- Location
- Plymouth, MA
Did Yamaha make any boats with 760 motors with dual 38's? or are all 760 models with 44's.
Any feed back appreciated.
Thanks WB
Any feed back appreciated.
Thanks WB
Other 760 Yamaha with dual 38's
- Thread starter WB800BLASTER
- Start date
WFO Speedracer
A lifetime ban is like a lifetime warranty !
- Location
- Alabama
All 760's had dual 44's , 62T 701's came with dual 38's
- Location
- Lake Lanier
A friend of mine is running 38s on a 760 right now and they work well. He’s saying they have better bottom end snap.
bored&stroked
Urban redneck
- Location
- AZ
All 44's.
Doesn't mean you can run 38's on them, lots have/do. I plan on doing that when I bore my 701 out to 760 in my blaster for fuel mileage.
Doesn't mean you can run 38's on them, lots have/do. I plan on doing that when I bore my 701 out to 760 in my blaster for fuel mileage.
WFO Speedracer
A lifetime ban is like a lifetime warranty !
- Location
- Alabama
I have heard of several people doing this over the years , what they have said is that it has better bottom end , it sacrifices a bit on top but is way better on fuel consumption .
- Location
- 1 Mile High in Colorado
I would disagree on the better bottom end. It's equal if not every so slightly worse IMO. Top end becomes very 'safe' feeling - but definitely loses the mid to WOT pull for sure. I was able to pull 47mph with 38s and keep it pinned WOT for 10+ seconds.
I made the jump down primarily to get nearly 100% better fuel mileage lol. I seriously was only getting around 25 miles per tank. Going to 38s got me back to 40+.
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WFO Speedracer
A lifetime ban is like a lifetime warranty !
- Location
- Alabama
Yep they are defiantly thirsty.
bored&stroked
Urban redneck
- Location
- AZ
How did you get an odometer on a ski?
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
- Location
- 1 Mile High in Colorado
Usually someone tracks miles on a phone in a dry pouch. We do a lot of river / tributary and lake fork exploring so we can cove chase - so we've done some 90 mile days (2+ refills). I think we've seen just about every piece of coast line at lake havasu from the dam to the sandbar as well as all of river dam to dam in parker.How did you get an odometer on a ski?
waxhead
wannabe backflipper
- Location
- gold coast
He probably has not come out with a tune on his 44s that works as well as they should
waxhead
wannabe backflipper
- Location
- gold coast
The question I have for those who think 38s are better is this: why are flat water freestyle riders trying to fit the largest possible carb on their backflip skis? If anyone needs low-end snap, it’s the rider attempting a double backflip on flat water, right?
holygoat
Site Supporter
- Location
- Indiana, USA
I would assume the caveat of "are the best on an engine under 750cc if specifically looking for low end and throttle response.
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A pair of 38s can run much cleaner part throttle mixture than 44s and still have good response. That is the main reason for better fuel economy. I have always found 44s and larger carbs must be fourcycling more below the pipe for best response and they do make the pipe hit harder. This tends to burn a lot more gas when you are going slow. Top rpm is nearly the same. That was my experience swapping OEM 38s for OEM 44s on a 701.
waxhead
wannabe backflipper
- Location
- gold coast
If you're looking for fuel economy, then smaller carbs will definitely deliver that. But if you're after acceleration, the bigger carbs are going to give you more. Personally, I don’t focus on economy in my skis—I’m all about power. I’ll concede that 38s will give you better fuel efficiency, but I prefer power over economy any day of the week. After all, we love the brapp, don’t we?
You’re also right—bigger carbs don’t significantly improve top-end speed, or only very little.
You’re also right—bigger carbs don’t significantly improve top-end speed, or only very little.
- Location
- Lake Havasu City, AZ USA
Ya, but what about OEM 44's vs. aftermarket Mikuni 44's? That's where the real difference is... Am I wrong?
- Location
- Plymouth, MA
Thank you all for the feedback.
To clarify why I asked….I have plenty of jetting settings for OEM 760 boats with 44’s. I wanted to see what the OEM spec change was on a 760 with 38’s if they existed.
To clarify why I asked….I have plenty of jetting settings for OEM 760 boats with 44’s. I wanted to see what the OEM spec change was on a 760 with 38’s if they existed.
Agree.
No stock 760 came with dual 38s, but dual 38 will work well on 760s in custom setups.
I have a 701 62t cylinder that is bored to 84mm, so the same bore as a stock 760, so the only difference is a little lower exhaust port timing, pretty standard setup ada head with pretty conservative compression (40cc domes), b-pipe, zeel, aftermarket flame arrestors, home job porting with the yamanube template.
I haven't touched it in years but my notes say I'm running 75 low and 125 high with 1.5 seat and 80 gram spring.
I would recommend starting a bit richer than that and working your way down, but it does seem like dual 38's rarely need to be very far from 70/130.
For what it's worth I also have a 760 based 781 with more compression and more porting and it ran 44mm oem carbs for a while, that motor liked jetting that was nowhere near what a stock 760 runs. It makes a hell of a lot more power than my 760 with 38's, but it should for a few reasons not just the carbs.
I am not a jetting master and you should take any jetting specs from the internet as a starting point at best imo.
I haven't touched it in years but my notes say I'm running 75 low and 125 high with 1.5 seat and 80 gram spring.
I would recommend starting a bit richer than that and working your way down, but it does seem like dual 38's rarely need to be very far from 70/130.
For what it's worth I also have a 760 based 781 with more compression and more porting and it ran 44mm oem carbs for a while, that motor liked jetting that was nowhere near what a stock 760 runs. It makes a hell of a lot more power than my 760 with 38's, but it should for a few reasons not just the carbs.
I am not a jetting master and you should take any jetting specs from the internet as a starting point at best imo.