1998 115hp evinrude 90? cross flow

[dieselcat]

Motor is stalling under a load,runs fine in neutral revs up fine in neutral but soon as I put it in gear and throttle up it falls on its face and dies..
I rebuilt the carbs previously,put new plugs in it already

 

[racerone]

Compression test is the # 1 step to do.

 

[interalian]

These will idle fine and rev in neutral when down a cylinder. Need to check compression and spark - spark should jump 7/16" using a spark tester. Alternatively, attach a timing light to each cylinder in sequence to check if you're getting spark there.

 

[dieselcat]

Compression and spark all good. I'm assuming the stator is good cause motor starts,runs,and charges so I'm leaning towards trigger or power pack. Any info on testing these 2 components

 

[emdsapmgr]

Not sure just what you are asking... When you say the spark is "all good" that means you have good spark on all 4 cyls. If so, why are you now concerned about the power pack or trigger? If you are diagnosing the running issue you describe- you need to determine if the engine is dropping a cyl. Keep in mind the engine will usually run fine when cold, even with a weak ignition component. When the engine warms up, it begins to affect the weak ignition component. So when testing these ignition components, stator, timer base and power pack-be sure the engine is warmed up to normal operating temps.

 

[dieselcat]

As far as the power pack goes I wasn't sure if it controlled something other than the spark and motor runs the same cold or warm doesn't change. I ran the motor in a water tank last night and when I would throttle up everything was perfect ran like it should soon as I put it on the water it started acting up. It was my dad's boat and I inherited it after he had passed away it sat for 5 years before I got it so I have done all of the proper maintenance to ensure everything was good so I am guessing something electronic probably gave out since it had been sitting so long. When replacing a timer base or power pack does the motor Have to have the timing reset?

 

[BrettNC]

If compression and spark are good, then this can be caused by too lean of a mixture at idle. Check for gasket leaks, water in cylinders, carbs.

 

[BrettNC]

Check timing and idle speed as well. Do a link and synch procedure to rule out.

 

[dieselcat]

Ran fine a week ago that's why I'm leaning towards an electrical component going out

 

[interalian]

When you say "stalling under a load", do you mean the engine quits or that it loses power/runs rough? And does it feel like the engine is struggling for speed?

I had a coil fail on my crossflow 140 and it's amazing how much less power you have when down just one cylinder, and amazing how rough it ran on 3. The failure happened after running fine for hours. I diagnosed using a timing light and confirmed it was a coil by swapping spark plug leads AND the leads from the power pack.

 

[dieselcat]

By stalling I mean it runs fine at idle and as soon as I throttle it up it dies...like its not advancing the timing correctly. I'm getting 1000-1500 rpm at best and doesn't matter if I give it 1/4 throttle or 3/4 throttle it won't build rpm and anything over 3/4 kills the motor like it's flooding it out

 

[flyingscott]

When did you rebuild the carbs was it right before this problem?
Was a link and sync done?
When was the last compression test done?
Did you do a spark test.

 

[dieselcat]

You guys all keep asking me the same questions,the motor ran fine Saturday eve then Sunday I put in the water and it stalls as stated above. Less then 2 weeks ago I went through the carbs,put all new fuel line and changed the fuel water separator. Took boat out on the water and starter quit,I rebuilt the starter myself took boat back out and now it stalls/dies when throttling up

 

[interalian]

Is it possible the timer base linkage has disconnected? Top of the throttle arm has a rod that links to the timer base and moves it with throttle position. At idle it's toward the rear of the engine, and by half to 2/3 throttle it should be stopped against the timing set screw with rubber tip.

 

[dieselcat]

All linkages are in proper place and working as should

 

[dieselcat]

Anyone have the testing procedure for timing base/trigger? I have recently moved and can not find my manual for motor.

 

[BrettNC]

I misread your post a little bit. I thought you saying that the motor died when put in gear. Stalling on advancing throttle is a classic lean condition. Make sure that you don't have any leaking gaskets. Hook up a timing light to check timing as the throttle advances.