1975 70hp Evinrude - doesn't get up to speed well

[jhetrick55]

My 1975 Evinrude 70hp ran fine most of the summer - good idle, good pickup, etc... Then, found out I blew the exhaust gasket and was getting water in center cylinder. Replaced the gasket, took it out to run it and no water in any cylinders, engine would idle fine, but not pick up speed very well. Eventually it would get to WOT and run well but when I put the throttle down it would take a while to get there. I checked the fuel lines right away and found the vacuum hose from the engine to the fuel pump had a kink in it... So, I've replaced that now along with all the gas lines - why not, right?

But what else should I check if this doesn't work? The carbs were rebuilt this summer already and operated fine, so I don't suspect those. Plugs have been replaced and they look to be burning clean. The timing advance hasn't been messed with and seems to operate the way it should. I am hoping this is simply some bad, old fuel line and that vacuum line. But looking for other ideas just in case... Thanks!

 

[Tim Frank]

Step 1 ~ measure compression.
Step 2 ~ verify spark with an open-gap tester.

 

[jhetrick55]

Tim Frank - thank you. I will double check that next time I am out if the fuel lines don't do the trick. I do know the compression test was good as I checked it after the exhaust gaskets. And last I knew the plugs were gapped correctly too. However, it never hurts to double check.