Thread: Riva Stage II with Waterbox Mod
02-21-2006, 10:10 AM #1
- Join Date
- Apr 2005
Riva Stage II with Waterbox Mod
There have been some posts stating that running this setup causes a lean condition.
Has anyone verified this or is running this setup without having any problems. A solution was to go with with a RR ECU or a piggy back fuel controller but I don't want to spend more money on the ski. The Riva Stage2 is already on my ski, now I don't know what to do with my modded wterbox. Is there a way to know if I am running lean?
02-21-2006, 10:12 AM #2
John, the only way to know for sure is to install an air/fuel ratio gauge
Im sure you are fine though. There are many Riva Stage 2 kits out there running strong with no issues. Riva dyno tests their kits to ensure they are safe.
02-21-2006, 10:22 AM #3
- Join Date
- Apr 2005
Thanks Green. I actually didn't care about it until I read the post by 2corrupt regarding the waterbox mod and Riva Stage2. now I don't know what to think!
By the way, I strapped the heat sensor on the waterbox onto the coolant hose. What does that heat sensor exactly do? Does it relay info regarding how hot the echaust gases are to the ECU?
02-21-2006, 10:41 AM #4
John, the reason we strap the heat sensor to the coolant line is because when you run an modded waterbox it may sense "hot" telling the ECU to richen things up to cool things off. This robs power.
02-21-2006, 11:09 AM #5
I decided to try something different with the waterbox so that I could keep the sensor where it is. I cut the waterbox in two BEHIND the second (input) pipe, still trimmed the 2.5 inches off the bottom of the J pipe where it goes into the waterbox, and then cut out most of the baffling, but left the exit pipe intact, going down close to the bottom of the front of the water box. I was amazed at how constricted the stock baffling setup was, routing all the exhaust under a very small opening before it could get to the exit pipe.
I was thinking that by leaving the exit pipe stock, it would still suck water out like usual, but that the waterbox would pressurize equally very quickly and the back pressure would be greatly reduced. Thing is, I now wonder if it will be quite loud ... I guess I will find out and will weld in additional baffles if I need to. I don't think it will even be as loud as the classic RR waterbox mod most of you have done, but I won't know for a couple months.
The way the waterbox works is basically high and low pressure ... the exhaust from the motor creates high pressure in the waterbox and the exit pipe is then the low pressure point, effectively creating a vacuum that 'sucks' the water and exhaust out. The water not only cools things, it muffles, which is likely why the RR waterbox mod is not as loud as it looks like it might be. I am hoping my mod will not be much louder either, since the exit is still deep in the waterbox and therefore should have water coming thru it all the time too.
02-21-2006, 11:17 AM #6
Vern please post when you find out how loud it is.
I want to do a waterbox mod but I'm afraid it will be too loud.
02-21-2006, 08:18 PM #7(input) pipe, still trimmed the 2.5 inches off the bottom of the J pipe where it goes into the waterbox
I thought it was 1 3/4 " according to jerry's pics on his blog should I go 2.5"? anyone know. I just finished my waterbox mod, and got it welded up today. I'm installing it in a few minutes, and I'll let ya know how loud it makes it compared to stock(still with PPG power pipe) also I'll see if any leaner at idle, Until I get it to the water.
02-21-2006, 08:48 PM #8
- Join Date
- Jul 2005
[/quote]John, the reason we strap the heat sensor to the coolant line is because when you run an modded waterbox it may sense "hot" telling the ECU to richen things up to cool things off. This robs power.
Jerry, if the setup or some of the setups are running lean would it also be a good idea to put the sensor back in place to allow the ECU to factor in some more fuel, maybe even place it in a hotter location? although I can't think of a hotter place than the muffler? LOL
02-21-2006, 08:50 PM #9
Tim, then you would suffer poor performance from running too rich.
Strapped to the coolant line is where you want it if you have a modded waterbox.
02-21-2006, 10:33 PM #10
Well the waterbox mod with PPG power pipe sounds almost like a thru hull exhaust. Just a little bit louder, and more throaty My A/F was at 10.7 idle before, and is now at 11.4 ish at idle. I'll have to check it fully warmed up , and in the water (maybe tomorrow). Still fine,and more
on the rich side
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By cincygpr in forum Yamaha ClassifiedsReplies: 15Last Post: 12-11-2009, 09:55 PM
By gmoeller in forum Yamaha PWC Performance (4-stroke)Replies: 92Last Post: 08-18-2009, 08:20 PM
By bankyf in forum 4-Tec PerformanceReplies: 46Last Post: 07-25-2007, 11:06 AM
By Sirhc7897 in forum 4-Tec PerformanceReplies: 13Last Post: 02-01-2006, 12:18 PM
By Hecyan in forum 4-Tec PerformanceReplies: 4Last Post: 07-14-2005, 09:38 PM