merc 1150 air leak?(2nd try)

[mellowyellow]

last time I tried to post this thread, it ended up<br />with someone elses text... weird.<br />2nd try:<br />'70 1150 2928858. low hrs. sat for 5yrs.<br />new gas tank, p/u hoses, primer bulb (old qick connect)??<br />carbs and pumps rebuilt by local shop last week.<br />prime bulb, takes a while to start cold. once started,<br />idles good, good hole shot, good acceleration for<br />about 100yds, gets on plane then loses power.<br />primer bulb is now soft! pump bulb and we're back<br />to the beginning. air leak somewhere???<br />going back to the shop today for at least new fuel<br />lines and what else? they can't test under load &<br />she runs great on the muffs of course. I assume<br />they link/synch'd but will ask. I'd like to get<br />it done once and for all.<br />where would you start and or test here?<br />as always thanks in advance for your help <br />regards,<br />M.Y.

 

[rwise]

Re: merc 1150 air leak?(2nd try)

mellowyellow<br />Is the tank vent open?<br />Richard

 

[mellowyellow]

Re: merc 1150 air leak?(2nd try)

12 gallon permanent tank and yes I tried to run<br />with the fill cap off. no change.<br />PS. tach is fried so can't give RPM's. new rectifier also installed.

 

[rwise]

Re: merc 1150 air leak?(2nd try)

on some tanks there is a valve on the pick up tube inside the tank, it is there to prevent fuel from draining back into the tank. This valve can be removed in most cases. The lines or the pick up tube could be leaking air into the line. Also even new parts are sometimes bad. Check all the connections, clamps (should set even against the hose), and fittings. Also some tanks have a filter on the end of the pickup tube, could be dirty.<br />Is primer bulb just soft or flat?<br />Richard

 

[mellowyellow]

Re: merc 1150 air leak?(2nd try)

sorry, just got back fro out of town. bulb is<br />soft, not flat. pump by hand and and gets hard<br />momentarily (until I hit WOT for a 30 sec.)<br />thanks, <br />M.Y.

 

[mellowyellow]

Re: merc 1150 air leak?(2nd try)

it's fixed <br />mechanic had wrong gaskets in fuel pump....oops.<br />he did get a chance to put it on the dyno for me<br />and she was pushing 1900lbs@5300rpm's. not bad for<br />an 30yr old motor.

 

[kinsey2001]

Re: merc 1150 air leak?(2nd try)

Hey MellowYellow, looks like I'm about to follow in your steps. Ive got (Ithink) a 72 115 Merc that I bought from a friend 2 years ago, fresh rebuild and it ran like a scalded monkey then. My rig sits out side in the hot Alabama sun.<br /><br />Anyway I followed your thread and it has given a number of ways to go and things to check-out.<br /><br />Thanks to everone, this is a great forum.