85 vs 115 carbs results

[joe outlaw]

I went out and tried the 115 carbs on the 85hp motor and they worked. The only thing I found to be a sore was when it would idle. It wanted to shut off. I played with the low speed needles like the fourm said and think I was close but not close enuff. In the fourm it states to turn them in an 1/8 at a time and the rpms would go up and to back the rpms back down. question is what do I adjust at that point to get the rpms down? I started out snugging them up then out 1 and 1/2 turns out then went on like the fourm said. what do I do then to get the rpms down. and that motor max rpms are 5000 It went up to 4600 which is fine with me because it was moving around 35 mph.any suggestions?

 

[emdsapmgr]

Re: 85 vs 115 carbs results

If you have carbs that have idle adjustment screws, you have carbs from back in the 1971 era. The idle screws are to be set to balance (smooth out) the idling between cylinders of the powerhead. The actual idle rpm is set by adjusting the idle timing up or down. Your idle timing may be set too high. That engine idle should be set when warmed up, sitting at rest in the water-floating. Idle speed should be between 650 and 750 rpm in gear. You should select a propeller for that engine which will let it run 5500 (or slightly higher) at top end. If you run the engine no higher than 4600 at top end, you are actually "lugging" the engine. This causes sluggish holeshots, poor poerformance and bad fuel economy. You need to reprop it.

 

[joe outlaw]

Re: 85 vs 115 carbs results

thanks for the feed back. Now I think I know what to do. And you are right the timing is set at TDC when the book says it should be at 4 degrees atdc. I will play around and see If I can get it close to where it should be. then I will get into the prop change. thanks.

 

[MAW31]

Re: 85 vs 115 carbs results

I have an 88SPL and have been contemplating putting 115 carbs on it.

besides just working, did you get any performance or greater top end out of it?

thanks.

 

[emdsapmgr]

Re: 85 vs 115 carbs results

MAW, you may want to start your own thread on this subject. I'll send you a PM.

 

[joe outlaw]

Re: 85 vs 115 carbs results

I went back to the 85 hp carbs and found them to work the best. Low speed no problem;high speed no problem. I think im going to change the prop to get the rpms up to 5500. The 115 carbs were over fueling at low speed.

 

[hamburgerman]

Re: 85 vs 115 carbs results

I been looking for a set of 115 carbs what year? pm me if intersted