Compression test low on BF100 honda mid 80s

[infoanalysis]

I think you got a direct answer / opinion about needing the throttle OPEN.------Then you doubted that information with your reply in post #4 I think.

your right

 

[infoanalysis]

Yep, will second Ahicks post. Motors can carbon up due to : Not using a thermostat will make the motor to run much cooler that it should, will lessen top cylinder combustion, incorrect spark plug thermal range and gap will also contribute to increase this carbon up escenario. On 2 stroke motors the combination of both it's a serial killer.

Happy Boating​

 

[infoanalysis]

I spoke to a honda OB mechanic he said you would never get it started at only 60 psi. Yet it starts up ok-- not great, but does send alot of spent oil into the water tank as if it were a 2 stroke. I also have an issue with the impellor which I think I solved because of the lower ring seal not present on the water tube and imp housing-- could that explain the excessive oil? Or is it because of blow by from the low compression?

 

[MattFL]

If you have low compression AND you're burning oil, then that's a big red flag that your piston/rings/cylinder are likely worn or in the least the rings are stuck. But you did say that you were putting oil into the cylinders, are you sure it's not just that oil coming out? Did you ever verify whether that motor has an automatic compression release? If it does, you need to account for that when doing a compression test.

 

[racerone]

I doubt there is compression release on these Honda outboards.

 

[Faztbullet]

Still I have never seen a 4 stroke outboard carbon the rings unless it uses oil. Maybe a saltydog thing

 

[ahicks]

Still I have never seen a 4 stroke outboard carbon the rings unless it uses oil. Maybe a saltydog thing

Nope. It's a pontoon boat thing.....