More Speed!

[Chris W.]

I have a 2022 Yamaha 275SD. It's been years since I owned jetskis. Last one was a 1996 Yamaha Waveraider. I loved it because it was fast and with those triple carborated 2 stroke engines sounded mean. First thing I did was add a few simple mods to get more speed. Has anyone modified their Yamaha jet boats to get more top end speed besides ribbon delete?

 

[HangOutdoors]

You have a very nice boat. You most likely will see minimal gains with most mods plus a chance of something going drastically wrong. There are a couple people who have gotten some serious gains but it was a lot of funds and a lot of work. You can search around the forums here for the thread. I believe it was on a 19' single engine model. Your boat is where it is at and you may be able to get a couple few mph depending on everything you do to it.

 

[Cobra Jet Steering LLC]

I can make it turn a lot faster at plaining speeds and carve a lot sharper in turns but making the top speed higher is going to be a different story but getting it to do the quick turns is a blast and a lot better for towing tubes and other water sport activities.

 

[84rzv500r]

I have a 2022 Yamaha 275SD. It's been years since I owned jetskis. Last one was a 1996 Yamaha Waveraider. I loved it because it was fast and with those triple carborated 2 stroke engines sounded mean. First thing I did was add a few simple mods to get more speed. Has anyone modified their Yamaha jet boats to get more top end speed besides ribbon delete?

Yes I ditched the maintenance intensive and fuel hungry 2 stroke triples and put in bigger stock 4 stroke motors in... if I get 5mph out of adding an honest 50HP in a 2500 lb boat ill be surprised. the boat was already a low to mid 50's boat... your not gonna get much more speed due to the rate that friction (drag) of the water increases with speed...
to go faster with the same power you need to get as much of the boat out of the water as you can to reduce hydrodynamic drag... the other option is to add stupid horsepower

paper on hull design

 

[84rzv500r]

So you want to go faster? how much horsepower do you need?...
so if I run my boat with this formula I get about 3-4 mph increase and maybe 5-6 if I drop the bimini, and get rid of all the weight and 1/3 fuel load...

 

[lazergeek]

So you want to go faster? how much horsepower do you need?...
so if I run my boat with this formula I get about 3-4 mph increase and maybe 5-6 if I drop the Bimini, and get rid of all the weight and 1/3 fuel load...

It would be more then horsepower, as you would need to modify the pumps with higher pitch impellers and also the jet pump output size to accommodate the additional water flow.

 

[84rzv500r]

It would be more then horsepower, as you would need to modify the pumps with higher pitch impellers and also the jet pump output size to accommodate the additional water flow.

not to hijack the thread... yes, I see guys boring out the nozzles... the wall thickness of the cast nozzles is not that thick... in need to review the mechanics of axial flow pumps...

 

[Chris W.]

Well I know on my jet ski you could change out intake grate to force more water in. I just wonder if that had same affect on boats

 

[lazergeek]

Well I know on my jet ski you could change out intake grate to force more water in. I just wonder if that had same affect on boats

Back in the day when I did that with my Sea Doo it only helped with Cavation at higher speeds, didnt really inprove speed it it was flat water. I have not had an issue with high speed cavatation on the boats so dont know that it would help.