1979 evinrude 115hp idle and starting problem

[shift4life]

I have a 79 evinrude 115 model 115999r that the po had rebuilt due to one of the cylinders loosing compression. he had all of the cylinders bored to the next size up piston. I have not done a compression test on the engine. it is hard to get started. I can eventually get it started sometimes it starts right up for me other times I think it is getting flooded. when I get it started it seems to idle to low and often shifting between gears it will die. them I have to deal with getting it started again. when it is running anything past idle is seems to run fine wot it will get up on plane right away with out a hiccup. but the biggest problem is it dies when switching gears. since I got the boat I have drained all of the old fuel from the tank replaced it and put new plugs in. the old plugs had a greenish tint to them. I would guess either I should tear the carbs down and clean them or try to adjust the idle. I do not have a manual for this engine yet and was not sure if tearing the carbs down for a cleaning would un sync them.

 

[interalian]

Make sure the choke plates are closing fully. You might need to adjust the linkage. These motors like a lot of choke/prime to start, plus raise the fast idle lever fully.

And you can raise your idle speed - there's a slotted screw on the throttle arm - it faces forward and is just above the pivot point. Make sure you don't get the throttle cable in a bind when you raise the idle - you might have to loosen the cable trunnion at the bottom of the silencer.

 

[shift4life]

OK I will look into that I thought the idle had something to do with timing for the motor. I know my way around engines but outboards are new to me and a little different from what I know. my boat does not have a fast idle lever though it has just the throttle control and to put it in neutral I have to pull out on it. and my electric choke is engaged with the key.

 

[emdsapmgr]

That engine is made to idle by using special carb idle circuits and jets for idle only. The idle mode must be setup and depends on a couple of critical factors. 1. When at idle all the engine butterflys must be closed completely. If the butterflys on one carb are ajar, it won't idle well. 2. The idle jets are dedicated just to idle. They are small and can tend to crud up with debris that accumulate in the jet due to years of improper winter storage. If one idle jet is restricted, the engine will miss occasionally when idling. This is not a spark miss, but a lean condition. Called a "lean sneeze." 3. The idle rpm is not set by the carbs, but rather it is adjusted by tweaking the timing of the engine. The idle rpm should be set between 650-750 rpm's. Set when the boat is floating normally in the lake, and the engine is shifted into forward gear. Can't set it on the trailer. If all of these factors are not perfect, it won't idle well. As soon as you move the throttle barely off idle, the engine is fed by the high speed jets, and the engine may take off and run fine through the rest of the rpm range. But at idle, it only runs on the idle jets. There is a process called "sync and link" which is an adjustment between the timing of the engine and the carb butterfly opening. You may want to refer to an original factory manual and look through this somewhat complicated adjustment process.

 

[shift4life]

Should I look into cleaning the carbs before trying to adjust anything. I think I will just have to order a service manual for the engine. any preference on what is the best one to order for that engine. thanks

 

[emdsapmgr]

Don't waste your time on a Clymer or Sealoc. Get a factory original. Check out this factory site: outboardbooks.com They handle all of the OMC/Bombardier publications.

 

[shift4life]

OK I will look into a factory manual. I started to rear the carbs down I would put the pictures up by the file size my phone takes is to large to upload. are the idle passages you were talking about the 4 small holes in the throat of the carb. and If you take the small screws out of the side of the carbs you can see a small jet that is within that passage? I spraayed carb cleaner though that passage where it would feed from the bowl and it comes out of all 4 holes so I am guessing those are not plugged. also are the two long brass jets the big ones the high speed jets? I tried to unscrew one but it is in very tight and I do not want to strip it.

 

[shift4life]

is it necessary to remove all the Jets to clean them or just make sure they are not plugged up

 

[Bosunsmate]

is it necessary to remove all the Jets to clean them or just make sure they are not plugged up

Often its behind them down the tubes that block. So i always remove and spray carb cleaner down them and make sure it comes out somewhere with high velocity, not hindered

 

[emdsapmgr]

There is a special screwdriver that Bombardier sells just for removing their jets. Special tip so you won't damage the jet during removal. Handy tool to have: part number 317002. I agree with the guys. Spray some Gumout aerosol cleaner down a specific passage in one carbs. Note the volume of spray coming out of the other end of the passage. Then do the same passage on the next carb, noting the volume of spray coming out of the other end of that passages. Point is, that you want to compare the spray volumes of similar passages in each carb. Doing it by comparing the same jet will give you an idea if the flow through each jet is similar to the same jet in the other carb. You want identical flows thru identical passages. Best to make sure the carbs are clean, then move on to the other tune-up aspects.

 

[interalian]

There is a special screwdriver that Bombardier sells just for removing their jets. Special tip so you won't damage the jet during removal. Handy tool to have: part number 317002.

Here's my Joe Reeves approved jet remover. Also my home-brew piston stop for checking TDC, and my piston pin clip installation driver. $0 solutions FTW!

 

[shift4life]

the black intake cover seemed to possibly have a gasket or it just had some rtv to seal it. is it necessary that it is sealed with a gasket or is it just supposed to be bolted on with no seal. thanks

 

[Bosunsmate]

If its the cover i think you are talking about, the front one, there is a cheap gasket on them

 

[shift4life]

I will have to order that gasket for the time being I just put the cover back on. boat starts right up! I will have to do a lake test let it warm up and see if cleaning the carbs solved the idle issue. I will let you guys know if my idle issue has been solved too. thanks guys

 

[rob 135]

My front carb cover has drain hose .Carb fuel that is spit out of carbs is sucked back into crankcase.