76 johnson 70 hp bogg's

[nedct]

I just got my first boat,it's a 15'6" 1964 Chris Craft (corsair)glass with a 1976 70 hp johnson. It is bogging down when I hit wakes,it barely get up to 10 mph. if i pick up the motor and move it side to side it work's fine till the next good wake. It goes great when it is right(30-35mph with pep)(how fast should it go?)...I changed the plug's and the coil's. I also drained the carb's through the bowl screws, forcing fuel through them individualy, cleaned fuel filter,changed primer bulb and fuel line all this and it still suck's. Also it will die on acceleration to mid or full throttle after I shut down then restart after sittin for a few,i have to play with the throttle to get it right.

 

[Bass Runner]

Re: 76 johnson 70 hp bogg's

Have you decarbed the motor? Kind of sounds like you need to clean the carbs and put some kits in them, but try the decarb first if the reeds are all gummed up it will hurt the performance, the speed will depend on what pitch prop you have, how heavy your boat is ( if i remember right a friend had a 16' cc day cruser and it weighed a ton, and the hull on those boats wasn't the cleanest design, but that aside, try the above and you might check the link and synch, but it sounds like a fuel problem to me.

 

[nedct]

Re: 76 johnson 70 hp bogg's

thank's Bassrunner .. what is involved in decarbing a motor? the boat is about 800lbs i think.. does that sound right? I lift it to put it on my hitch and it's not to bad...if that hold's water for ya..ha ha what am i looking at in $$$ terms for the carb kit's? and decarbing..

 

[nedct]

Re: 76 johnson 70 hp bogg's

Bassrunner? you there???

 

[Brew2]

Re: 76 johnson 70 hp bogg's

I stand to be corrected, but.... I believe carb kits will run you about $15-$20 per carb. Decarb spray is probably somewhere around $15 a can.<br /><br />Also would be a good idea to buy a manual for your motor. If this is your first go at rebuilding the carbs, the money you spend on the manual will be repaid 10 fold in frustration avoided by the time you are done.<br /><br />Good luck!

 

[nedct]

Re: 76 johnson 70 hp bogg's

thank's Brew, i appreciate the input..I got a manual right after i got the boat..already paid for itself..

 

[nedct]

Re: 76 johnson 70 hp bogg's

hey water walkers..I did the waterpump assembly but bought the wrong fuel pump. going to have the carb's done this week also.. should i decarb it before the kit's are put in ?..

 

[Brew2]

Re: 76 johnson 70 hp bogg's

Shouldn't matter much whether you do decarb or carb kits first...just as long as both get done.<br /><br />Sounds like you are taking it somewhere to have the carb kits put in.... if you did the lower unit service yourself and you already have the manual, I bet you could do the carbs yourself in a couple of hours tops. Just a thought.<br /><br />Good luck!

 

[nedct]

Re: 76 johnson 70 hp bogg's

I don't feel 100% sure i can... with the sync timing and stuff.. but i think i'll read it through. i have a Guy who's last name happens to be (Johnson) doing it.!! Ironic huh?..he comes to the Boat too.. i think i'll watch him do it, then try my luck doing the carb's and ring's on an 1988 88 special someone offered me for 2 bill's.. i asked in here and heard they were work horses.. what do you think about them..?? all opinion's are welcome..

 

[nedct]

Re: 76 johnson 70 hp bogg's

It took less than 2 hrs to do the water pump assembly... only had to heat 2 of the case bolt's lightly.. a tap here and a little pry there everything else went mint..<br />I had an estimate of 200 - 500.00 for the job.<br /> i guess they heard 76 and thought big problem's or they are just scum,, this motor seem's to be in very good condition..it was 51 bucks for the part..<br /> Fish On !!

 

[nedct]

Re: 76 johnson 70 hp bogg's

seemed to have fixed the bogging with the waterpump assembly... Nice!<br />Fish On!!