Hi everyone,
Long time lurker here but after continued problens with my 2 stroke Yamaha 70TLR, I feel compelled to make this post hoping someone will be able to help me with this problem. Here is the rundown:
My Yamaha 70TLR loves to violently shake at rpms lower than 1700, so bad that it makes all the screws in my hull come loose, even with 5200. It runs amazing at higher rpms and at WOT and doesn't have any problems getting up onto plane. It is extremely uncomfortable trolling and going idle speed however, and I try and avoid bringing passengers since my motor is a tooth breaker. Here is a list of everything I have done to it to try and solve the issue:
Fuel
- Replaced all fuel lines and connections going from the tank to the motor
- Replaced fuel pump
- Replaced fuel water seperator
- Stripped and rebuilt carbs with ultrasonic cleaner
- Have replaced fuel/air mixture screws
- Flushed gas and ran ethanol free fuel
- Ran seafoam
Electrical
- New spark plugs (gapped)
- New spark plug boots and coils
- Timing adjustments with gun
- Cleaned grounds
- New batteries
- Multi-meter tests on everything stated in the workshop manual
Other
- New propeller
- New lower unit
- Good compression
As you can see, I have pretty much replaced and tested everything on this motor that I can think of and it still runs like garbage below 1700 rpms. I am almost at my wits end trying to solve this and am about to scrap the motor. I know 2 stroke 3 cylinders rough, but I have been on boats with the same motor and they definitely don't shake bolts loose. Any suggestions are welcomed and I appreciate any and all advice you guys have to offer. Thanks so much and I look forward to potentially solving the issue!
Long time lurker here but after continued problens with my 2 stroke Yamaha 70TLR, I feel compelled to make this post hoping someone will be able to help me with this problem. Here is the rundown:
My Yamaha 70TLR loves to violently shake at rpms lower than 1700, so bad that it makes all the screws in my hull come loose, even with 5200. It runs amazing at higher rpms and at WOT and doesn't have any problems getting up onto plane. It is extremely uncomfortable trolling and going idle speed however, and I try and avoid bringing passengers since my motor is a tooth breaker. Here is a list of everything I have done to it to try and solve the issue:
Fuel
- Replaced all fuel lines and connections going from the tank to the motor
- Replaced fuel pump
- Replaced fuel water seperator
- Stripped and rebuilt carbs with ultrasonic cleaner
- Have replaced fuel/air mixture screws
- Flushed gas and ran ethanol free fuel
- Ran seafoam
Electrical
- New spark plugs (gapped)
- New spark plug boots and coils
- Timing adjustments with gun
- Cleaned grounds
- New batteries
- Multi-meter tests on everything stated in the workshop manual
Other
- New propeller
- New lower unit
- Good compression
As you can see, I have pretty much replaced and tested everything on this motor that I can think of and it still runs like garbage below 1700 rpms. I am almost at my wits end trying to solve this and am about to scrap the motor. I know 2 stroke 3 cylinders rough, but I have been on boats with the same motor and they definitely don't shake bolts loose. Any suggestions are welcomed and I appreciate any and all advice you guys have to offer. Thanks so much and I look forward to potentially solving the issue!
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