1975 johnson 70hp o/b

[ddfourdays]

I have a 1975 johnson 70hp o/b that ran fine last year.I didn't know that I had to run the motor out of fuel before storing.The boat hasn't run in 9 months.Now it takes a long time to crank,and then it won't stay crank.When I do get it crank it runs for a few minutes and just dies out.

 

[snapperbait]

Re: 1975 johnson 70hp o/b

It sounds like its time for carbs to be rebuilt...<br /><br />If your handy, have some hand tools, and a service manual then there is no reason you can't do it yourself...

 

[JB]

Re: 1975 johnson 70hp o/b

Ahoy, DD4D.<br /><br />I agree with Snapperbait. <br /><br />In addition to cleaning your carbs, clean your fuel pump, flush all old fuel and oil out of your fuel system and give her fresh mix.<br /><br />You don't have to "run it out of fuel". It is a bad idea, particularly with multiple carbs. You can harm the engine when one or two cylinders go dry and the other is still running<br /><br />What you do need to do is "winterize" the engine before storage. That will include using a fogging oil to protect the cylinders and moving parts and draining your carbs and fuel lines.<br /><br />Good luck.

 

[ddfourdays]

Re: 1975 johnson 70hp o/b

About how difficult will it be to remove the carb,and what should I know not to do.Also I need to know what all i will need to do the job right the first time with little or no mistakes.1975 johnson 70hp

 

[snapperbait]

Re: 1975 johnson 70hp o/b

On a scale of 1(easy)to 10(difficult), this job is about a 2 or 3... <br /><br />A good service manual is the most important tool here... It will tell you EVERYTHING you need to know.... <br /><br /> The best way I've found is to read through the proceedures a few times before you start the job, then follow along as you rebuild...<br /><br />You will need the following items:<br /><br />1: A service manual... Here's a link for one.. part# 156-B736 http://www.iboats.com/mall/index.cg...0953&current_category=johnson outboard manual <br /><br />2: A spray can (or two) of carburator cleaner (auto parts store)...<br /><br />3: Some small brushes for cleaning (toothbrushes work great) p.s. don't use em' for your teeth again afterwards.. <br /><br />4: Three carburator rebuild kits (one for each carb) from OMC dealer (they contain all gaskets, needles and seats, ect.)..<br /><br />5: A tube of OMC "Adhesive M".. Note.. (this will only be nessecary if you replace the core plugs)..

 

[JB]

Re: 1975 johnson 70hp o/b

If you have concerns about getting things back the way they were, a digital camera is priceless.<br /><br />Good luck.

 

[snapperbait]

Re: 1975 johnson 70hp o/b

Disassimble one carb at a time... That way you have others for a refferance....