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Finally PERFORMANCE MODS For Yamaha 1.8 Motors

JetBoatPilot

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Hey Guys,

I think we have our first true performance mod for the 1.8 liter motors!

Riva Motorsports has released a high flow K&N Air Filter for 1.8 Liter Yamaha Engines. I don't have performance numbers yet but I know that they spend a lot of time and money getting the fit right.

I don't have a set on my boat nor have I had a chance to hear feedback from any of Riva's customers but I wanted to get the word out to you guys since many have asked about this in the past.

Here is the link to the product in our store.

https://jetboatpilot.com/index.php?id_product=679&controller=product
 

octavio3311

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Very interested to hear your testing results!
 

MikeyL

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And of course from our one of our most favorite suppliers, @JetBoatPilot !

Many Thanks - Great post. More HP = Faster boats !
Mikey Lulejian - Lake Oconee, GA
 

ruztew

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on my old waverunner, MR1 engine, I pulled the air filter off and ran without one for years.... would that be a problem on the 1.8l? The MR1 air filter got saturated with oil when it was overfilled once, so I pulled it off and never ordered a new one.
 

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I am not sure but on the coast I would be concerned about salt air. I assume that the air filter prevents salt particles from getting on the valves. That could be a big problem.
 

Noko

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Anyone have any info on filters to use on the 1.8l if you replace the ribbon restrictor with the Riva ring? I bought some R & D filters but they won't fit. The filters are big blue ones but are too long to fit. I saw a thread here where someone did the mod removing the ribbon and putting in new filters. I thought I read that if you remove the ribbon, you lose the flame restrictor.
 

Britboater

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I had a K&N on my FZR runner, I was told I needed to remove the Ali gauze (ribbon delete) to compliment the filter, I never really noticed any difference, maybe a very slight top end, but when your flat out on a ski, 2 or 3 mph extra is hard to notice.

Maybe with the nature of a boat being heavier, we may notice a difference.
 

ISLANDRACING

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FINALLY??? ...performance mods for the Yamaha 1.8's have been out since 2008. Yes they started as mods for the Waverunners, but many can be carried over to the jetboats.
We just finished a 212x with R&D air filter/flame arrestor, WORX ribbon delete, Riva waterboxes, Solas impellers, Custom IR freeflow exhaust.
 

jcyamaharider

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FINALLY??? ...performance mods for the Yamaha 1.8's have been out since 2008. Yes they started as mods for the Waverunners, but many can be carried over to the jetboats.
We just finished a 212x with R&D air filter/flame arrestor, WORX ribbon delete, Riva waterboxes, Solas impellers, Custom IR freeflow exhaust.

Before and after performance numbers or it didn't happen.... ;)
 

Englewoodcowboy

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I too would be interested in your results Will. I was thinking about the ribbon delete to help at my altitude but needed to source a filter that would become the new flame arrestor point. I think this would be a great package deal... If you need a guinea pig, PM me. I am game.
 

JetBoatPilot

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I will follow up with Riva about the Ribbon Delete.

I guess I should have said finally JetBoatPilot can offer some performance mods. No offense intended @islandracing
 

Ronnie

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I installed the same air filters earlier this year along with the air manifold upgrade / ribbon delete mods. The upgraded air filter acts as the flame arrestor if you remove the stock flame arrestors/ribbons, just like the aftermarket air filters on the 998cc and 1,052 cc mr1 engines do when the stock flame arresters are removed or replaced with velocity stacks (they do the same thing and look similar to the ribbon delete mod).

Personally, I did not see any performance improvement by way of increased Rpms or top speed. I boat at sealevel if it matters and think that I'm already at the rev limit, if any, set by Yamaha. The air filters are nice because they are reusable but they are not suseptible to being saturated with oil like the air filters in the smaller mr1 engines so if your stock air filters for the 1.8 liter engines are fine I wouldn't bother replacing them with these. The ribbon delete was pure snake oil, too me anyway.
 
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Speedling

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Supercharger kit?
 

veedubtek

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I believe @ArmyChief was talking about a supercharger delete as soon as we get back. :p
 

Englewoodcowboy

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Cobra Jet Steering LLC

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I tried a modified air cleaner element on my supercharged s h o and a solas impeller, it really did not make a noticeable difference other than to my checking account but it was fun doing the impeller, NOT REALLY I had to cut the thing and split the hub to remove it from the driveshaft and yes I know they are left hand thread I heated it with a huge torch and built a special driveshaft holder but nothing worked short of a plasma cutter and a cut off wheel.
 

Englewoodcowboy

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Everything I have read on them does not change much if anything at sea level... from what I have read is it is all to improve at altitude to compensate for the thinner air. Not a mod high on my list but something I will look into down the road.
 

Cobra Jet Steering LLC

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the big top end killer here is TEMPRATURE, the higher it goes the slower you go, here our water is about 90 degrees and we loose a lot of top end speed in the summer due to the increase in water temperature, as it cools down our speed goes up dramatically.
 

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To be honest I'm surprised Riva hasn't already redesigned their existing Yamaha 1.8L Waverunner turbo kit to work with the boats. They are the same motors correct? Most of the reworking would be in the intercooler and pipe plumbing, so it doesn't seem like that big of a deal to make a new kit. The issue for them would be demand, which I imagine would not be near as much as the PWC crowd.

Up to 400hp (or 800hp combined for twin engines) would be sweet though!

 
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