1989 70hp evinrude

[jepsat]

just purchased this boat & motor, motor runs very rough only idles for 3-4 seconds then dies. took the boat to local shop for repair 20 yr exp. mechanic couldn't figure out what was wrong so gave it back to me with good luck? now the list<br /> rebuilt all three carbs<br /> replaced fuel filter/fuel lines /primer bulb<br /> replaced gas/checked fuel pump/new sp.plugs<br /> compression is between 98-95 psi all three cyl.<br /> good spark all three plugs <br /> checked for vaccum leaks at all hoses and lines-<br /> none found/ timing is dead on and advancing.<br /> exhaust ports do not seem blocked as this is a <br /> low time motor. I'M STUMPED.

 

[Walker]

Re: 1989 70hp evinrude

Check spark with a spark testor immediately after it dies.

 

[jepsat]

Re: 1989 70hp evinrude

I don't understand checking spark after it dies?

 

[fireman57]

Re: 1989 70hp evinrude

To see if you are losing spark. Walker knows that you said it has good spark to all three plugs. If it starts we know that you initially have spark. As soon as it dies crank it again and check for spark to a ground. Shoul be bright blue and very strong.

 

[jepsat]

Re: 1989 70hp evinrude

I can keep it running by turning the idle screw<br />up but when shifting into gear it runs poorly then dies.

 

[fireman57]

Re: 1989 70hp evinrude

You didn't give this info in your original post. Sounds like you are sucking air in your fuel line or something was missed in the carb rebuild. Get a manual. This will help you troubleshoot quickly and effectively. Meanwhile, there was post a while back on how to set your carb adjustments. you do them one at a time. Use the search feature at the top of the page to find that post. It wasn't but a week or two back if I remember. Do the search while you are waiting for your manual.

 

[jepsat]

Re: 1989 70hp evinrude

Thanks the carbs have been gone through twice once by me and once by the boat shop mechanic<br />who also adjusted the carbs and tried leaning and<br />richening mixtures./the shop also searched extensively for any air leaks as did I, none could<br />be found.

 

[fireman57]

Re: 1989 70hp evinrude

Again, I would check for a strong 7/16" spark after it dies. If you have that on all cylinders than that is good and the guys here can eliminate that. When you get it started pump your primer bulb and see if it picks up. If it does then it's definitely in the carbs. If not Jb, Paul Moir, Joe Reeves, or the rest of the crew will come up with something for you.

 

[jepsat]

Re: 1989 70hp evinrude

great thanks for the help i'll try that saturday<br />morning are you guys on the helpline on the weekends?

 

[fireman57]

Re: 1989 70hp evinrude

These guys are here all the time.

 

[marinemech1]

Re: 1989 70hp evinrude

have your mechanic check ignition timing it sounds like the flywheel inner hub has come loose<br />just a thought and good luck

 

[rodbolt]

Re: 1989 70hp evinrude

to check for timng will require indexing the flywheel to verify that the TDC mark is actaully still at the actual piston TDC.does it sneeze or just die? does it still have the VRO pump or a plain fuel pump? has anyone looked the ign coils in the dark? coil failures that arc to ground are common with jonnys. thats why I test using a Kv tester.<br /> before looking at reeds or crank seals I would verify no fuel pumps are leaking fuel into the motor, verify the ign is capeable of doing its job and verify the fuel system(carbs) are correct. do your carbs have the black plastic covers on the top of the carbs?