How to adjust idle speed on a 1984 Hp Evinrude?

[Fisherman_7]

Have a 1984 Evinrude 115HP (E115TLCRD). Engine idle is too low even after motor has been running a good while. Engine dies when put it into neutral. Where is the adjustment for this?

 

[multimech]

Re: How to adjust idle speed on a 1984 Hp Evinrude?

Ok, you have no adjustments on the carb for idle speed. The jets are fixed.

The idles speed will depend on a number of things.

1. Know what the compression is for each cylinder. Is one cylinder much lower than the others? for example.

2. Ensure you have spark on each cylinder. Check it with a spark board with a 7/16" gap.

3. Make sure the fuel is clean and FRESH.

4. Perform a synch and link on the engine.

5. Ensure you have at least 4 BTDC as the starting idle timing. You may go up from there, carefully.

6. Ensure the fuel system is completely clean and works correctly. Fuel pump, carbs, fuel lines and connections.

7. To do a general test of the system. Start it and let it idle where it won't die on you (advance throttle in warm up). Pull each plug wire off the engine, with engine in gear. What you want is an almost even firing of the cylinders. If you find one or two that are off you will need to go through the list again or start looking for an airleak in the block somewhere.

These are tricky and very demanding engines to get a good idle . I sent two out of the shop this week that I spent a lot of time on to get right. I never liked these old crossflows!

Here is a usefull tip, that I find quite frequently. If it is in saltwater, check the idle as I pointed out before. Pull one lead off at a time. Listen...does it drop when you pull the wire? If not or if it has results which are not the same every time, check the leads coming from the power pack to the coils. Pull them off and inspect them. Corrosion is a problem on these and will make the engine idle poorly and in some cases run poorly. If they are corroded. Clean the coil post. Install a new connector on each wire. That has been a problem on each of the engines I repaired this week.

 

[multimech]

Re: How to adjust idle speed on a 1984 Hp Evinrude?

Another point that may or may not apply. Make sure the jet sizes are correct for your engine. If you bought it second hand, anything could have been done to it so you need a base starting point. You will find the jet sizes in the shop manual.

 

[Fisherman_7]

Re: How to adjust idle speed on a 1984 Hp Evinrude?

Motor runs great on LOW speed, Medium speed, and HIGH speed. No problems there at all. Its just when I come back to the launch ramp, and put it to neutral position the idle has dropped to low. The engine dies before I can kick it back into forward. This is the orginal engine I got when I bought the boat. Im thinking carbarator rebuild replacement kits will fix the problem or to adjust the idle speed somehow. Carbarators have never been touched. Motor has not been in Saltwater ever. What do you think?

 

[emdsapmgr]

Re: How to adjust idle speed on a 1984 Hp Evinrude?

The engine's idle is adjusted by the big screw on the spark advance lever. The timing is what determines the idle rpm's, not a carb adjustment. Set the idle to 650-700 rpm's when the boat is floating normally in the lake-in forward gear. Set the idle for correct rpm's not any idle timing number. If it just won't idle properly after making this adjustment, you may need to consider cleaning the idle passages inside the carbs-a teardown and complete internal carb cleaning process. Once you crack the throttle even a little, other jets feed fuel to the engine and you indicated it runs fine at all other rpm's. Probably a carb issue.

 

[Fisherman_7]

Re: How to adjust idle speed on a 1984 Hp Evinrude?

Thank You so much. Your answer hit the nail on the head. These are the original carbarators on this engine, and has never been clean or touched to my knowledge. I have ordered new kits for the carbs, and decided to take them off for a good cleaning. I do understand what your saying where the idle adjustment screw is located now and how to perform that task. I won't have a piece of mind though unless I clean those carbarators and put new kits in them. Thanks again for your expertice on my problem.