1996 28spl violent shaking

Mthirsch14

Seaman Apprentice
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Jan 26, 2019
Messages
46
Finally got all the kinks worked out after having electrical issues and took her out on the lake. Everything seemed good got up to plane and was cruising for maybe 2minutes then when I decided to pull back and slow down I was at maybe 1/4 throttle and the engine started violently shaking side to side. I ended up turning the key off to prevent damage so I’m unsure if it would have died on its own or stopped shaking once I slowed down more. I check both plugs and there was a good spark. Even tried starter fluid but nothing I did got any combustion. Any ideas on what would cause it to shake very hard side to side? And why it won’t fire when i have spark and fuel?
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
36,033
Broken motor mounts ??-----Check for a sheared flywheel key first..
 

Mthirsch14

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Jan 26, 2019
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The mounts have some play in them and the bolts are too rusted to try to tighten, but it’s always been that way even when it was running good before the electrical problems. I haven’t pulled the flywheel, I will do that tomorrow, but turning it by hand it’s still tight feels like it has the same compression
 

Mthirsch14

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Jan 26, 2019
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Flywheel key is intact, compression is about 130-135 on both cylinders, fuel pump is working, strong spark on both cylinders checked with an open air gap tester but it just won’t fire. What am I missing? I tried messing with the carb and choke opening and closing it to give it more air but nothing is working. I tried starter fluid in the carb and straight into the cylinder but nothing. Any ideas?
 

juno pierrat

Petty Officer 1st Class
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Dec 14, 2013
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355
ok, open air gap tester set what setting, 7/16?
go easy on the starter fluid, better to use pre mix gas
 

kbait

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Nov 13, 2007
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2,446
If you have spark..and at right time (should be with intact flywheel key), proper compression, and it won’t fire w/fuel in the cylinders, it must be flooded (assuming spark plugs good). Unplug fuel line from tank, pull the plugs out, hook up spark tester and spin the motor over for a while to clear any excess fuel. Re-install plugs and try to start (fuel hose disconnected). If it runs for a bit and dies, you were VERY flooded. If it doesn’t fire, hook up hose, prime carb and try to start w/choke. If still no fire, squirt a bit of fuel in carb throat and see if it pops.. report back w/results.
 

racerone

Supreme Mariner
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Dec 28, 2013
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36,033
Checked impeller / overheating ?------Reed valves ?----Checked for gear damage .------Drained gear oil ?------Lower crank seal ?
 

oldboat1

Fleet Admiral
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Apr 3, 2002
Messages
9,598
Make sure the jet at the bottom of the carb is clear. Run a small wire through it, followed by a spray of carb cleaner. Reset the idle needle (air mix). Initial setting on older motors is 1 1/2 open from lightly seated. Yours might be about 3 turns.
 

oldboat1

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^^point is good. Magneto might be capable of producing strong spark, but plugs or plug gap could be an issue.
 

Mthirsch14

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Jan 26, 2019
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I haven’t had time to check the carb or the lower unit hopefully tomorrow afternoon I will be able too. The spark plugs are brand new only about an hour of running time on. I also checked them by grounding them to the block and I get a strong blue spark.
 

Bosunsmate

Admiral
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Apr 7, 2012
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6,129
Did you check flywheel key by taking the whole flywheel off?
Did you try moving the flywheel side to side by hand to check upper bearing is ok?
Failed upper seal perhaps
 

Mthirsch14

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Jan 26, 2019
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Okay so I lied about the flywheel. I just assumed it was okay because I had spark I finally had time to check it today and it’s not good. The pin in completely sheered off and there is a big chip missing from a magnet. Why did this happen? Was the nut not torqued correctly?I’ve put about $600 into this boat (1996 14ft Carolina skiff 1996 evinrude 28spl e28esledr)in the last couple months. Is it worth it to fix it? I assume I need a new flywheel which isn’t cheap, and either a new key or a whole new crankshaft? Please somebody help you guys have been great!
 

Mthirsch14

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Mthirsch14

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oldboat1

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Done running it with that flywheel, IMO.

I would look for a used on on Ebay or at a local boneyard. Look at it carefully for condition and match. I believe I see some debris from shearing on the shaft, but that will clean up -- note the end thread on the shaft is gouged. Check the nut -- both may still be usable. What’s left of the key can be popped out of the machined slot using a small screwdriver. The shaft can be cleaned up with a shop rag and valve grinding compound, then cleaned with acetate (no oils or lubrication).

The bevelled shaft and flywheel grip the flywheel in place, insured by proper nut torque. The torque was likely too light on yours. Torque is likely 102 foot lbs, but check on that. Use an oem flywheel key.
 
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