1978 70Hp Dies at 2000rpm in Water in Gear

[seedlings]

First run out of 20 year storage. I did not rebuild the carbs because it ran great in the driveway <sigh>, and was run about once a year for 10 years, then put in storage.

In the driveway in neutral or with the prop engaged the motor runs fine, and also runs fine in the water in neutral.

In the water, in gear, the boat dies at 2000rpm on a gradual throttle up. A quick throttle past 2000 rpm and it will run full throttle, or throttle down to any rpm except 2000~2500 rpm.

So this problem only happens under load. Can a prop cause this? See the prop here:

http://forums.iboats.com/showpost.php?p=2154721&postcount=7

Full throttle is a shade over 4500rpm and 30mph.

CHAD

 

[Barnacle_Bill]

Re: 1978 70Hp Dies at 2000rpm in Water in Gear

You really need to read this first. http://forums.iboats.com/showthread.php?t=158086

 

[seedlings]

Re: 1978 70Hp Dies at 2000rpm in Water in Gear

You really need to read this first. http://forums.iboats.com/showthread.php?t=158086

Yes, that was a very helpful resource. I did all of that except the carb job and you see my prop. I was hoping for some "if it ain't broke, don't fix it" leeway.

So, I'm reading between the lines that you're saying it IS a carb problem and/or a prop problem.

I've never rebuilt a carb on anything - truth be told, I don't really know how it works, only what it does. In these threads, a carb rebuild sounds about as easy as building your own computer and getting all the drivers to work properly... in other words, it's easy if you know how. This is why I strayed away from the carb, but if it's time to learn how, then it's time to learn how.

Would a troubled carb run perfectly through all rpms in neutral (careful not to exceed the 5500 max in the book)?

CHAD

 

[jonesg]

Re: 1978 70Hp Dies at 2000rpm in Water in Gear

there are no loopholes, rebuild the carbs.
look at youtube outboard carb videos , watch how simple it is.