Great video!! Have a 9.8 that starts extremely hard. New cdi box and carb rebuild,still doesn't run right. Will tear into it soon I'm sure it could use the same attention that you gave your motor. Thanks for opening this up have been looking for this info for months?
Hi i have the exact same motor, and you mentioned the old service manual, do you have a physical copy or softcopy because it would be really helpful to have one. Maybe you could send an online copy of it to me. Thanks
Great video Al, very informative and my guide for rebuilding my 1975 Mercury 7.5. Just ordered and waiting for my parts to start reassembly. Did you use stainless lock washers with your Allen bolts or just flat stainless washers? I also bought all new stainless hardware (Allen bolts, nuts - regular & nylon locking, washers - flat & split) but unsure about using nylon lock nuts with the heat of the motor. What do you recommend for securing the bolts...nylon lock nut, split washer, or just a flat washer with loctite on threads? Thanks!
@@ajsnowskis Are you also putting Permatex High Tack Gasket Sealant on the Transfer Port Cover gasket and Exhaust Manifold gasket? Or only on the Cylinder Block cover gasket like you did in the video...thanks!
I have the exact motor in the 1979 vintage. It runs great when warm but is hard starting and has a rough idle - almost like it's skipping or backfiring when idling. I have replaced plugs and regasketed the fuel intake screen on the carb where it was leaking (little blue cover on the carb). Checked the fuel system/bulb and tank as well for leaks. Where should I go next? Compression check? (What is the spec?). Swap out the brass check valve? I don't know if I am capable of a complete rebuild with my tools and knowledge.
Was looking for advice for other issue on same engine but on other site got answer what the thin hose is on the side of engine block. This hose empties collected oil/gas by bottom bearing and if not done the fuel will be crazy rich and making starting difficult. Perhaps it helps. Great engine and worth saving!
Are you also putting Permatex High Tack Gasket Sealant on the Transfer Port Cover gasket and Exhaust Manifold gaskets? Or only on the Cylinder Block cover gasket like you did in the video...thanks Al!
No solvent based gasket sealant should be used anywhere at all on that engine. The intake and exhaust port covers simply require clean, flat surfaces and a new gasket. Don't copy this guy and put that sealant junk on this engine. It will never last and will only cause problems in the future.
Great video, I have the identical motor. Mine is missing the hose that connects to the check valve you tested. Where does the other end of that hose go? I’m looking to replace . Thanks
I got my valves carbon fiber ones, what process did you use to put the Pistons back in place? Thanks I tried sending you some pictures but I need your email thanks again
Awsome!!! How do I get a parts list for this engine? I have exactly this Mercury model not reliable on starts for years. I presume you gave me the answers for such problems. I am in Brazil and to get that parts are abreal challenge! Congratulations!
I'm trying to get my 7.5 going and I'm having quite the hard time finding its year and I need a new stator or ignition coil much less a service manual I certainly will appreciate any advice or tips you can give and point me in the right direction thanx.
Both seals are 1.125" OD, 0.75" ID and 0.25" thick. When you remove the old seals note which way the inside rubber lip is facing! Write it down. Merc part no 26-66301. Look on Marineengine.com or a power transmission supplier or search Amazon or google on the part no
I don't know why you wouldn't put the spark plugs in when pressure testing and let stand at 7 LBS....otherwise you are GUESSING there is no leaks. Also if you own a Mercury, go to a parts store and get a few rolls of wire and then order a new CDI box ....the wiring in EVERYTHING will turn to DUST.
I don't care about piston blow by. My concern is the integrity of the top and bottom crank shaft seals. The crank case MUST be totally sealed if the engine is to run correctly.
Thanks Al, unfortunately I don't do social media so i'll see if I can find an answer elsewhere. I see you have a washer, I was just curious if it was a flat or lock washer...thanks!
WOW! I have NEW HOPE now for my beloved 1973 9.8 hp! Thank you for this excellent video!
I've bought the same outborder for cheap and am about to inspect it as well. this was really informative thank you
Thanks for part 2! Great info!
Incredible work and explanation!
Trying to rebuild my merc now. Not running hopi g this video helps me
Thanks for sharing great video.
Fantastic videos, I have a 7.5 and I’m going through the carb now. I’m not sure of the year but it looks identical to yours.
www.maxrules.com/merc_contents.php
Great job, I'm rebuilding one.I would like to know where did u get the new rings. Thanks
Great video!! Have a 9.8 that starts extremely hard. New cdi box and carb rebuild,still doesn't run right.
Will tear into it soon I'm sure it could use the same attention that you gave your motor.
Thanks for opening this up have been looking for this info for months?
Where did you find the reed valves and seal and gasket set? I have one to rebuild myself. You did a great job
Hi i have the exact same motor, and you mentioned the old service manual, do you have a physical copy or softcopy because it would be really helpful to have one. Maybe you could send an online copy of it to me. Thanks
Great video Al, very informative and my guide for rebuilding my 1975 Mercury 7.5. Just ordered and waiting for my parts to start reassembly. Did you use stainless lock washers with your Allen bolts or just flat stainless washers? I also bought all new stainless hardware (Allen bolts, nuts - regular & nylon locking, washers - flat & split) but unsure about using nylon lock nuts with the heat of the motor. What do you recommend for securing the bolts...nylon lock nut, split washer, or just a flat washer with loctite on threads? Thanks!
Locktite and a flat washer with correct torque
@@ajsnowskis Are you also putting Permatex High Tack Gasket Sealant on the Transfer Port Cover gasket and Exhaust Manifold gasket? Or only on the Cylinder Block cover gasket like you did in the video...thanks!
I have the exact motor in the 1979 vintage. It runs great when warm but is hard starting and has a rough idle - almost like it's skipping or backfiring when idling. I have replaced plugs and regasketed the fuel intake screen on the carb where it was leaking (little blue cover on the carb). Checked the fuel system/bulb and tank as well for leaks. Where should I go next? Compression check? (What is the spec?). Swap out the brass check valve? I don't know if I am capable of a complete rebuild with my tools and knowledge.
Was looking for advice for other issue on same engine but on other site got answer what the thin hose is on the side of engine block. This hose empties collected oil/gas by bottom bearing and if not done the fuel will be crazy rich and making starting difficult. Perhaps it helps. Great engine and worth saving!
Are you also putting Permatex High Tack Gasket Sealant on the Transfer Port Cover gasket and Exhaust Manifold gaskets? Or only on the Cylinder Block cover gasket like you did in the video...thanks Al!
No solvent based gasket sealant should be used anywhere at all on that engine. The intake and exhaust port covers simply require clean, flat surfaces and a new gasket. Don't copy this guy and put that sealant junk on this engine. It will never last and will only cause problems in the future.
Great video, I have the identical motor. Mine is missing the hose that connects to the check valve you tested. Where does the other end of that hose go? I’m looking to replace . Thanks
Intake port cover
ajsnowskis Great! Thanks, it was hiding behind the starter.
What is the torque spec for the flywheel on this engine? I have the 9.8 version (1979)
I got my valves carbon fiber ones, what process did you use to put the Pistons back in place? Thanks I tried sending you some pictures but I need your email thanks again
Join Vintage mercury outboard enthusiasts on facebook and ask and post there
What did you use to clean the pistons?
Awsome!!! How do I get a parts list for this engine? I have exactly this Mercury model not reliable on starts for years. I presume you gave me the answers for such problems. I am in Brazil and to get that parts are abreal challenge! Congratulations!
Marineengine.Com has all the parts diagrams and many parts
What size ball hone did you use?
I'm trying to get my 7.5 going and I'm having quite the hard time finding its year and I need a new stator or ignition coil much less a service manual I certainly will appreciate any advice or tips you can give and point me in the right direction thanx.
www.maxrules.com/merc_contents.php
by chance do you have the crankshaft end seals part numbers and company so i could purchase them...
Both seals are 1.125" OD, 0.75" ID and 0.25" thick. When you remove the old seals note which way the inside rubber lip is facing! Write it down. Merc part no 26-66301. Look on Marineengine.com or a power transmission supplier or search Amazon or google on the part no
where can i by part`s for this engine? can't find any?
Marineengine.Com and Google is your friend
@@ajsnowskis :-)
TAKK
where did you get the rings and gaskets?
Oldmercs.com
I don't know why you wouldn't put the spark plugs in when pressure testing and let stand at 7 LBS....otherwise you are GUESSING there is no leaks. Also if you own a Mercury, go to a parts store and get a few rolls of wire and then order a new CDI box ....the wiring in EVERYTHING will turn to DUST.
I don't care about piston blow by. My concern is the integrity of the top and bottom crank shaft seals. The crank case MUST be totally sealed if the engine is to run correctly.
I something u like
Join Vintage Mercury Outboard Fanatics on facebook and ask there
Thanks Al, unfortunately I don't do social media so i'll see if I can find an answer elsewhere. I see you have a washer, I was just curious if it was a flat or lock washer...thanks!