Chinewalker
Fleet Admiral
- Joined
- Aug 19, 2001
- Messages
- 8,902
A friend of mine is a bit of a motorhead (one of the top APBA Stock Outboard engine builders in the country) with a machine shop in his garage. He was given a blown 1980 Evinrude 140 awhile back and he's been tinkering with it ever since. He started with the basics involved with the rebuild, and installed the "best" recommended exhaust tuner, shaved the heads, installed later model carbs, ported the block, etc. The motor really screams on his 15-footer - enough that he's having trouble finding a prop tall enough to keep the Rs down.<br /><br />One other thing he's been messing with is the carb jetting. The carbs he's using have three sets of jets - low, mid and high ranges. He's been experimenting with taking fuel out of the mid-range (leaner) and has also leaned out the low and high jets a bit, too. He's an avid plug reader and has them burning a nice light chocolate. The motor sounds so much smoother than any other V4 I've ever ridden with - it's quite astonishing, actually, how smoothly it runs compared to the hundreds of others I've heard over the years. It's VERY quick,, partly due to the less than ideal propping which allows the motor to zip up the scale quickly. An added benefit of the leaner carb settings is his fuel usage has fallen off dramatically! He says he's getting about another 15-minutes of run time on each 6-gallon tank of fuel.<br /> The only thing he can figure is that these V4s come VERY conservitively jetted so that they can handle variations in running conditions, weather, fuel, oil, etc. which leaves a lot of wiggle room for someone who knows engines to really tweak them for more power and efficiency. Anyone else ever mess around with them like this? He's got about 40hours on the beastie so far with no ill effects.<br /> Just thought it might be something to ponder, if nothing else...<br /><br />- Scott
