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Anyone with a 300x manual that covers 2001, S/N OT235158, what's the manual call out on compression ??????? I bought a new Merc manual and I've already found lots of errors besides the one page revision sheet they put in for all the corrections and I think this is just another one, they list compression @ 110-115 :eek::eek:.
Thx,
300 ProMax/Super Magnum shop manual (pre X models) specs compression @ 120-130 psi.
Compression to be checked w/ throttle plates @ WOT.
Doesn't spec hot or cold.
having the same
the x motor compression will be different then the promax/super mag. what numbers are you coming up w/ gary?
Charlie,Quote:
Originally Posted by mrcrsr
I haven't done a compression check yet, although I will this weekend. Reason for asking is as I was reading the manual the other night, it quoted compression for the Merc 300x at 110-115 psi for my year & S/N motor, I just thought that to be way to low. That's basically 225/250 compression. I was expecting to see 125-130 compression for the 2001 300x, I'm I way off here ?????????
Charlie,
UPDATE:
I got home early today and ran the compression test. Manual says 110-115 psi on my 300x and I'll have to say the manual is totally wrong. On a cold motor I ran all 6 ranging from 145-149 psi. So much for a $90 manual to guide you through your motor......... :rolleyes::rolleyes:
that sounds better gary, i expected to see anywhere from 135 to 145(but wasn't sure), the key thing is no more then 10% variance(and i like to see less then that)
Charlie,
The readings are probably a tad high because I did put some oil in each cylinder prior to testing, but never the less there all checking close to each other. I did ask Merc in an email why the manual stated 110-115 psi and there reply was quote:
Re: 2001 Mercury Pro Max 300X
Thank you for your e-mail regarding your 2001 Mercury Pro Max 300X motor, serial # 0T235158. We appreciate the opportunity to respond to your concerns.
The specifications in the book are correct for a new motor. As the motor breaks in (about 30 hrs run time), and the rings start to set, you can expect to see around 130+ psi for compression.
We hope this information is helpful to you. Should you have any further questions or concerns, please contact our Customer Service department at 920-929-5040 between the hours of 7:30 a.m. and 4:30 p.m., Monday through Friday, CST.
Sincerely,
Mercury Outboard Customer Assistance
In my opinion, I personally think it's wrong to list the compression as brand new, not broken in, or at least make note of average psi after break in is completed, after all it's a service manual to assist in the maintenance of a motor that been run..........:rolleyes::rolleyes:
gotta love mercury, i've seen a couple of mistakes in their manuals
In this manual, they've got an entire page dedicated to revisions to correct mistakes...............LOL.Quote:
Originally Posted by mrcrsr