CARB vs. Non-CARB Side by Side Test

[Mainah]

So when I learned that my boat was a CARB model I was not happy and called my dealer. My dealer offered to let me drive a non-carb 2016 ar240 they had then drive my CARB 2016 242 LS back to back to see if there was any real difference. The dealer boat was at 51% fuel and mine at 46%. Me and the dealer as the only passengers. With various things on my boat and mods I have done on top of it already being a few pounds heavier stock lets say my boat weighed about 50 lbs more. Throttle adjustments were checked on both boats before taking off and both boats hulls were clean. The test was done at 83 degrees and 267' elevation with 5 mph winds and a moderate chop from boat traffic.

The results were that the non-CARB boat hit 50 mph momentarily but could hold 49 mph. My CARB boat hit hit 49 momentarily and held 48 mph. I did not use a stop watch but it seemed that it took my boat a bit longer to get to top speed at WOT. After this test I dropped in on @Kane to check out his black non-carb 2016 242x (sweet boat). An hour later he took me and friend out and then asked if I wanted to take the helm ... heck yeah. So with 3 people and little under half a tank on the same lake with less chop his boat topped out and maintained 49mph. So after testing 3 different boats on the same day at the same lake I can say there is a difference of about 1-2 mph with a light load.

My other observations were that the non-carb boats bleed off a bit less speed in a hard turn and exit the turn a bit faster. I think they also got to top speed faster. Later that same day I was back at my home lake which is at 164' elevation now with a full tank of gas, a bit windy with light chop, 79 degrees, and 3 people on board and it hit and maintained 47mph. I think the biggest difference comes when under load which makes sense. I will not be repeating the test but I wonder how things would stack up with full tanks and 10 people on board?

Is there a difference? Yes. Is it a big difference? With light load no. With heavy load I can't say for sure but I think it could be just a bit more. For those seeing quite a bit lower top speeds I do suggest checking your throttle adjustments and making sure your hull is clean. Then adjust for any high elevations.

I learned that dealers are receiving more CARB models from Yamaha each year. Also there are other boat manufactures that are 100% CARB. My dealer is not a large one and I am the first person who had come to them on the CARB thing after receiving my boat. They did not even consider that when ordering my boat and ordered the only one available at the time in the color option I wanted. James at Long Lake Marina went the extra mile for me and offered this above side by side comparison to put my mind at ease.

Am I happy that I may have to replace cats or o2 sensors down the road? Of course not. Am I happy that dollar for dollar there are boats out there exactly like mine except for being non-carb that will perform just a bit better? Heck no. Am I going to enjoy the boat and dwell on this less? Yes.

 

[robert843]

Great report! I have a non carb model and to hit 50mph in it is a struggle while under load the only times I get there easily is if there are 3 or less people on board. Under a normal load 5-8 people and full tank of gas it usually tops out at about 47-48. Under heavy load sometimes I can hit 50 but I have to run at WOT for a pretty good amount of time to get there like 3-4 minutes or more.

 

[swatski]

So when I learned that my boat was a CARB model I was not happy and called my dealer. My dealer offered to let me drive a non-carb 2016 ar240 they had then drive my CARB 2016 242 LS back to back to see if there was any real difference. The dealer boat was at 51% fuel and mine at 46%. Me and the dealer as the only passengers. With various things on my boat and mods I have done on top of it already being a few pounds heavier stock lets say my boat weighed about 50 lbs more. Throttle adjustments were checked on both boats before taking off and both boats hulls were clean. The test was done at 83 degrees and 267' elevation with 5 mph winds and a moderate chop from boat traffic.

The results were that the non-CARB boat hit 50 mph momentarily but could hold 49 mph. My CARB boat hit hit 49 momentarily and held 48 mph. I did not use a stop watch but it seemed that it took my boat a bit longer to get to top speed at WOT. After this test I dropped in on @Kane to check out his black non-carb 2016 242x (sweet boat). An hour later he took me and friend out and then asked if I wanted to take the helm ... heck yeah. So with 3 people and little under half a tank on the same lake with less chop his boat topped out and maintained 49mph. So after testing 3 different boats on the same day at the same lake I can say there is a difference of about 1-2 mph with a light load.

My other observations were that the non-carb boats bleed off a bit less speed in a hard turn and exit the turn a bit faster. I think they also got to top speed faster. Later that same day I was back at my home lake which is at 164' elevation now with a full tank of gas, a bit windy with light chop, 79 degrees, and 3 people on board and it hit and maintained 47mph. I think the biggest difference comes when under load which makes sense. I will not be repeating the test but I wonder how things would stack up with full tanks and 10 people on board?

Is there a difference? Yes. Is it a big difference? With light load no. With heavy load I can't say for sure but I think it could be just a bit more. For those seeing quite a bit lower top speeds I do suggest checking your throttle adjustments and making sure your hull is clean. Then adjust for any high elevations.

I learned that dealers are receiving more CARB models from Yamaha each year. Also there are other boat manufactures that are 100% CARB. My dealer is not a large one and I am the first person who had come to them on the CARB thing after receiving my boat. They did not even consider that when ordering my boat and ordered the only one available at the time in the color option I wanted. James at Long Lake Marina went the extra mile for me and offered this above side by side comparison to put my mind at ease.

Am I happy that I may have to replace cats or o2 sensors down the road? Of course not. Am I happy that dollar for dollar there are boats out there exactly like mine except for being non-carb that will perform just a bit better? Heck no. Am I going to enjoy the boat and dwell on this less? Yes.

Great report, thank you for sharing!
Was there any difference in RPM or not noticeable?
Do you and/or dealer have an opinion on removing the ribbons?

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[OrangeTJ]

Cool to see that you did this. In reality, then, the performance difference is barely even negligible. Both will get you wherever you are going on the water at pretty much exactly the same time. Since most people don't cruise at WOT, it would seem that these results mean that you might need to open the throttles a hair more to maintain the same speed on a CARB boat.

 

[Gym]

Iteresting report @Mainah. I agree with @OrangeTJ that the 2 or 3 mph difference should not affect your fun factor one bit. Enjoy your boat for what it is, a nice, comfortable, relatively fast boat.

I have met and spoke with Jim & James (father & son) of Long Lake Marina. They run a nice, honest, family operated marina. I'm glad they took the time to help you to analyze thè delta between the models. They went out of their way for me also when I was searching for a boat.

 

[Rob9550]

I have a CARB AR240 and hit 49-50 with just me and the wife. With all the family today, 4 adults, 3 kids, full tank of fuel and all the food and drinks I got 47-48 all day till the winds picked up. I was scared when I read the CARB threads but now, I don't think there is a difference

 

[Scottintexas]

Thanks for the information, I can't believe you had a dealer that was actually interested in helping you find out such info, Good for them,

 

[Mainah]

@swatski It seemed that the carb model needed 50 to 100 rpm more to maintain 30 mph. Top rpm for the carb model is under 7500. Non-carb models exceeded 7500.

@Gym I would buy another boat from James at Long Lake. Good pricing, down to earth communication, and willing to go the extra mile.

 

[Ronnie]

Great report, I can really appreciate the effort it takes to get and test three boats in one day at two different times.

I was boating with @ ajohns (can't seem to locate him here now) in 2013 when his carb (California Air Research Board) 242 Ls was new. When we did a top speed run with three on board each and a full tank of fuel, he was pulling away slightly when I was at 47 mph but think I had more gear (maybe 100 to 200 pounds) onboard in the form of tubes, mods etc. That experience convinced me that although there is a difference in HP between the boats the actual performance difference is almost unnoticeable and not worth worrying about. However, I would still be upset if I was sold a carb boat thinking it was non-carb but only until the first great day on the water on it with my friends and family. It sounds like you've come to the same conclusion. I wouldn't worry about replacing sensors or cats if I had a carb boat only because I have read any posts where these things were replaced yet ant carb boats have been around since 2013.

What I do find interesting is that 2016 boat performed very much the same as the older boats even though it is a little longer (by 6") and I suspect heavier with an integrated keel and sound more sound deadening material. I'm not sure of the X is the model where the Bimini is always deployed but if it is that should have made it slower as well right?

 

[Nick Hughes]

I too unknowingly bought a CARB model. I realized this as I was investigating why I couldn't hit even the mid 40s when on the boat alone. Long story short, i think my speed issues are related to: wet slipped boat is always dirty, 1300 ft elevation, always hot and humid as F this season. Anyways, 44 and 7000 RPM is all I can do right now, I have no adjusted the throttles yet, always too many people and too rushed. I have a lift reserved for next year and plan to add throttle body spacers. But regardless, I emailed my dealer about not being happy about this disclosure and this was his response:

"My store manager and I just got off the phone with Yamaha Corporate and they said, they send California models to all states depending on what inventory they have and production schedules. We do not actually hand pick which boats we receive we have to take whatever they send. Yamaha also says that the California models have been tested and they are not any slower in fact it costs them lots of money to make a California boat over a non cali boat and you get a cleaner running boat out of the deal for no more money. They feel that there is something else that is going on."

 

[swatski]

I too unknowingly bought a CARB model. I realized this as I was investigating why I couldn't hit even the mid 40s when on the boat alone. Long story short, i think my speed issues are related to: wet slipped boat is always dirty, 1300 ft elevation, always hot and humid as F this season. Anyways, 44 and 7000 RPM is all I can do right now, I have no adjusted the throttles yet, always too many people and too rushed. I have a lift reserved for next year and plan to add throttle body spacers. But regardless, I emailed my dealer about not being happy about this disclosure and this was his response:

"My store manager and I just got off the phone with Yamaha Corporate and they said, they send California models to all states depending on what inventory they have and production schedules. We do not actually hand pick which boats we receive we have to take whatever they send. Yamaha also says that the California models have been tested and they are not any slower in fact it costs them lots of money to make a California boat over a non cali boat and you get a cleaner running boat out of the deal for no more money. They feel that there is something else that is going on."

@Nick Hughes I agree a clean hull may help with speed, but no matter how dirty, it does not explain 7000 RPM max...

Call me crazy, but I actually kind of like what the dealer/Yamaha are saying, and in light of @Mainah testing here - I no longer feel that CARB designation is a major performance issue at all. On the flip side, I think it is conceivable these boats will retain value better than non-CARB ones (california air resources board that is) shall any future environmental protection regs limit the use of non-cat boats.

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[Mainah]

@swatski While future regs may entirely prohibit manufacturing of boats without meeting certain emission standards I highly doubt that they would prohibit use nationwide as that would make over half of the boats on the lakes near me unuseable. I think it may be more of a grandfathered type thing with some states being more restrictive than others.

 

[swatski]

@swatski While future regs may entirely prohibit manufacturing of boats without meeting certain emission standards I highly doubt that they would prohibit use nationwide as that would make over half of the boats on the lakes near me unuseable. I think it may be more of a grandfathered type thing with some states being more restrictive than others.

I agree entirely. Just like 2-strokers. Still legal, even though "a small number of cities, counties or districts have adopted ordinances on drinking water reservoirs that restrict or ban the use of high emission, carbureted or electronic fuel injection (EFI) two-stroke marine engines" (excerpt from CARB).

But, the environmental awareness could shift, and it could shift fast. In which case the CARB four stars could look like money!

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[Mainah]

Throttle adjustment is a quick and easy way to make sure you are getting true WOT and will take less than 5 minutes with two 10mm open end or line wrenches. Procedure is in the printed owners manual.

If the cables are too "lose" they will not be able to turn the aps/tps to its stop and you will not get full fuel and air flow. I had to adjust on my boat right when I got it. If one does the thottle drop fix (I did and love it) or installs perfect pass you will need to repeat cable adjustments. If you have an e/x series there is not anything that is user adjustable because there are no throttle cables.

 

[Nick Hughes]

Throttle adjustment is a quick and easy way to make sure you are getting true WOT and will take less than 5 minutes with two 10mm open end or line wrenches. Procedure is in the printed owners manual.

If the cables are too "lose" they will not be able to turn the aps/tps to its stop and you will not get full fuel and air flow. I had to adjust on my boat right when I got it. If one does the thottle drop fix (I did and love it) or installs perfect pass you will need to repeat cable adjustments. If you have an e/x series there is not anything that is user adjustable because there are no throttle cables.

I just haven't had a good chance to do it, i will make time this weekend. Wouldnt it be odd that both engines max out at almost exactly 7k?

 

[Mainah]

@Nick Hughes Perhaps odd but I have seen two boats fresh from the dealer where they needed adjusted. Perhaps the cables relax after being installed and used a bit. Also no idea if the resistor in the aps/tps is single or multi conducter which would be the difference between progressive and linear output. Also no idea if computer reacts progressively or linear to the resulting output voltage. Lets assume a 5 volt 10k potentiometer with single conductor from the reference voltage. The last x percent of movement could be a y percent change in output voltage to the wiper (standard progressive type).

Ok I digress on the geek speak. I am certainly interested if the cable adjustment helps for you or others.

 

[buckbuck]

Putting the performance issue (non-issue) aside, is there any benefit to having a non-CARB boat from the maintenance perspective? I am thinking about @Tad Steinberg who has an O2 sensor problem. Do the non-CARB boats have O2 sensors?

 

[Rob9550]

Throttle adjustment is a quick and easy way to make sure you are getting true WOT and will take less than 5 minutes with two 10mm open end or line wrenches. Procedure is in the printed owners manual.

If the cables are too "lose" they will not be able to turn the aps/tps to its stop and you will not get full fuel and air flow. I had to adjust on my boat right when I got it. If one does the thottle drop fix (I did and love it) or installs perfect pass you will need to repeat cable adjustments. If you have an e/x series there is not anything that is user adjustable because there are no throttle cables.

What is the "throttle drop fix?"

 

[Mainah]

Throttle drop fix courtsey of @Speedling
https://jetboaters.net/threads/throttle-dropping-check-here.299/page-4

 

[Tad Steinberg]

Putting the performance issue (non-issue) aside, is there any benefit to having a non-CARB boat from the maintenance perspective? I am thinking about @Tad Steinberg who has an O2 sensor problem. Do the non-CARB boats have O2 sensors?

@buckbuck
If you look at the parts breakdown on the yamaha site for the non California "CARB" boats there is no O2 sensor to be found on the electrical schematic. I looked and looked and looked (because I didn't think I had a "California " boat). You only see that sensor on the CARB engines.