Wide Open Throttle one second, dead the next after a rapid steady decline in RPMS. I can't tell if my issue is the result of oil/fuel starve or overheat but after getting home, I confirmed 120 PSI bottom cyl, 110 Middle cyl, and 30 top cyl. I took off the head and here is what I found. Does this look like an overheat situation to you guys (Paging TK Walker.... Paging TK Walker...) or an oil starvation situation? Trying to decide whether to rebuild or get a reman powerhead. I'm not afraid to rebuild it myself I just don't know if it will be worth my time and effort and money or if I can get it done in less than a week compared to a reman powerhead off ebay. Any thoughts? The model # is 90ETLJ. The overheat alarm was disconnected a couple years ago because it was going off all the time as a false alarm. STUPID STUPID STUPID.
It did, after sitting in the water for a little while, start back up but ran TERRIBLY. I used the trolling motor to get home and barely had enough battery.
It does look to me like the cyl isn't scored so much as the piston melted and welded itself to the cyl wall. It looks like metal on top of the cyl wall vs. a groove into the cyl material itself.
What all would be involved in this? Would I rebuild just the top hole or all 3? (PAGING TK WALKER) A reman powerhead on ebay is 1k - 1.3k based on a quick 30 second search. I haven't dug in any deeper yet.
Somebody tell me what to do!!!! (TK WALKER) Please!!!! I am determined to have this fixed before the end of the day Saturday 4/16. I have a 3 day fishing trip planned beginning Sunday. Any and all advice is welcomed. Thank You! Pix attached.
Jk, Your diagnosis is pretty much right on ... Questions: (1) What do the other Cyl's look like?? (2) What is included in the Re-manufactured Power Head ... If it is everything and all you have to do is add the fuel system and starter, etc. then The new power head would be the way to go ... This way you have new pistons, rings, etc. also does this include New gaskets, (Base, Intake, etc.)
You are looking at a lot of work with little time to repair you PH. You will have to re sleeve or bore, New piston and rings (over size if you bore) Complete gasket set (Not cheap)..
Since there was no signs of any damage to the other cyl's and pistons (assuming) I don't think overheating would be the problem .. Need to check the top cyl. fuel system and make sure the injector and lines has no restrictions. Possible starvation and leaned out. Another possibility is that it broke a ring ... Let me talk to some people tomorrow and I will get back with you... But a new power head seems the way to go... <'TK><
PS. I don't have my ID number book in front of me ... I am assuming that it is Fuel Injected.
Oil starvation by some account, manufactured power head is the way to go. As TK mentioned the gaskets are premium, replace the oil level indicator/switch in the oil tank to stop the false alarm.
*While your at it...call Hydro-Tec and add the tuner exhaust, Hi-Po head, check/block and rebuild the reed block and rebuild/re-jet the carbs (I believe all 90 and below are carburated) to account for the new fuel requirements. All that if you would like to add about 10/15 HP.
When I built my last Hi-Po motor it was a Yami 75hp tuned to 90hp+ and I could easily out run aluminum rigs with 115hp...sure wish I had that motor back.
Jk, Your diagnosis is pretty much right on ... Questions: (1) What do the other Cyl's look like?? (2) What is included in the Re-manufactured Power Head ... If it is everything and all you have to do is add the fuel system and starter, etc. then The new power head would be the way to go ... This way you have new pistons, rings, etc. also does this include New gaskets, (Base, Intake, etc.)
You are looking at a lot of work with little time to repair you PH. You will have to re sleeve or bore, New piston and rings (over size if you bore) Complete gasket set (Not cheap)..
Since there was no signs of any damage to the other cyl's and pistons (assuming) I don't think overheating would be the problem .. Need to check the top cyl. fuel system and make sure the injector and lines has no restrictions. Possible starvation and leaned out. Another possibility is that it broke a ring ... Let me talk to some people tomorrow and I will get back with you... But a new power head seems the way to go... <'TK><
PS. I don't have my ID number book in front of me ... I am assuming that it is Fuel Injected.
I Thank you for the quick replies! This is a 1986 90 hp yamaha carburetor motor TK. I don't see any damage to the middle or bottom cyls but I will finish the teardown today for more info. It looks like I could get a gasket set for about 100$ or a rebuild kit with persons and gaskets for about $450 or if I wanted to gamble I could get the gasket kit one piston and rings for about 225. Here are the two powerheads from ebay. One is reman the other is used. I'm not really excited about either but bolting one on would sure be nice.
Btw... the top cylinder walls are dry compared to the bottom two still wet with fuel and oil. I agree it looks like oil fuel starve but when I removed the cowl she was pretty warm to the touch up top by the stat hooks housing. However... Pete stream was as solid as ever even when just cranking it with the starter.
If I decide to rebuild mine do you guys know of a machine shop that could do the machine work quickly? I could get the parts to someone this afternoon or tomorrow. Could anyone get them back to me in a day or two? Also... how much should I expect for the machine work bill?
Thanks again. I apologize yet again for hijacking the fishing forum. Feels free to move 've this thread if needed.
Just a note...chances are your main and rod bearings are trashed as well. I suggest you get a re-man power head and go from there. Resizing the crank will require a significant amount of time, money and scheduling in a local machine shop if they will do it.
What oil do you use???
*Only recommended machine shops in 100 miles: http://huntsvilleengines.com/
"Eddies" if he is still in business in Springfield, Tn. if he will accept the work (race engine shop)
Just a note...chances are your main and rod bearings are trashed as well. I suggest you get a re-man power head and go from there. Resizing the crank will require a significant amount of time, money and scheduling in a local machine shop if they will do it.
What oil do you use???
*Only recommended machine shops in 100 miles: http://huntsvilleengines.com/
"Eddies" if he is still in business in Springfield, Tn. if he will accept the work (race engine shop)
JK, Notorious and I concur. You would be money ahead for a reman. PH. I don't think you have the time to collect the upgrade parts that Notorious mentioned but it would be sweet!
Note: Yamaha really likes their stuff $$ if you can get a good reman PH for the money you mentioned that sounds cheap. Good Luck ... <'TK><
TK - Do you see anything in these photos that would scare you out of re-building this? Clearly the # 1 CYL and Piston are toast. Do you see anything in the crank and crank bearing pix that concern you?
TK - Do you see anything in these photos that would scare you out of re-building this? Clearly the # 1 CYL and Piston are toast. Do you see anything in the crank and crank bearing pix that concern you?
JK, It is hard for me to trouble shoot or make a diagnosis/Analysis by looking at pic's... Folks call me all the time and want me to trouble shoot over the phone ... For me it it is like drinking a Heineken, I have to hold it feel it, smell it and put it against my cheek...
What does the color of the #1 crank journal look like is it discolored (Black ?) since your pic's aren't ID'ed it is hard to determine ... I take it you are contemplating rebuilding ... I think you are capable, but you won't meet your dead line ... <'TK><
What oil do you use? And does it mix or do you premix? Looks like that hole went lean. You may still find pics of mine that blew a hole the size of a 1/2 dollar in the #2 piston, so I feel your pain.... Good luck and hope you get it done in time.
I bought a used powerhead that will arrive today. I still plan to re-build mine but this will get me on the water this weekend (I HOPE!) without rushing through the re-build and regretting it. I'll sell one of the two after I rebuild mine.
After taking my motor to a few "experts" the consensus is the failure was not due to oil but due to a lean condition in the top cyl causing detonation/pre-ignition and internal overheat. No signs of water pump or cooling system failure.
I'm going to start running high octane fuel and non-Wal-Mart oil for cheap insurance.
I bought a used powerhead that will arrive today. I still plan to re-build mine but this will get me on the water this weekend (I HOPE!) without rushing through the re-build and regretting it. I'll sell one of the two after I rebuild mine.
After taking my motor to a few "experts" the consensus is the failure was not due to oil but due to a lean condition in the top cyl causing detonation/pre-ignition and internal overheat. No signs of water pump or cooling system failure.
I'm going to start running high octane fuel and non-Wal-Mart oil for cheap insurance.
I am certainly no mechanic, however, if a lack of fuel/oil mixture in the cylinder caused the problem the brand of oil would not matter.
Blown Outboard! CRAPPPPPPPPPPPPPPPPPPPPPPPPP
Uummmmm <'TK><
Replace Powerhead <'TK><
