What Caused the Meltdown

[rdav13]

92 Evinrude 60 hp, TE60TLENE, was running fine until the last trip out. Cruising @ 5800 rpm, the engine starting loosing power until it slowed and quit. No alarm For Temp or VRO. Upon initial restart engine was seized but after cooling, the starter fired it up running badly. Limped back to the trailer and drug it home.<br /> No compression in the #2 Cyl... Pulled head and #2 cyl scored badly and part of top of piston near exhaust port melted. I’ve ordered a reman powerhead from Iboats and now need to determine the cause of the problem.<br /> I've heard of OMC service bulletins concerning overheating with this model of engine and I don't believe any have been performed on this engine (purchased used). What do I look for as to determine the actual cause of my problem? <br /><br />Kudos to Iboats for providing this great forum and to all the knowledgeable posters who share their wisdom for the benefit of others.

 

[rdav13]

Re: What Caused the Meltdown

Sorry for not leaving my name, Iwas so concerned with getting all my information together for everyone.<br /><br />Thanks, Roy

 

[Dhadley]

Re: What Caused the Meltdown

Welcome!<br /><br />What spark plugs were you using? What grade fuel?

 

[rdav13]

Re: What Caused the Meltdown

Plugs were Autolites, I'll have to check the number. I've been running 92 octane fuel<br /><br />Roy

 

[stairliftoheaven]

Re: What Caused the Meltdown

had EXACTLY same problem with my '85 60hp same cylinder, same damage to piston, also ring got caught in combustion chamber and made mincemeat of the cylinder head. Not really established the cause yet. Rebuilding at the moment but will use correct plugs and rebuild carbs properly before attemptin to start it.<br />good luck and if u find anything out, would u mind sharing the info with me lol<br />thanks<br />Chris

 

[Dhadley]

Re: What Caused the Meltdown

Ok, running those plugs and fuel creats more combustion heat than the motor can handle, obviously. There are two directions you can go.<br /><br />One is to run the Champion plugs and 87 octane fuel as recommended. <br /><br />The other is, if you are still going to run that fuel and those plugs -- richen up the carbs to help cool down the combustion temps. I would go a couple sizes richer on the mid and hi jets. Especially on the middle cylinder. Thats the hottest one on that motor as you found out.<br /><br />Either way I would, if it were mine, richen up the mid range jets by 1 or 2 numbers especially on the middle cylinder. Remember if your carbs use air bleed in the mid range, you need to go smaller to go richer.<br /><br />Good luck!

 

[rdav13]

Re: What Caused the Meltdown

OK the plugs in the engine were autolite # 2634.<br />My clymer manual says champion QL77JC4, that is what I am planning to go back with. If 87 is the recomended octane I will stick with that also. I thought I was being kind to the engine using premium fuel. I'm not a performance nut, just would like the motor to last. <br /><br />I haven't been inside the carbs yet but I do have kits ordered. In this part of Idaho everythig has to be ordered. If it would be a benifit I will order larger jets once I get inside and see what is in there now. You say richen up the mid range jets, will my carbs have a mid and high speed jet? Like I said I haven't been inside one yet or even studied that section of the manual.

 

[stairliftoheaven]

Re: What Caused the Meltdown

Dhadley, I take it the way to adjust mixture is to change size of jets??? there doesn't appear to be any adjustment screws on my carbs. my engine is 2cylinder, was bottom one that melted.<br />thanks

 

[Dhadley]

Re: What Caused the Meltdown

Yes, there are mid and hi jets. Just remember, on air bleeds -- ya gotta go smaller to go richer. Hi speed jets regulate fuel but on some carbs, the low and mid range jets meter air.

 

[rdav13]

Re: What Caused the Meltdown

With the correct Champion plugs and 87 octane fuel, do I just richen the mid range jet or the mid and high jets?

 

[rboat99]

Re: What Caused the Meltdown

Not to hijack this post, but Dhadley I have a strange situation with my carbs. <br /><br />You did hijack the poat. Please start your own.

 

[gkerfoot]

Re: What Caused the Meltdown

Please do not hijack anothers post. Please start your own in the proper catagory.

 

[rboat99]

Re: What Caused the Meltdown

sorry guys, it's good to see that the post police are out in force.