98' Evinrude E115TSLECM Crossflow Questions

[kraw2]

Hello,

I have this engine on the 170 I restored and have a few questions. I haven't had an older 2 stroke running pre-mix in many years.

When starting the engine is hard to start when cold. Is this normal? I had a 1980 70 Evinrude that would start just by touching the key one time.

The engine is just now broken in and the tach doesn't work correctly. At idle it seems fine. Any higher than 2000 it pegs the needle. Faria 7000 RPM tach set on pole 12. Do I need a voltage regulator for this tach?

After the engine is warmed at idle it "pops" about every 15 seconds. It pops, stutters, and blows out a puff of smoke, then back to normal until it does it again. Is this also normal. The engine runs very well at anything above idle. I don't know the RPM numbers yet b/c of the tach problem. The mix is still at 25:1 until the rest of the 25 gallons runs out.

Thank again..!!

[fitz73222]

Hey Kraw,

I'm waiting till I get home from work for this one...This is one of my favorites if the carbs have been rebuilt!

[kraw2]

The tach is now working correctly. Wrong setting.

[wingtime]

Would what he describes be called a sneeze?

[fitz73222]

Ok Kraw,

Tell me about the rebuild. Did you do it yourself or you had someone do it? The carbs were completely disassembled and cleaned? The engine was set up and timed according to factory specs. There are a lot of things this can be since it was just rebuilt so we can start from the basics and work back into the block. I checked out the parts breakdown for your model to make sure I understand which design she is and she is as you mentioned the basic crossflow OMC.

So lets begin...

[kraw2]

The power head was rebuilt at a local machine shop that does rebuilds all types of engines. 3 year warranty. They are the rebuilder for the dealers in our area.

The carbs were rebuilt compltetly and the timing has been set and checked on the water.

When it's idiling it will "sneeze" "pop" or whatever for one stroke and go back normal. We need to run it more and see how it does. After warmed up it starts like a new motor should. No choke and a flick of the key.

Everything may be perfect. I'm not used to having an old motor again..!!

[kraw2]

I have found that there are no outside air adjustment on these carbs. The mechanic told me that at idle the fuel drips thru a small hole to distribute the fuel. This sounds different to me??

[fitz73222]

Lets start with basic diagnosis. You have at least one or more lean cylinders that are causing the cough. Your engine has non adjustable low speed jets. The idle air is delivered through a fixed orifice that delivers the adequate air to run and is mixed with gasoline in the mixing chamber that is located under the flat plates on top of each double barrel carb. So lets figure out which cylinder is lean. There are two ways to do this. The first is to remove the air box (attenuator) cover to expose the throttle bores. With the engine running, cup your hand over each of the four bores and wait for a response. Don't completely block the openings. the goal is to create a rich environment by artificially starving air and making her go a little rich from a air/gas standpoint. Since you have dual bore carbs you have to "block off" each venturi and see if the engine speeds up or bogs down. If she bogs down for this test that's OK if she speeds up you found the lean cylinder because you created a more fuel rich environment that she likes and will temporarily run better. The other way to check this (engine running) is to pull a spark plug wire off with a pair of fuse puller pliers and see if the cough goes away when you have no fire going to that cylinder. She'll run like crap but the cough should go away. Try this test and see if we can determine which cylinder is rebelling and the we can move from there. Sometimes while running with the air box removed and she coughs she will belch a little fuel back out the problem cylinder out through the carb.

[kraw2]

Will do..

Thank you for the details. The certified mechanic friend of mine said sometimes it's a simple as slighly enlarging the low speed opening.

Per your instructions a proper running warmed up cross flow engine should not "cough" at all in idle conditions. Correct..?

[fitz73222]

It really should not cough at all except maybe when ice cold but bumping the keyswitch inward (enrichner) should correct the cough pretty quickly and she should run smoothly without a cough. 1998 was an interesting year for the outboard industry. It was the first year of the (CARB) California Air Resources Board emissions standards for outboards and for the first time 2 cycle outboards became regulated. This meant that under the emission restrictions, outboards had to run with a stricter emission requirement and the industry responded with leaner running engines. These idle quality issues surfaced quickly and some engines simply coughed at idle. We had a number of new engines out of the box that had the idle cough. To me, this was totally unacceptable but difficult to overcome. The carburetor castings had been redesigned to run leaner and the minute passages to control idle fuel ratios were fixed. OMC's were a challenge because the idle mixture was non adjustable. Merc's still had adjustable mixture screws that allowed you to deal with the cough but they all did it. We ultimately were able to manipulate the jetting in the carbs and play with timing to get rid of it. So your engine builder is on the right path if this cough persists.

[akbridge]

My 90 when linked and synced does not sneeze on the water.  It will sneeze on the muffs when flushing.  But that is kind of normal as it is lean when not in the water.  Mine can be moody to start when cold.  But after warming up it is quick to start.  By the way I have a 1992 90.

[kraw2]

Yes it is only sneezing on the muffs...

[fitz73222]

Yes it is only sneezing on the muffs...

Well that's a  seahorse of another color. I thought you had the issue in the water. Akbridge is correct; they do run leaner on the muffs. So it may not be worth exploratory surgery if you can live with the embarrassment of you neighbors listening to your engine running with whooping cough! LOL.

[ospreymvh]

Since the sneezing issue has been addressed, there’s the cold starting issue. I’m given to understand that engine was notorious for being difficult to cold start and until I figured out the ‘code’ on my ’98 115 crossflow, mine was no different. At least for me, after the bulb is hard, slight throttle bypass, push the primer and hold while cranking- those engines cold like the gas…..holding the primer while cranking should allow the diaphragm pump to spit the additional demain into the chamber…..worked for me!