Minor Help Needed 1987 Evinrude 15HP 2-Stroke

[deepfriedchicken]

Greetings, I've been working on this evinrude for a few days. It had been sitting for 10 years. It's one with an electric start, steering wheel vs. tiller style...I don't know the proper terms. I rebuilt the carb & cleaned it, did the lower end oil, water pump kit...And it started right up. Miracles DO happen.
Anyway, once it turns over which is pretty quick I have to get my hand on the gas and give it some quick or it dies. I can run it forever that way with the choke all the way off after a minute, but as soon as I try to reduce it to idle, it instantly dies. Then it's tough to restart. I can't find anything to adjust the idle and I know it's close to right otherwise so I am leery of making it worse and am hoping someone can steer me to what's wrong and adjustments. I have the fuel mixture at 1 1/2 turns out if that helps. Opening day is Saturday so I have tomorrow to work on it. Any help would be greatly appreciated.

 

[glassmaster68]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

youre prob going to have to check the carb again,clean all air and fuel passages ,youre obviously getting fuel on the high side,their is prob some gunk somewhere in your your low side in your carb,spec since this thing has been asleep for a while,try that and see what you get

 

[iwombat]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Sounds like your idle capillaries are clogged. Did you give the carb a soak or remove the core plug that covers the idle capillaries? That's where your problem lies.

 

[Christopher A. Boody]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Good luck, I will be watching this thread closely, I have a 9.9 and it is doing the same thing... as soon as I throttle down from the 'shift' position, it just dies... I cleaned and rebuilt the carb, no change. Got another carb- and still no change... I am looking for someone with other ideas

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

I hate to say it, if it won't idle the carb is still dirty.

 

[Christopher A. Boody]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

not my first rodeo with carbs.... pulled all the plugs soaked for 4 hours in carb cleaner and probed with monofilament under a lighted magnifying glass... + blown out with air... same exact sympoms with both carbs... second carb was off of a fully functioning sibling

 

[deepfriedchicken]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Ok Gentlemen,
I had to do the water pump side 2X so I guess I shouldn't be surprised. Just glad you're not asking to line up shift linkage, copper line and drive shaft splines all at once (again). Not that it was hard. 3,5 tries I had it. Just threw 1 screwdriver. I trust your experience. If anyone could point me to which jets/parts are low-end and idle I will pay particular attention when I clean it (again). THANKS GENTLEMEN for trying to help this newbie

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Low end is top of the carb, welch plug at the top covers the idle ports, make sure the needle isn't bent or broke off and stuck in the carb.

 

[deepfriedchicken]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Thanks,
do I need to invest in tools for the welch plugs? I ignored them on my rebuild.

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

not my first rodeo with carbs.... pulled all the plugs soaked for 4 hours in carb cleaner and probed with monofilament under a lighted magnifying glass... + blown out with air... same exact sympoms with both carbs... second carb was off of a fully functioning sibling

As for yours, half pull the choke when you idle down, see if it makes a difference. What's your motor health, this is kinda a thread blend but hey it may help for both. Spark on both, good compression, history of things tried and repairs?

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Thanks,
do I need to invest in tools for the welch plugs? I ignored them on my rebuild.

Not really, sharp punch to pierce them and pry up and out. Install, convex side up and flatten with a 3/8 extension and a hammer, seal edges with clear nailpolish.

 

[deepfriedchicken]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Ok,
I will pop them out tomorrow. Thanks for removing the fear of pulling them which I had. I figured I'd never get the new ones on. Let you know how it goes tomorrow. Jim (DfC)

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

They are easy to remove and replace, no fear!!!!!!!!

 

[deepfriedchicken]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Think there's a pretty good chance that's the low-end rpm issue? I admit it would have been low on my priority-list to try, but THAT is why I decided to ask for help...

 

[Christopher A. Boody]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Yeah, I know- I was just going to watch where this thread went, but I could not help myself. I dont know to much about the history, My neighbor moved away, and I got it cheap. He told me about the idle issue, and I thought for sure it was the carb. But... we will see. the compression is 25 on the first puff and about 77-78 on the forth puff approximately. it runs very well at "start" and above. There has been no other repairs done in recent years, that he had admitted to,

The Choke will not save it from stalling... I tried the only thing that will keep it running is to twist the throttle open a little bit... the spark is good and it has new plugs.

I am really interested to see if anyone has anything to say about throttle linkage.... because the carb roller cam is coming off of the timing lobe right at the "shift" mark .... What would control the idle speed if the carburetor roller is not contacting anything at low speed... I thought perhaps my gear linkage was out of sync, but the rpms seem right for the other set points... " shift /start" so it does not seem like it is way out of wack I dont have a tach yet.

do these motors use spark timing in some creative way for trolling speed idle control? or do I really need to focus on the synchronization of the throttle and timing?

Thanks

 

[Christopher A. Boody]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

by the way,... the neighbor said he has run it this way for years.... I like to go much slower and I would perfer to have slow speed control. I particularly liked the idea of the trolling speed fine tune knob for trolling the river so I can finally free up a hand

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Well if yours is an 87 as well the adjustment is at the end of the tiller handle, smaller knob to control it. If you look at The Machinist site SSCHAPTERPSA

http://www.sschapterpsa.com/ramblings/Johnson 9.9_15.htm

He talks about the platic top carbs warping, don't know if this pertains to DeepFriedChickens problem, the plastic carb top can warp allowing for air issues.

Read this section about timing

http://www.sschapterpsa.com/ramblings/Johnson_9.9_carb-fuel_pump.htm

That sounds like it's an issue for you, something is out with the tiller vs carb sync.

 

[deepfriedchicken]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Thank you for your help.
I popped that Welsh Plug and sprayed carb cleaner like there was no tomorrow. A surprising amount of junk came out of there. I soaked it for quite a while to make sure, blew it out with compressed air, did everything I could think of and what a difference. It's running MUCH better. Still idling a little low and will die off, but its very minor compared to what it was. The difference from where it was is remarkable. I'm going fishing tomorrow! Guys like you cool dudes that lend your expertise here are the best. Thanks for your help.

 

[bktheking]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

Now do you see that it's the only way to do the job, you CANNOT get at the idle ports properly unless the plug comes out. Glad it's good to go!

 

[Christopher A. Boody]

Re: Minor Help Needed 1987 Evinrude 15HP 2-Stroke

BK,

I read the article and spent another couple of hours of quality time poking around, my motor is a 1980 model, and indeed they use ignition timing to change idle speed. The repair manual does not help me much after this, what I do know is that I can back the throttle down all the way and I still have a great spark.

The throttle timing mark on the carburetor roller vs the throttle cam is dead nuts on.... Carburetor to intake gasket seems tight, What else do I look for?

If I manually hold the throttle in position while I turn the twist grip to Idle the motor will continue to run albiet a bit poorly.... I know someone is going to tell me it is the carburetor still, but I opened both the original and the spare up again last night and found nothing. I have them resoaking again today while I am at work... Any thoughts?