To Gregwill clark
Question: Will increasing jet sizes work?
Answer: Possibly.
Question that you didn't ask: Am I likely to get it right?
Answer: Unlikely.
Question that you didn't ask: Why am I unlikely to get it right?
Answer: You don't have Yamaha's engine test facilities at your disposal.
Summary:
If I were you I'd try sleeving the exhaust outlet down first.
Because piss-malling about with jet sizes, often results in a significant amount of wasted time and effort.
Attached is a photo of a the first piece of pipe I used to sleeve down the outlet.
Question: Will increasing jet sizes work?
Answer: Possibly.
Question that you didn't ask: Am I likely to get it right?
Answer: Unlikely.
Question that you didn't ask: Why am I unlikely to get it right?
Answer: You don't have Yamaha's engine test facilities at your disposal.
Summary:
If I were you I'd try sleeving the exhaust outlet down first.
Because piss-malling about with jet sizes, often results in a significant amount of wasted time and effort.
Attached is a photo of a the first piece of pipe I used to sleeve down the outlet.