Fouling plugs? Update 9/2/08

[bassarama]

Originally Posted by THEFERMANATOR

You may have been running lean before at WOT. 40:1 will actually lean your fuel mixture out vs 50:1. At 40:1 your fuel is denser and slightly thicker which makes it go through the jets slower. 50:1 will fatten your top end out slightly.

If I understand your theory, I’m supposed to gain a little top end speed at 50:1 because the fuel viscosity is lighter than 40:1, right?

This boat top speed has always been around 42 mph @ + - 5000 rpm’s. Saturday there were two adults and a kid plus all the fishing gear, the max rpm’s I could get was 4500.

Thanks for your expertise

Joe

[THEFERMANATOR]

No, the other way around. 40:1 is thicker so it takes more to pull it through the jets, so in turn less goes through. Also as there is more oil in the blend than fuel, every drop that goes through has less fuel in it at 40:1 than 50:1. 40:1 vs 50:1 doesn't sound like much of a difference, but when working with loopers it can be a big difference. I would still stick with the 50:1 mix and check your plugs to make sure you don't have one fouling out or something. Maybe try running your gap at .035.

[bassarama]

Got it, I'll also compare the gap of the old plugs VS the new ones, thanks.

Joe

[bassarama]

Ok, got another bug out of the motor, after checking the new plugs with a precision gap gauge, I found out the old plugs were set at .035, that said, I set the new Champions at .035 and checked for fouling, all tested fine.
If you read above, last time I was out cruising around, I couldn***8217;t achieve my 42 mph top speed***8230;I had reduced the fuel from 40:1 to 50:1 and installed a new set of champions. The fact that a few days ago I had been working on the starter motor/ground cable, decreased the gas mix ration from 40:1 to 50:1 and installed a new set of plugs, this lack of top speed got my attention***8230;

The throttle linkage was the obvious place to check and here***8217;s the problem; as you can see, the missing piece of rubber sleeve is the reason the throttle linkage didn***8217;t open the carburetors all the way, thus the lack of top rpm***8217;s > speed:



As you can see, with the new slightly over size sleeve, the carburetors linkage opens all the way, there***8217;s still about 1/16***8221; of gap between the offset cam and the sleeve, this leaves enough play so that I can engage forward and reverse without accelerating right away.



Update: 9-12-08, plugs after running at WOT, 5500 rpm's:





Here you go guys, a couple more pix for the record***8230;

Thanks for helping out

Joe

[macojoe]

Its amazing how when one thing goes a bunch goes and they have nothing to do with each other! Been there done that!
Glad you found it!

[steplift20]

hey mac is that your eye?

[macojoe]

only the shadow knows

[Joker2]

Is there any way to tell how much oil your VRO is sending the engine, and can you adjust in any way besides disconnecting altogether and mixing manually?