97 evinrude 115 blew up! What caused it? Help

[jones56]

I have a 97 hydra sport with a 97 evinrude 115 on it. Me and my cousin was fishing a tournament Saturday and running up the lake at wide open throttle. Then it happened! Motor immediately bogs,knocks and shuts off! It starts back but is running bad. Get it home run a compression check and # 4 had only 30 psi compression. Tore it apart today and found that #4 top ring had broken and and ruined cylinder, piston and head. Why did this happen???? I know for sure the oil/ gas mixture was good because the VRO is removed and I mix it every time I use it. Looking for answers because I don't want this to happen ever again. How much does this cost to get fixed?

Thanks guys in advance

 

[jones56]

Re: 97 evinrude 115 blew up! What caused it? Help

It is a 115SPL if it matters

 

[Fleetwin]

Re: 97 evinrude 115 blew up! What caused it? Help

Most likely a clogged carb jet caused that cylindsr to run lean.

 

[emdsapmgr]

Re: 97 evinrude 115 blew up! What caused it? Help

This must be a crossflow. Agree. Pull the carb apart that feeds that cylinder. Esp- visually check the high speed jet (that feeds that bad cylinder) for debris. If the jet is clear, then it could be an overheat. Pull the head off and check the 2 rubber water diverters on that side of the block. Make sure they are still correctly positioned to direct the water flow in a circular fashion around the cylinder. And that there is no debris restricting water flow. You may need to pull the head cover off the head to check those water passages also. It's possible to get an internal overheat on one cyl and not have a hot horn from the control box.

 

[bob johnson]

Re: 97 evinrude 115 blew up! What caused it? Help

If it over heated, shouldnt the motor have gone into SLOW mode???

sounds like it didnt...it blew at speed!!

detonation, carbon build up, a lean condition should have caused so hot temps...but it also bring the fact there isnt enough oil in that cylinder as well

thats why i have TWO temp guages , one for each head...AS WELL AS a water pressure gauge. if I start to get high temps and i still have the same water pressure...thats a sign something other than water flow it at hand...

bob

 

[jones56]

Re: 97 evinrude 115 blew up! What caused it? Help

No notice at all. I had run the boat all morning and went to move across lake and I was wide open for about 2 minutes running great then the noise and loss of power was immediate Water pressure was 18-20 ,no beeper and no loss of power Pior to blowing