Re: 850 merc. hard start, wont open up
Stay away from alcohol-blended fuel and alcohol-containing additives if at all possible. The old carb components weren't made to withstand alcohol, plus it makes your motor run leaner, which is a very bad thing on old Merc's. In addition, fuel, water, oil, and alcohol don't mix real well together and you may get inconsistent lubrication to your motor.<br /><br />Your starting/idling problem may just be a simple carb adjustment. Run the carb idle mixture needles all the way in (cw) then turn them out (ccw) approx 1-3/4 turns. This should be a good place to begin checking idle mix settings.<br /><br />You'll need to adjust them further in the water, in gear. If you can't get a fast enough idle speed, adjust the Idle Stop on the distributor or on the throttle arm if you have an ADI (distributorless) ign. DO NOT adjust the Timing Stop or Throttle Stop if so marked, that'll mess up other settings that you don't want to have messed up. Just the idle speed itself.<br /><br />If you find that, upon trying to accelerate, the engine 'bogs' or hesitates, adjust both idle needles out 1/8 of a turn ccw (rich) until you get good acceleration out of the hole. You shouldn't ever need to go more than 2-1/2 turns ccw, if you have to go more there's some other problem.<br /><br />As far as the starting ritual goes, pump the bulb hard then pump a bit more. Make sure the choke shutters close fully and seal squarely against the carbs.<br /><br />You also must depress the choke button all the time you're cranking to make it work right. Rarely if ever do you see an old Merc want LESS fuel when starting, you almost have to flood them out to get them going!! If you have power tilt/trim, it helps to trim the motor all the way in, so the gas in the carbs' throats will run into the motor instead of running out the front.<br /><br />If the above doesn't work, you may need to check your carb floats and float needles for problems, or clean out your carbs. If you want to use an additive, use Seafoam or a marine-rated fuel additive such as OMC, Merc, or Yamaha offer. They won't hurt your motor in the least, and may help.<br /><br />HTH and let us know what happens........ed
