What does it take to burn pistons on a 500EFI
#11
21 and 42 footers
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Built 9.7 comp 540's from 500EFI's . Injectors had been upgraded to accomadate Prochargers that we were removing. Turns out 2 of the injectors fired up to about 3/4 throttle but would shut down at WOT. These 2 cylinders recieved NO fuel and detonated and blew the pistons apart with 2 hours of running the new motors. Once we rebuilt that one test runs showed the 3 month old ETHANOL fuel had deteriorated to the point is was NOT 93 anymore.
As stated above, the failure of the motor was technically my fault. Bad injectors, bad fuel. A stock 500EFI that has been put together properly should run 5,000 rpms until you run out of gas with no issues.
BTW: The knock sensor is what alerted us to the fuel problem after rebuilding the motor, I had the computer programer here on the boat for test runs once we had it back together.
As stated above, the failure of the motor was technically my fault. Bad injectors, bad fuel. A stock 500EFI that has been put together properly should run 5,000 rpms until you run out of gas with no issues.
BTW: The knock sensor is what alerted us to the fuel problem after rebuilding the motor, I had the computer programer here on the boat for test runs once we had it back together.
#12
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#13
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Sold a guy a motor 2 years ago and it ended up blowing up recently.
They tried to blame me, # 2 rod bearing had failed.
I used my fiberoptic borescope and found out that the piston expanded due to high heat and that was why the bearing damage occurred. Motor either leaned out or simply had not enough water flow. I showed his mechanic the inside of the cylinder and the up and down lines from the piston grabbing the cylinder wall. Turns out that the marina did not install the raw water pump I gave them with the 4 " pulley, and ran the 6" one that was in the boat that was underdriving the pump, as well as not installing the thru hull fitting and strainer. I don't know how to deal with this, I like these guys , and I haven't been able to proove very much to them because everything gets screwed up. This motor was 9.4 - 1 and also needed 93 octane.
The owner of the yard is pissed because I can't be there and I did not do the installation , or even be there to overlook any potential reasons for my beautiful motor to go bad.
I'm going there in the am and need to prepare myself for whatever BS I may encounter. Thanks, BBB
They tried to blame me, # 2 rod bearing had failed.
I used my fiberoptic borescope and found out that the piston expanded due to high heat and that was why the bearing damage occurred. Motor either leaned out or simply had not enough water flow. I showed his mechanic the inside of the cylinder and the up and down lines from the piston grabbing the cylinder wall. Turns out that the marina did not install the raw water pump I gave them with the 4 " pulley, and ran the 6" one that was in the boat that was underdriving the pump, as well as not installing the thru hull fitting and strainer. I don't know how to deal with this, I like these guys , and I haven't been able to proove very much to them because everything gets screwed up. This motor was 9.4 - 1 and also needed 93 octane.
The owner of the yard is pissed because I can't be there and I did not do the installation , or even be there to overlook any potential reasons for my beautiful motor to go bad.
I'm going there in the am and need to prepare myself for whatever BS I may encounter. Thanks, BBB
#16
21 and 42 footers
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I sent all 16 injectors to be tested and marked then for MY reference only. The tester was able to tell me which 2 pistons were ruined after testing them. (I never told him which cylinders or in which motor the problem occured)
#17
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respectfully disagree. if motor was built properly to start with , then pinging a hole in a piston or two is strictly a function of someone screwing up.
if it had bad gas due to age ( low octane as mentioned above) then its the guys fault that was dumb enough to try to run the boat w/ old gas...
same w/ the timing and injectors or jets or anything else...
nothing is plug and play when you are talking about high hp big v-8s ... its your job to make sure all that stuff is correct before you launch. if you are going to only run the boat a few hours a year then you solve the gas problem by not filling it full of gas and then letting it sit around... you keep absolute min fuel in it and fuel it fresh each time you go out and if its going to sit for 6 months then you drain it and make sure you run some marvel mystery oil thru the injectors and pumps...etc etc etc...
nothing " just happens"
if it had bad gas due to age ( low octane as mentioned above) then its the guys fault that was dumb enough to try to run the boat w/ old gas...
same w/ the timing and injectors or jets or anything else...
nothing is plug and play when you are talking about high hp big v-8s ... its your job to make sure all that stuff is correct before you launch. if you are going to only run the boat a few hours a year then you solve the gas problem by not filling it full of gas and then letting it sit around... you keep absolute min fuel in it and fuel it fresh each time you go out and if its going to sit for 6 months then you drain it and make sure you run some marvel mystery oil thru the injectors and pumps...etc etc etc...
nothing " just happens"
Just My .02
#18
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500efi's are generally tough as nails. I put 414 hrs on mine before pulling it ( bottom end ) apart. NOT easy hours either. I have run the boat 30 miles at 5200rpm on several occasions, dozens of WOT poker runs and generally toture tested the sucker all on 87 octane and never hurt the bottom end. Just wore it out.
#20
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Who did you send the injectors to Russ? I need to get mine in the mail.