Tweet
Long story – 1991 Yamaha ProV200 not used since last fall. Trailered. Full tank with Sea Foam. Fuel filter had deteriorated (was new last summer). (( Motor has had a history over the last several years of fuel system related problems, including water in gas, bad fuel pump(s) and dirty carbs due to lack of use. Last summer had water in fuel. Once water removed, ran great. )) Replaced filter and pumped (via squeeze bulb) fuel until no water coming through filter (removed and drained filter multiple times). Removed carbs. Had some white gritty accumulation. Took apart (pretty much all but main jets which have large bore openings and could see chamber they went into) and used spray carb cleaner. Everything looked good and reassembled. Started in driveway with water muff. Some backfiring, then overheated. Water tell-tale looked OK. One week later, installed new water pump repair kit (Thanks boat.net for quick response.) Found more water in filter. Kept pumping fuel and checking filter until clear. Took boat to lake. No overheating, but boat had no power. About 4000 rpm instead of max 6000. Back to the trailer. Next day, took apart (same level as above) carbs (more of the gritty gunk had accumulated) and soaked in dip cleaner (about 15-30 minutes each). Reassembled. Found the idle screws on one carb were set incorrectly (did not take them out when using the spray cleaner, but did with the dip cleaner). Friend used an electric fuel pump to get the last of the water from the tank. Purged fuel line. Back to the lake. Ran smoother, but still no more power than the day before. Same 4000 rpm. Pumped out all the gas from tank and replaced with fresh fuel. Replaced fuel pumps with another (used) set I had cleaned and put aside. Purged fuel lines. Returned to the lake. No real difference, except a couple of hundred extra rpm which may have been due to smoother water. Frustrated, late that night I realized that we had set the floats incorrectly. Instead of 5/8-inch drop, they all had more like 3/4 and too much range of motion. (Instead of setting the drop, we mis-read the instructions and we adjusted the range of motion to 5/8-inch.) Next morning, removed the carbs again (getting really good at it by now), and adjusted the floats to 5/8-inch drop and gave them all about 3/8-inch of additional travel (the 3/8 seemed to be about what I remembered them moving before messing them up). One float was stuck in the chamber due to the excess range of motion. Full of promise, returned to the lake. No difference. It ran just about the same with 1) gunked carbs and old watered gas, 2) clean carbs with mis-adjusted floats and old, no-water, gas, 3) clean carbs with mis-adjusted floats, fresh gas and different fuel pumps, and 4) clean carbs with floats corrected, fresh gas and different fuel pumps. What gives?
dilb1229
dilb1229
Comment