2000 F115 Four Stroke Questions

[Bassgod]

I am working on this motor and have 2 questions:
1. What size allen/hex wrnech is required to remove the oil drain plug?
2. I got some very strange compression readings on this 4cyl (148, 148, 137, 180) I have never seen one so spread out, but I don't service to many Yamaha's. How bad is this, if at all?

Thanks Motor Gods.

 

[rodbolt]

Re: 2000 F115 Four Stroke Questions

best I remember its a 14mm plug directly under the exhaust relief, however I never use it, simply suck it out the dipstick area. if you use it make sure the sealing washer is not dropped.
the drain is covered by a rubber shroud but its there.
and that is why I wont do a compresion test on a 4 stroke yamaha, its way to much faster and more accurate to do a cylinder leak down test.
when you did the compression test what method did you use to disable the fuel system ?

 

[Bassgod]

Re: 2000 F115 Four Stroke Questions

I only disabled the kill switch. Did I do a bad thing? Is it easy to recover from?
Thanks for the help.

 

[rodbolt]

Re: 2000 F115 Four Stroke Questions

pulling the kill switch will disable the EFI system. thats a good thing.
you should have gotten an audible alarm when cranking with the kill switch removed,if not add that to the list of stuff to check.
one day I will post a funny story about EFI motors and compression testers, how about a little fire scarecrow .

 

[Bassgod]

Re: 2000 F115 Four Stroke Questions

I didn't get any alarms. I got it all done and sent it home. This motor had 6 quarts of oil in it, when it supposed to only have 4.8! Could that cause a high compression reading on the bottom cylinder? The bottom plug was much wetter than the top 3.

 

[rodbolt]

Re: 2000 F115 Four Stroke Questions

I dont think so, thats why a leakdown test is critical.
if you did not get an alarm while cranking it with the kill lanyard removed the motor is still broke and may need further testing of the alarm system,preferably before it pukes cause the operator did not know it was overheating.