1979 evinrude 115 high speed troubles??

[mnessman]

I need ideas ato what is wrong with my motor.....I have a 115 hp evinrude that i jsut recently put on a boat a couple of weeks ago, I have had the motor for a year but have nor had it on a boat so I dont know the history of the motor. The problem that I am having is when we first put the motor on and took it to the lake we had problems idling along with slow and high speeds. We checked the spark plug gap and found it to be wrong so we regaped and tried it again. The boat ran better at low speeds but still had problems at high speed. I noticed that the upper carburetor was on barley spurting gas in one of the barrels but the other barrel along with the bottem carburetor was purting gas pretty good. Since we did not know how the carburetors looked inside we rebuilt them and put in a new fuel pump along with all new hoses. I had also noticed a water leak at one of the heads and replaced the gasket, so their are no water leaks now. After the carbs were rebuilt and the new fuel pump in place we took it back out. It seemed to run better although it seemed a little rough but when we tried to open it up it would start to be doing good then it would fall flat on its nose then it surge again. The engine would keep this surging action, if we idled it and then went to fuul throttle it would start to good and then it would just die down again. I dont think that the tach is working right so I can not give acurate rpms when this would occur. I haent checked the compression yet but will be doing that shortly. If any one has any ideas on what the problem is please let me know. Thanks for the help.......

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

I just checked the compression and they were all running from 140 to 145 so that rules out that problem...

 

[Sherman]

Re: 1979 evinrude 115 high speed troubles??

Sounds like you have either a vacuum leak in the fuel line sucking air into the system or the tank pick up may be clogged. Blow out the fuel lines, clean fuel tank pickup and make sure the vent for the fuel tank is open and clear.
Sherm

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

I have two tanks that I have tried both one is the built in tank that came with the boat the other is a 6 gal plastic tank that is new. I have replaced all of the fuel lines from the connector to the pump and from the pump to the carbs. If their is a vac um leak on one of the lines that would bea surprise, but I will double check all of the connections to be sure.

We have also tried to follow all of the trouble shooting tests in the repair manual and all of them seemed to be okay. Their is one question though what is the charge coil and where is it located. If we did the test correctly the charge coils might be bad because they are only showing about 89 volts (ac) I dont know if it is supposed to be in dc or ac volts...

 

[tashasdaddy]

Re: 1979 evinrude 115 high speed troubles??

sounds like it needs the timing checked and an link n sinc done.

 

[emdsapmgr]

Re: 1979 evinrude 115 high speed troubles??

Still sounds like the carbs are not getting enough fuel, perhaps caused by a fuel restriction or a weak pump. You will get the periodic stumbling at high throttle positions when the carb bowls run out of fuel. Next time you go back out, have a friend constantly prime the fuel hose bulb and see if you can get it to run high rpms' without stumbling. Was the fuel pump you put on a new one or just a different one? When you replaced the fuel hoses under the cowling, did you replace them with the special factory formed hoses or did you use bulk hose and cut to fit?

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

The fuel pump was a brand new one, and the they did not have the factory formed hoses so we had to use bulk hose, I tried to make sure that the bends are smooth so that they would not have any restrictions in them. I was thinking about trying to run them differently and see if that helps any.

Does any body know if the power packs and or the coils will cause this kind of behaviour?

I appreciate all of the help so far.....

 

[emdsapmgr]

Re: 1979 evinrude 115 high speed troubles??

The reason I asked about the use of bulk fuel hose is that it can kink when bending around tight corners and cause a fuel restriction-as you must already be aware. That could limit fuel flow to the carbs and cause your volume to be reduced-causing your problem. If possible, I'd replace them with the specific part numbered hoses from Bombardier. If you think you have an air leak at the hose connection in the lower cowl, you can try this: on my 79 85 hp, I removed the hose connection/barb in the lower cowling. Ran the fuel hose through that new hole and direct to the pump inlet barb. Made sure the hose made a wide sweeping curve to keep from kinking. That eliminates any sealing (air leak) problems at the cowling hose barb. Electrical misfires can cause erratic rpms. To check for spark, put an inductive timing light on each plug wire when the engine is under load. Each wire should flash a strong, bright light. You can see misfires and nofires this way on each plug wire.

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

I did find a kink earlier today and rerouted the hose so that there are no more kinks. We took it out and it started to run good, got up on plane and got close to 30mph then it died down some. It would still do around 20 to 24. After abot 20 min of running we had to idle down for a no wake zone when we were coming out the motor died, we were able to get it to start but every time we tried to put it in gear it died. We had to have it towed back in. I had a new set of plugs that I put in to see if it would make a difference but no luck. We loaded it back up and I just recently went down and picked up a 100 gal tank and put the motor in it, I started it and put it in gear it ran for a couple of min then it died I was able to get it to restart and I was able to get it to stay running in gear. I checked the spark with a timing light on all four cylinders while it was in gear and I had good steady spark. Im not sure what I should check next to try and figure out why it would die every time I put it in gear while we were at the lake.. Ideas, any one...............

 

[crb478]

Re: 1979 evinrude 115 high speed troubles??

If you still have good spark when the motor just dies try putting some premix in a spray bottle and with the motor in the tank spray it directly into the carbs as the motor starts to die. If it continuse to run I would look for a fuel or carb problem. If it dies anyway I would suspect the coils or powerpack or other ecectrical problems that occur once the motor heats up.

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

I willtry that the next time that I go out or if it starts to do that while it is the tank..

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

Update: I took the boat to a shop and they checke dthe entire engine, what they stated is that the engine appears to be flooding out and they stated that the plugs that were in it were not the correct ones. Thye aslo suggested that I need to spray some power tune into the carbs and see if that would help with the flooding issue. They had removed the prop and told me that it was slipping some. I got the correct plugs and some power tune from them and took the boat home. We sprayed the power tune and then changed the plugs and let it sit overnight. We took the boat back out this morning and it was still hard to start and we were not able to get the boat to go at full throttle. It seems that when the boat gets over 4000 rpm it starts to loose power. We still had some problems with it dying when putting it into gear. If anyone has any ideas I gladly welcome them.

When I rebuilt the carbs the kits did not have the measurements for the float settings and I did not see them in the book so if anyone knows what they should be for a 79 115hp rude I would appreciate it. The mechanic also stated that the spark was good along with the lower end and compression. He stated that it appeared that the motor was showing signs of flooding.

Would the prop slipping have the same type of symptons as carb issues at higher rpms, such as loosing power and surging...

I know this was lengthy but I wanted to put as much info as possible..

 

[bass or bass ?]

Re: 1979 evinrude 115 high speed troubles??

Have you made any headway with this problem? I just posted with very similar problems with my 1967 Evinrude Starflite 80 , and any solutions to your problems may be of help to me. My post was placed today at 1:00 p.m.
Please let me know how your situation turns out. If I get some possitive info on mine ,I'll let you know.

 

[crb478]

Re: 1979 evinrude 115 high speed troubles??

To set the floats pull the carbs and flip them upside down and then set the floats level to to carb bodies. How are your needle and seat test that they do not let fuel leak through.

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

I had rebuilt both carbs and the kits came with new floats and new needle and seats. I did turn the carb upside down and the float did look level with the body of the carb. I was jsut wondering if there was an actual measurement that i could check this by. The float level looked the same from one that I had not rebuilt yet (I used the old one as an example before I tore it apart). The shop asked if i had removed the welch plugs and cleaned in that area also. I told him that I did not remove the welch plugs and that after they had soaked in the carb dip that I completly sprayed all orifice openings and that they did not appear to be clogged or restricted at all. Do I need to remove these plugs and make sure that they are cleaned good. I also had trouble trying to get the jets out so I left them in place but I did make sure thay the cleaner flowed trew them freely. When I took the carbs apart they were amazingly clean so i dont feel that there would be very much trash behind the plugs and the jets. I am quickly running out of ideas so any help is appreciated.

 

[willgofishing]

Re: 1979 evinrude 115 high speed troubles??

I have a 1979 Javelin 85hp that is doing the exact same thing. I think it is the fuel lines from the quick connect all the way to the carbs. The boat was running great about two weeks ago while tubing with the kids. We did however notice a strong gas odor. That next week I was getting the boat ready for Canada and I wanted to see if I could find any leaks. Sure enough, when I pumped on the bulb, gas was shooting out of the hose with the 90 degree bend from the fuel pump to the T. I could not replicate the bend with regular gas line so I took the gas line from the quick connect to the fuel pump (because of its rigid nature) and cut part of it to make the bend. I used regular fuel line from the quick connect to the fuel pump. I was not able to run it until we put the boat down in Canada. The very first WOT it started the hesitation. The engine sounded like it was starving for gas. It would run OK around 4000 rpm's. We ran the whole week this way. The only positive thing is that it saved us a lot of gas by not running at top speed. I am almost sure it is the gas lines. I think they are collapsing @ the higher RPM?s. Changing these lines was the only thing I did before it started this prob. I am going to order new lines today. I will let you know if this takes care of the problem.

Thanks,

willgofishing

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

I was reading on another post about the thermostats, how can you tell if they are not working correctly? I can start the motor and let it run for quite some time and the cylinder heads are only warm to the touch. Could this possibly be a cause to the problems that I am having. I was told that the plugs are fouling, I have removed the carbs and double checked the floats and all of the passage ways, they all appear to be good. I looked at the reeds and the best that I can see id that they look okay. When I removed the plugs earlier they appeared to be slightly wet. Please help as I am running out of ideas...

 

[petryshyn]

Re: 1979 evinrude 115 high speed troubles??

Still sounds like the carbs are not getting enough fuel, perhaps caused by a fuel restriction or a weak pump. You will get the periodic stumbling at high throttle positions when the carb bowls run out of fuel. Next time you go back out, have a friend constantly prime the fuel hose bulb and see if you can get it to run high rpms' without stumbling.

Have you done what emdsapmgr suggested?
It does sound like your bowls are running low due to supply issues. Do what he suggests and let us know....

 

[mnessman]

Re: 1979 evinrude 115 high speed troubles??

Sorry I didnt mention that before, but I did try that one time that we took it out and it didnt appear to make any difference. When the motor started to surge I started to pump the buld and it didnt seem to make much difference. It might have accelerated for a split second but that was it, or it was just the surging that it was doing already. I cant think of anything that would create the fuel problems but maybe I am missing something.. Thanks for the help.

 

[willgofishing]

Re: 1979 evinrude 115 high speed troubles??

Just replaced all the fuel lines on 1978 Johnson 85hp with factory fuel lines. Replaced bulb and added an extra fuel filter. Took off prop and ran engine in tub of water between 5000 and 6000 rpms. No surging at this high rpm. Hope it fixed the problem. Putting it in the water tonight to test again with prop. Taking it on vacation this week to go tubing. Hope all works out.

Will let you know progress.

willgofishing