Petedacook
Seaman Apprentice
- Joined
- Jul 20, 2015
- Messages
- 44
Hello,
I'm new to boating and the forums. Like the title says, I have a Tohatsu M70A2, 70 HP 2 stroke, that is overheating. I do not know where to start on a boat motor and I need some help, please.
I have used the boat last weekend Sat- Sun and this weekend Sat-Sun. After about 7 hours of boating on the Potomac this past Sunday, I got the overheating warning sound. Water was coming out of the telltale, so I thought this was an error (I know this was a wrong assumption). We traveled about a football field after the sound began, at a light throttle. Engine still starts, idles and seems fine except for a slight back fire every few revolutions. Not sure if backfire is due to a lean mixture with the oil/gas as I went from 40:1 (previous owner recommend) to 50:1 per the manual. Top plug is lean, bottom plug is rich.
I am getting water out of the telltale. After the boat sitting all night, I went to start it this evening and when I turned the switch to on I found the alarm going off. It could not have been hot at this time because it was not running all night/day. I hooked up the muffs and started it. The hot warning sound continued for the 30 seconds or so I had the engine running. How water and exhaust spewed from a hole in the top back of the shaft (I assume this is normal?). I don't know if this is a blown head gasket or what.
I have checked the manual and the only thing I can find in there is where the impeller is located. What are my trouble shooting steps with this engine? I have worked on cars for years, but I am at a loss when it comes to where to start on troubleshooting an outboard.
Can anyone please give some advice? Tohatsu guru, can you give me the advice I need?
Thanks for any help,
Pete
I'm new to boating and the forums. Like the title says, I have a Tohatsu M70A2, 70 HP 2 stroke, that is overheating. I do not know where to start on a boat motor and I need some help, please.
I have used the boat last weekend Sat- Sun and this weekend Sat-Sun. After about 7 hours of boating on the Potomac this past Sunday, I got the overheating warning sound. Water was coming out of the telltale, so I thought this was an error (I know this was a wrong assumption). We traveled about a football field after the sound began, at a light throttle. Engine still starts, idles and seems fine except for a slight back fire every few revolutions. Not sure if backfire is due to a lean mixture with the oil/gas as I went from 40:1 (previous owner recommend) to 50:1 per the manual. Top plug is lean, bottom plug is rich.
I am getting water out of the telltale. After the boat sitting all night, I went to start it this evening and when I turned the switch to on I found the alarm going off. It could not have been hot at this time because it was not running all night/day. I hooked up the muffs and started it. The hot warning sound continued for the 30 seconds or so I had the engine running. How water and exhaust spewed from a hole in the top back of the shaft (I assume this is normal?). I don't know if this is a blown head gasket or what.
I have checked the manual and the only thing I can find in there is where the impeller is located. What are my trouble shooting steps with this engine? I have worked on cars for years, but I am at a loss when it comes to where to start on troubleshooting an outboard.
Can anyone please give some advice? Tohatsu guru, can you give me the advice I need?
Thanks for any help,
Pete