Flashing the SHO

[GOTTA BIG SACK]

Not sure how its wrong if it still does not exceed the max HP rating for the boat. What's wrong is the amount of money Yamaha charges for a motor that is no different other than a sticker. I would feel good about having mine flashed. Would make me kind of feel like im sticking it to The Man.

[bwp777]

I have a 300 hpdi and if I buy another, it will say 250, 300 or ? depending on what is available when and if I ever need another.
my point is this
buy what you want
mod until you feel better
drive it like you stole it

[21 BULLET]

Ive heard the t2 aren’t anywhere near as good as the t1. I’d put my t1 back on and try it. I know a BUNCH of people that have flashed the SHO on everything from Allison’s to Bullets to Skeeters and not 2 person has ever said it didn’t help. You’re getting 50 more HP at least. It’s got to help. Remember no 2 props are ever the same either

Saw zero change in performance! Sent ECU back to make sure flash took and was confirmed it did. Boat runs same exact speed and RPM's as it did before. Only thing I changed was I went from a 25P T1 to a 25P T2 (just to start with a new fresh prop; nothing wrong with my old prop. I was going to get a bigger P prop but several BBC members said no run the 25P at a higher RPM). Unless there is something horribly wrong with the new prop I am frustrated to say the least and feel I pissed away $700 for nothing. Not sure how guys are seeing the gains because I saw nothing. Boat load same as always and ran it twice in different weather conditions. Hole shot seems worse to me as well. Suggestions? I really don't want to play with buying several props

[Lookout]

Does that void warranty?

[Lookout]

Does it void warranty

[hunter35745]

According to Yamaha techs, yes it voids the warranty if they know it is flashed.

[bgibson]

No it does not, They cant even see the flash.

[Lance B]

Does it help on hole shot or just top end?

[Sinkey]

Yes, it does null your warranty. And YES, techs can tell if its been flashed.

Some techs and dealers just don't care and wont say anything, until you blow your motor. Which has happened to 2 individuals that I know of.

[chrisansilver]

I have a friend that flashed his 250Sho. He did leave the rev limiter stock also.
His relative owns a large Skeeter Dealership here in Texas. The mechanic at the shop ran every test possible on his system and knowing the flash was there could not find anything.

[Loomis88]

I've tried (3) different props and zero change in RPM's, power, or speed. Sent ECU back to make sure flash took and was told it did. I'm beyond frustrated to say the least. I saw zero gain.

[hunter35745]

Loomis88, well that sucks, who did you send it to and what are they giving you for an answer. was thinking about doing mine, but now not so much

[bgibson]

I've tried (3) different props and zero change in RPM's, power, or speed. Sent ECU back to make sure flash took and was told it did. I'm beyond frustrated to say the least. I saw zero gain.

I saw zero gains too! But then I finally got some calm weather to try it out, and really stretched it out. What I found is too around 6000 rpm and 70 mph it gets there fast. Then from there it takes more time to slowly build up speed!! STAY INTO IT ...you will see your speed slowly climb every few seconds!

[bgibson]

Also when you let off the throttle some from WOT you can physically feel the torque on the hull, crazy power. I noticed about 2-3 mph with stock 25 T-1. With extra tip cup and Blueprinted by Croxton I was up 5mph!!

[Y2SAYS]

I'll flash mine when it's out of warranty in 4 years on my 2016 ZX225. Already running over 75mph loaded. Would love to see 80mph+ just for the heck of it.

[Bigcountry35]

Loomis88 I would try to borrow another T1 to compare 0-top end I’ve been working on engines for a long time (Diesel engines) not marine engines but from what I’ve seen which should hold true on any engine ever built as long as your rev limiter is the same the only increase you’ll see is pick up from bottom to top (carrying the same load that the stock engine can carry at 6150 rpms)it should be faster, the top end will most likely stay the same unless you increase pitch. Think of it like this two boats identical hulls set up exactly the same not one thing different on a 20 mile stretch of water one Producing 50 more horsepower running the same prop (switching prop from one to the next) that can reach let’s say 6150 rpms will both run 75 mph one will get there faster but the end result is both reach the same speed now once you increase the load by 500lbs the boat with more power will reach a higher speed because it has the power to still reach max rpms while the other will only turn say 5850 reaching 69 mph. I would think if you spin a 27 inch T1 prop or a reworked prop with more cup and pitch to 6150 you would get the results you’re looking for. Sorry for being long winded, good luck

[Loomis88]

I raised rev limiter to 7k

[reelman]

I would like ONLY guys with a flashed ECU who have run these rigs for 100+ hours to post results ...
(what can happen is too much temptation to mess with the rig after flashing...which can cause blown engines)

No way to verify a post but 25 happy speedy guys in the flash group after 100+ hours would do a lot for the concept.
Also post fuel consumption changes, if any...

(BTW, I had a carb Yam HT kit/w tuner in my 2000 ZX200 back when and it did legit loaded 74.7mph turning a 27 prop 5,700 with awesome hole shot so not in any way negative here)

[kry29]

Have y'all looked at the torque and horsepower curve from the dyno runs? The guys saying they hit the wall are right. There is a bad flat spot around 6k, I think from 5 to 6, but after that it ramps back up. So you have to get past that flat spot to reach the extra gains. Probably the issue Loomis is seeing

[buzzzzbait88]

No it does not, They cant even see the flash.

If hydrotec can hook up and see that the flash took do you really think that Yamaha technicians can't look at the same thing? It seems like it would be pretty obvious for Yamaha to hook up and see exactly what flash is on the ECU.