'65 Evinrude Starflyte 90HP Problems

[Sunliner]

Just bought a boat with this engine.
Seller claimed to have recently spent $800 on it. Much new wiring inside the cowl with a new starter solenoid and a new single cable push-pull steering rack. Looks like new plugs and wires but no evidence of much else being touched.

Problems are:
1) Starts and runs fine. Will run well at slow to moderate speeds indefinitely. Idles fine. At full or near full throttle after about 2-3 minutes it surges a couple times like it was given more throttle or an extra cylinder cut in and then slows down and stops like it was running out of gas. Then it will re-start after a few tries and resume operation same as before. Once it seemed the battery was run down even though recently charged upon trying to restart. But after a short period, it cranked as though the battery was fully charged. Fuel delivery from the tank is good. Battery is new.

2) When turned off, the prop freewheels but when running it is stuck in forward regardless of the shift/throttle lever position (fwd, N, reverse.) Shift wires running into the lower housing appear new (blue and green.) Not sure about the Johnson Electromatic shift mechanism but wiring appears new and professionally done there as well.

Questions:
I'm using 50:1 mix. Is this correct? Could the dying problem be overheating at high speed causing it to seize or bind up? Is that why the battery seemed low on restart but after sitting a minute or two seemed OK? I'm getting water flow as though the impeller is OK but do not know if it is sufficient - not experienced with outboards. There is a long narrow SS plate on the lower port side with a 3/8"-1/2" hole which I assume is the water intake. Is this proper? Seems pretty small. Also, the manual choke lever position inside the cowl does not have much effect once the engine has been running and is warmed up. How can I diagnose the shifting problem? Is it possible to jump the wires to test it?

I'm mechanically inclined and experienced with other things but inexperienced with outboards. I've ordered a manual but hope someone can give me a tip or two to get started in advance of it's delivery.
Thanks for any help!

 

[coolguy147]

Re: '65 Evinrude Starflyte 90HP Problems

check compression spark replace impeller if not done so lately change and check gear oil

to your problem see if pumping primer bulb will help.

 

[F_R]

Re: '65 Evinrude Starflyte 90HP Problems

Just bought a boat with this engine.
Seller claimed to have recently spent $800 on it. Much new wiring inside the cowl with a new starter solenoid and a new single cable push-pull steering rack. Looks like new plugs and wires but no evidence of much else being touched.

Problems are:
1) Starts and runs fine. Will run well at slow to moderate speeds indefinitely. Idles fine. At full or near full throttle after about 2-3 minutes it surges a couple times like it was given more throttle or an extra cylinder cut in and then slows down and stops like it was running out of gas. Then it will re-start after a few tries and resume operation same as before. Once it seemed the battery was run down even though recently charged upon trying to restart. But after a short period, it cranked as though the battery was fully charged. Fuel delivery from the tank is good. Battery is new.

2) When turned off, the prop freewheels but when running it is stuck in forward regardless of the shift/throttle lever position (fwd, N, reverse.) Shift wires running into the lower housing appear new (blue and green.) Not sure about the Johnson Electromatic shift mechanism but wiring appears new and professionally done there as well.

Questions:
I'm using 50:1 mix. Is this correct? Could the dying problem be overheating at high speed causing it to seize or bind up? Is that why the battery seemed low on restart but after sitting a minute or two seemed OK? I'm getting water flow as though the impeller is OK but do not know if it is sufficient - not experienced with outboards. There is a long narrow SS plate on the lower port side with a 3/8"-1/2" hole which I assume is the water intake. Is this proper? Seems pretty small. Also, the manual choke lever position inside the cowl does not have much effect once the engine has been running and is warmed up. How can I diagnose the shifting problem? Is it possible to jump the wires to test it?

I'm mechanically inclined and experienced with other things but inexperienced with outboards. I've ordered a manual but hope someone can give me a tip or two to get started in advance of it's delivery.
Thanks for any help!

Well he might have spent $800 on it, too bad he spent it in the process of fouling everything up. Where to begin....?

It might be overheating at high speed. That plate on the side is the remnants of what at one time was a flushing attachment with a garden hose fitting. You need to find the right kind of plate to go on there. It had a rectangular opening with a screen. The opening is for admitting water when running in reverse. Too large an opening will allow water to escape when running at speed in forward. Look right above the propeller, there should be an exhaust outlet held on by two screws. In the forward side of that outlet should be an opening with a screen. That is the main water inlet. If the outlet part or the screen is missing, it will overheat at speed.

Shifting: Be Careful What You Do!!!!!! Somebody has already messed it up, and getting it wrong can cost you some big bucks!!! Instantly, that is. With the motor not running, check the voltages on those blue and green wires leading down to the lower unit. There should be 12V on green when in forward gear and 12V on blue when in reverse gear. Zero voltage on either wire in neutral. And NEVER 12V on both wires at the same time!!! If it is wrong, the wiring and/or shift switch is screwed up. If you manage to get 12V to both wires at the same time while running, it will instantly break either the drive shaft or one of the clutches.

50:1 is correct. I don't know what to say about the other running problems yet. It is mandatory that you address these two things before proceeding any further.

 

[Sunliner]

Re: '65 Evinrude Starflyte 90HP Problems

F_R:
Thanks for the info. I'll check the voltages tomorrow. I'll also check the water inlet. There is a spray of water coming out the upper exhaust port when it is idling but I do not know if it is sufficient. The engine runs well indefinitely with no problem at idle to half throttle but at higher speeds it will eventually stall after running fine for 1/4 to 1/2 mile. After stalling it will generally restart quickly within a minute or two and again run well until another extended high speed run is attempted. Fuel tank and lines are new and topped off with fresh fuel, hard primer ball, etc. so it is not a fuel supply restriction. Maybe fuel pump or fuel filter?

Thanks so much for your advice!

It is mandatory that you address these two things before proceeding any further.

 

[F_R]

Re: '65 Evinrude Starflyte 90HP Problems

F_R:
Thanks for the info. I'll check the voltages tomorrow. I'll also check the water inlet. There is a spray of water coming out the upper exhaust port when it is idling but I do not know if it is sufficient. The engine runs well indefinitely with no problem at idle to half throttle but at higher speeds it will eventually stall after running fine for 1/4 to 1/2 mile. After stalling it will generally restart quickly within a minute or two and again run well until another extended high speed run is attempted. Fuel tank and lines are new and topped off with fresh fuel, hard primer ball, etc. so it is not a fuel supply restriction. Maybe fuel pump or fuel filter?

Thanks so much for your advice!

I'd suspect the fuel pump. A new filter comes with the kit.
http://www.iboats.com/mall/partfind...gd_poid=109271&gd_row=80&**********=154156439

 

[Sunliner]

Re: '65 Evinrude Starflyte 90HP Problems

Removed and disassembled the fuel pump completely. Diaphragm is good. Everything is good. One way flow without leaking, etc. The pulse hose from the crankcase had some surface age cracks at the clamp so I replaced it. Ordered a rebuild kit just in case.

Checked shift voltage from the control unit at the helm. Green has 12 volts in all positions. Blue nothing. I'll check out and repair the control unit or add a
3-way toggle switch for manual shifting.

Thanks again!

I'd suspect the fuel pump. A new filter comes with the kit.

 

[Sunliner]

Re: '65 Evinrude Starflyte 90HP Problems

Shifting is fixed!
Switch lever inside the control box was bent aside and stuck in the forward position due to someone assembling it improperly. Also, the rewire was reversed so Fwd was reverse, etc. You were right F_R about it getting fouled up!

 

[Sunliner]

Re: '65 Evinrude Starflyte 90HP Problems

Tried it again for a hour or so.
Shifting is fixed.
Still stalling after a few minutes high speed run. Appears to be some steam vapor behind the boat at times. I'm suspecting overheating now... New impeller ordered. Pulled the plugs and they look good. Still runs good at low speed.
Help!

 

[Sunliner]

Re: '65 Evinrude Starflyte 90HP Problems

Not getting much response here but for those interested, the problem went away with a new tank of fuel and proper oil mix. I tried to check the fuel that was in the boat (when I bought it) to see if it was an oil/gas mix but could not tell for sure. I suspect there was not enough oil and the engine was getting hot or trying to seize. At this point, it runs well and no longer dies during extended high speed runs but it does surge periodically as though another cylinder is cutting in or the throttle is suddenly opened further (even though it is at the max throttle stop.) This happens fairly often in hard high speed turns. I replaced the plugs and will check to see if one is getting fouled before the otheres. I also bought a compression gauge to check that. Anyone have advice on other sources of this behavior like electrical or timing or carb/mixture? Just trying to get the beast running properly and hoping to educate others in the process. Also looking for a new prop. Thanks!

 

[Sunliner]

Re: '65 Evinrude Starflyte 90HP Problems

Update:
Bought a factory service manual online. It doesn't offer much advice on troubleshooting the carb.

I took the 4-in-1 carb apart and could not find anything wrong - it was pretty clean and all intact. The only thing that seemed strange was the 4 floats seemed irregular - that is to say their open and closed positions varied depending on how the metal tangs which limit their movement were bent. As such, I adjusted the floats until they all had similar open and closed positions and reinstalled them. I also adjusted the idle jets to 3/4 open turn as a starting point and fired it up. It ran much better and the high speed surging has stopped. Not sure if it is developing full power as the peak surges before seemed more powerful but what used to be an unpredicatable beast now functions in a fairly normal fashion.

Anyone out there have any experience with this sort of thing? Or, am I now the expert on this engine?

Next effort will be syncing the throttle and advance links.