Need help with 1976 merc.

[boaterntexas]

Well secound fishing trip stull ruff. The ole 1976 mercury 115 hp motor on a 17' bass boat bogs down and dies when given more than 1/4 throtle. it seems to run fine when completely trimmed down but if not all the way trimmed down if will seem to get flooded and eventully die.. some backgroud info, a couple of weeks ago we ran agroud and ran the motor through some really thick nasty mud, since then I have change the impeller which seemed to have a really tight fit, and I had to force it into the housing, I believe everything went back together fine, when ran offshore the motor seems to work fine, even at full throtle. It just that in the water it runns badly, where are using flushing muffs when offshore. There is alot of water comming out of the exhuast, (the top 2 slots near the head unit) I foud a lose screw on the side of the motor opposite the pee hole, opposite the fuel pump. if looking at the motor from the rear the bolt is on the lefthand side at the rear of the motor. this loose bolt seemed like it was holding the side cooling panel on or something. there was water comming out of the hole the bolt should had been in, I tried to tighten it, but was on the water and couldn't access the bolt well enuff to tighten it fully.. <br /><br />think I have given all the info I've got.. thank for you time of reading this and any info you may have... <br />Thanks, <br />THomas

 

[steelespike]

Re: Need help with 1976 merc.

Usually when a motor bogs it is a fuel supply problem touch the choke if the motor responds<br /> it is a fuel problem.Running under a load is a lot different than on the muffs.<br /> Be sure water is coming out of the telltale.<br /> after running a little feel the head.Should be to hot to hold your hand on but not so hot it burns you. cooling system could be plugged with mud.A working telltale indicates water flow but weak telltale or no telltale doesnt necessarily mean no water flow.Could just be plugged telltale.

 

[mellowyellow]

Re: Need help with 1976 merc.

agree with steelspike. have the same motor and when<br />this happened to me, it was a stuck float. try<br />squeezing primer bulb and see if gas is pouring <br />out of the front of carb.<br />good luck,<br />M.Y.