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Took a nice late afternoon ride today out along the Erie Canal again. Word is that they're filling it back up again, but it looks like that hasn't happened in my area yet. Gates are still open, but the waterflow is definitely more volume.

Anyway, while driving along the roads that run to the north and south of the canal, and that parallel the NY Thruway, (routes 5 and 5s), I found myself on several stretches of road that offered miles long straights with not another car in sight. So I pinned the throttle and let the bike accelerate to as fast as it could go. Aside from my change to the 130 main jet, and having my air screw set to 2 turns out, nothing else is different from stock. I got to 65 MPH every time I was on level ground, maybe 66 if I leaned forward and squinted my eyes. I could almost track those ever-so-slight upgrades by how the bike would lose that top speed by a coupla-few MPH. Tires were both inflated to about 25psig which is a bit higher than I usually run.

I may put the stock main jet back and do this again just to see if there's a difference. I know I've had the bike up to almost 70 before, but a gentle down-slope may have contributed to that.
 
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I don't know what year yours is but my 2018 will run 70mph with me and the wife. We hit 70 last weekend on a little stretch of 4 lane. And it had some left. Completely stock with saddle bags and a jimbo. Both of us together weigh about 300lbs with gear. Temperature was 95 degrees and no wind. Small hills.

Maybe you need a newer style carb if you have an older model?
 

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Discussion Starter #3
Mine is a 2009. When I said I had it up to almost 70, it was with my girlfriend on with me, probably about 340lbs total, and it still had the stock jet in that time. I may go back to stock and see if I notice a difference. I do notice easier starting and little to no warm-up with the 130 installed, so it's a tradeoff I guess.
 

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Based on my experience with the older style carburetor and I have said it many times before, get a brand new stock jet. Don't use the one you removed. That little hole in the center corrodes and erodes and becomes bigger and makes the mixture richer, richer than the next sized larger jet makes it richer. Installing a new next size larger jet actually leans the mixture. The bike runs better with the next sized larger jet and everyone concludes it needed to be richer.

No one believes that the jets wear out. The hole looks the same but it isn't.
 

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No one believes that the jets wear out. The hole looks the same but it isn't.
I must advise the same. My basecamp is at 9,000ft - as such, I normally run a 110 main jet. I should point out that I would love to try a factory 112 main jet, but they are about 4x the price as other sizes? Anyway, I switch back to the factory 114 main jet when I ride the down in "mile-high" elevations. As soon as I began experimenting with main jet sizes, I immediately realized the 114 that was installed in the bike was noticeably "duller" in appearance. I just received a new Yamaha 114 jet, and look forward to re-testing the bike at "low?" elevation. Jets are generally cheap - even factory Yamaha ones. Buy a new one and compare it to the old one. Then throw it in and see what happens...
 

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I must advise the same. My basecamp is at 9,000ft - as such, I normally run a 110 main jet. I should point out that I would love to try a factory 112 main jet, but they are about 4x the price as other sizes? Anyway, I switch back to the factory 114 main jet when I ride the down in "mile-high" elevations. As soon as I began experimenting with main jet sizes, I immediately realized the 114 that was installed in the bike was noticeably "duller" in appearance. I just received a new Yamaha 114 jet, and look forward to re-testing the bike at "low?" elevation. Jets are generally cheap - even factory Yamaha ones. Buy a new one and compare it to the old one. Then throw it in and see what happens...
I have a 1989 TW and wanting to ride anywhere from 8000 to 11,000 ft, what main jet do you recommend?
 

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If that is the original jet in your '89 it is overdue for a new one.

I am at sea level and use a #112 main jet and it works very well. I have tried the #110 jet at sea level and found it to be a little to lean but it might be perfect at 5000 feet and usable to 11,000 feet. For 8000 to 11,000 feet I would experiment with a #108 and #105 just to see how it runs.

I have used a new #114 at 5000 feet and it was very adequate but I bet at 11,000 feet your engine will be sluggish.

Which jet to use? How long will you be at that altitude?
 

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If that is the original jet in your '89 it is overdue for a new one.

I am at sea level and use a #112 main jet and it works very well. I have tried the #110 jet at sea level and found it to be a little to lean but it might be perfect at 5000 feet and usable to 11,000 feet. For 8000 to 11,000 feet I would experiment with a #108 and #105 just to see how it runs.

I have used a new #114 at 5000 feet and it was very adequate but I bet at 11,000 feet your engine will be sluggish.

Which jet to use? How long will you be at that altitude?
I m sure it’s a stick jet. Going to dealer next week to pic up a couple to try. We should be up in higher elevations about 10 days.tha is for the info
 
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