mercury 135 v-6 ,spark advance vs. power

[dutch135]

1988 Mercury v-6 135hp outboard on a SeaRay Seville. I had the boat in the shop last year for fuel pump problems, and I was told that the Spark Advance had been set ahead, so the shop set it back to factory spec. When i got the boat home, it ran ok, but had no power when compared to before. It would hardly pull a skiier, and top speed had dropped from the high 40's,, to barely cresting 40 mph. I reset that back to where it was, and got my performance back, but I am still curious if this is an indication of another problem. They had done a compression test, which was very good. I have had ignition work done in the past, and feel that with the fuel problem fixed it is running as good as it should. Any thoughts would be appreciated!

 

[dutch135]

Re: mercury 135 v-6 ,spark advance vs. power

some other notes, i had been running an aluminum 17pitch prop, but that prop had a spun hub and is now out for repair. i reinstalled the original stainless 19pitch prop, and although not so great for skiing, it will take me over 50 mph. this is a seville 185 bowrider, and with my alum prop i only top ended about 45 or so, with top RPM about 5800, (i watch that carefully). with the stainless at 50mph i am turning about 5200 RPM, so I am toying with repitching my aluminum prop to 18 and hopefully keep my skiing performance, but bringing the RPM's up a little at top end. The motor is finicky, usually needs some throttle to start, but for the most part runs good.

 

[dutch135]

Re: mercury 135 v-6 ,spark advance vs. power

?? no ideas?? somebody has to have something to say! thanks!

 

[JB]

Re: mercury 135 v-6 ,spark advance vs. power

Howdy Dutch.<br /><br />Just to let you know that I read all three of your posts.<br /><br />You don't seem to have a problem. I don't have an opinion on what you have done.<br /><br />Good luck.

 

[clanton]

Re: mercury 135 v-6 ,spark advance vs. power

I would have the timing recheck, you are looking for a burnt piston/s. You need to look at a factory service manual for specs, also this engine may have idle stabilizer shift kit installed as an accessory,and the timing specs are different.