark but not firing.....

"Also, choke off each carb throat with your hand, it'll either speed up, die out, or do nothing. If it speeds up you have fuel problems. If it does nothing those cyl's aren't working at all, for whatever reason."

EMCKELVY...if spark is present.. and compression is good... what might be the problem??

 

[jason1150]

Re: 72 mercury 1150

I tested the spark on all cylinders when I got it and they all were good, maybe fuel filters are clogged?

 

[Plainsman]

Re: 72 mercury 1150

I tested the spark on all cylinders when I got it and they all were good, maybe fuel filters are clogged?

That doesn't mean that the spark is still good, I'd recheck it

 

[jason1150]

Re: 72 mercury 1150

what's the best way to check the spark, I took each plug off and had a buddy crank it while I held it close to ground, I'm kinda suspecting that the cap and wires need to be replaced, it has a bit of a rough idle and they look original. Also I found one of the fuel filter caps leaking so I tightened those bolts down, guess it came loose after I rebuilt the carbs, thanks, Jason

 

[timmathis]

Re: 72 mercury 1150

You may wan't to give the timing a check also. Tim

 

[Plainsman]

Re: 72 mercury 1150

what's the best way to check the spark, I took each plug off and had a buddy crank it while I held it close to ground, I'm kinda suspecting that the cap and wires need to be replaced, it has a bit of a rough idle and they look original. Also I found one of the fuel filter caps leaking so I tightened those bolts down, guess it came loose after I rebuilt the carbs, thanks, Jason

Get a inline spark tester. The one that has the dial

Take the cap off and clean the inside with hot soapy water and a brush. I use an old tooth brush for it.

 

[jason1150]

Re: 72 mercury 1150

does that spark tester tell how strong the spark is or just that it has spark

 

[Plainsman]

Re: 72 mercury 1150

I should be a bright blue spark