kanguru007
New member
The answers to all these questions are in the service manual. The service manual us publicly available. Thank you Yamaha for being so good to us. I will never buy an outboard from a different brand.
Detune / Retune of Yamaha 6 / 8hp Outboard
- Thread starter OGITD
- Start date
The answers to all these questions are in the service manual. The service manual us publicly available. Thank you Yamaha for being so good to us. I will never buy an outboard from a different brand.
kanguru007
New member
Resa
New member
Hi folks, I just tuned -95 yamaha 6hp 2-stroke by drilling the choking parts away from exhaust side, the goal is to make it 8hp model
. In the same time I decided to overhaul water pump even though water flew from telltale just fine. I changed impeller, pump housing+insert and gasket of course.
Now I'm facing strange problem. Water is coming normally from upper hole of the water pump when rotating gearbox (with cordless drill) in water tank. But when the gearbox is assembled to engine, I cannot get any water from telltale when running the motor, only exhaust gas is coming out from hole.
I thought the reason could be increased exhaust pressure...maybe, I really do not understand this.
I'm sure many has done this very same tune, probably someone has encountered the same problem?
. In the same time I decided to overhaul water pump even though water flew from telltale just fine. I changed impeller, pump housing+insert and gasket of course. Now I'm facing strange problem. Water is coming normally from upper hole of the water pump when rotating gearbox (with cordless drill) in water tank. But when the gearbox is assembled to engine, I cannot get any water from telltale when running the motor, only exhaust gas is coming out from hole.
I thought the reason could be increased exhaust pressure...maybe, I really do not understand this.
I'm sure many has done this very same tune, probably someone has encountered the same problem?
Steve65
Active member
Exhaust plate is bigger on the 8hp and bigger carb
Rappey
Well-known member
Have you drilled through something you should not have and altered where the flow goes ? Maybe the waterpipe that goes from the impellor to powerhead is not correctly located in the power head?