older evinrude

[recondelta54]

I have a84/85 model 85hp evinrude motor I just rebuilt the water pump alls great there.I bought new plugs & installed them motor idles good,no problems here.took boat to lake to test run.motor started up no problem when I throttled down [opened it up] the motors rpms got up to 1800/2000 rpms & there was a power loss & it stalled out.restarted the motor & slowly excellerated motor ran fine at 1200 to 1500 rpms ran around lake for 10/15 min.opened up throttle same thing it stalled motor temp was fine no overheating idle was lower than it should be but I didn't adjust idle from 500/550rpms to 750rpms I don't really know which way to go to correct this what I suspect is a electrical problem what would cause this to happen?spark advance?coil break down?ect? I could use some guidance of which direction to begin & omit this so I can use the boat & fish some.Thanks

[Riverman]

I would start by going through the carbs, my 60 did just that, the main jets were full of crud from lack of use.

[recondelta54]

had rebuilt carbs ,although the motor set for @ a year I don't know that crud would build up that fast although without a fuel additive it could be possible any othe ideas assuming that alls well in the fuel end of this project

[Forkin' Crazy]

When it starts to die, push in the key to see if it picks up. If it does, it is fuel related.

It sounds that way to me anyway. Take it for what it is worth, but I could clean and build a set of those carbs blind folded. I am sure Riverman could also.

[mirage243]

had rebuilt carbs ,although the motor set for @ a year I don't know that crud would build up that fast although without a fuel additive it could be possible any othe ideas assuming that alls well in the fuel end of this project

With all the ethanol that is in fuel now, a year is MORE than enough time of sitting for you to have serious fuel related issues. Run the motor on the a flush kit connected to a garden hose, while the motor is idling, remove each spark plug wire, one at the time, (use some type of device to keep from getting shocked, otherwise we'll all get a good laugh when you tell us the story):D when you pull the plug wire, you should be able to hear the engine change tones and when you put the wire back to the plug, you will hear it spark, if you confirm that you have spark on all cylinder's, then more likely than not you have a fuel related problem.

Send me your address and I'll mail you a bill.:D

By the way WELCOME to SCREAM and FLY:thumbsup:

[Robby321]

Few things ya can do that are easy. I bet its fuel..(sounds like it), so try the choke as suggested, see it it picks up. Also have someone pump the primer bulb and see if that helps. I would for sure, get a new hose/bulb too..and any inside lines. Swell with age and the crap they call gas. Could be a shot fuel pump. Ya rebuild that with a kit?
On checking for spark, few ways to check. One is a timing light. Hook to one wire at a time, look for the flash. Good way to see whats going on out in the water while under way too...(one driving, one checking). Easy way to kill a cylinder on the hose without pulling a wire, is a simple small wire. Cut 4 pieces, strip the ends, and put one end under the rubber wire cap so ya know its going to ground the plug. Fire it up, touch one wire to a good ground. That a sure way to know the plug is firing, where as a timing light might show juice, but don't mean the plug is firing.
But would first make sure the whole fuel system is clean, and new rubber lines, and a good pump. All it takes one little piece of crap, to plug a carb. Good luck..those are real workhorse motors.

[stokernick]

dirty carb IMHO

[Robby321]

dirty carb IMHO

Yep..:iagree:...old middle 80 Rude electrics are damn near bullet proof.

I'm betting a shot fuel pump diaphram...if not more. but I would do zip, without a pump rebuild. Kits are cheap, and have a source old Johhny/Rude parts..if wanted, will post. Dude goes back to the 50's in parts. Also a source old motor decals, for a restore. Do it now, but links the house puter..I'm on the shop laptop...(getting little done, but I'm still.."in my sanctuary!"....love messing boats, bikes, a shop, more tools than a 2 legged should own, and ..well, ya know what I mean!:cool:
Gotta comment here..reading some post ya here. One, who I forgot screen name, caught today...the end "sig sing off".
"If it aint broke, fix it until it is"...(had me grinning all day!)..:thumbsup::D