GP1800R #3: Easy $50 Free Flow Exhaust

A quick video of how to do a free flow exhaust on a 2020 Yamaha GP1800r for about $50 without voiding any warranty. This is completely reverseable and doesn't involve cutting any factory parts on the ski like some kits online require.
Running at 3:35.
The parts I used are listed below; If the links are expired just google what I explain to use in the video and you'll figure it out:
Silicone Elbow: www.amazon.com/Autobahn88-Uni...
3.5 45 Deg Pipe: www.ebay.com/itm/3-5-89mm-Alu...

[@nathanielpina6568]

Just FYI for anyone who may own a 2019 FXHO Cruiser. The factory rubber hose coming from the exhaust hull outlet is much shorter than shown here. You will need a longer aluminum elbow. Otherwise the process is just as described above.

[@brandonreese4742]

Lmao I love the way he’s like ah fuck it just start pulling shit out

[@rickwestwood6258]

Hi did it cause any issues with water levels as I see you have now changed to the worx through hull which goes up higher inside the hull under the seat before dropping back down to exit?

[@cactusstudiossouth]

HEY GP! I have a 1996 Yamaha Wave Raider 1100! Useully runs great! But it stalled twice on me out there....installed new Start/Stop Switch Box & new Starter Solenoid! When I jump the Solenoid terminals it cranks over fine! Nothing when I hit the Green Start Button!!! There in No Power to the White Start/Stop Connector comming from the CDI Box!!! Any idea's?

[@ChardyboyMotovlog]

Nice

[@saramesa1277]

I dont want to cut the aluminum pipe like you did, so should I order instead that 2.5 (64mm) Aluminum pipe 45 degree 1'(30.5cm) section intake/intercooler, please let me know if this one would work, thanks

[@ZF5foraWhiteGuy]

The pipe needs to be 3.5" (that is the diameter) the section i got is 1 foot long and cut a few inches off because the 45 angle needs to be closer to one side than the other. If you can find a pipe like this you can do it but i dont think you can without getting it custom made. Its much easier to just cut it with a hacksaw.

[@Scarscape]

Thanks for the video! I am thinking about doing this to my gp1800r, however, I am wondering how well has the silicone elbow worked? I realized most of the silicone pipings are rated for about 200celcius, I am worried if the exhaust gas will get too hot for it?

[@ZF5foraWhiteGuy]

The exhaust is mixed with water from the water box, so in theory, it cant get any hotter than the boiling point of water of 100c.... mine held up just fine for over 100 hours before i switched to a thru hull exhaust for no reason other than me wanting it.

[@Scarscape]

@@ZF5foraWhiteGuy 👍

[@corymiles3860]

You said your on the potomac? I assume the Potomac in southern Maryland?

[@ZF5foraWhiteGuy]

I was. I moved last year. Im in san diego now.

[@bob-a-louannamaria7960]

How is drone??

[@aymane8673]

Does anyone know the difference between a normal riva rear exhaust and a riva free flow exhaust (other then the price)

[@kingmike2121]

Rear thru hull exhaust you have to cut a hole in the hull. Free flow you do not.

[@evaiddripps2253]

Will doing this cuase the engine to run hotter and wil you have to get the water cooling upgrade?

[@ZF5foraWhiteGuy]

It didn't make any noticeable difference to me without a cooling upgrade.

[@FaReFogo]

Not to be the bear of bad news maybe I’m wrong but where is the exhaust pointed at

[@ZF5foraWhiteGuy]

Nothing has changed with where the exhaust exits. You're just deleting the resonators/mufflers between the engine and the exhaust exit. No different than replacing a muffler on a car with a piece of straight pipe.

[@lastfirst7818]

My man said “or however the fuck you say it” haaaaaaaa..

[@SlayerHawkX]

Any problems with the smashed elbow..i done this and the elbow is pretty smashed...sounds good but havent had time to put on lake yet..

[@ZF5foraWhiteGuy]

My elbow wasn't smashed, make sure the tubing is inserted into the elbow as far as possible.

[@SlayerHawkX]

@@ZF5foraWhiteGuy well i actually meant theres a bit of a bend in the elbow to where its not a perfect circle in the tube..just hope it dont restrict air flow..mine looks identical to urs..the pipe i bought from ur link was lots smaller than the one u have ..i didnt have to cut anything..think it was like 11 inches

[@SlayerHawkX]

Or was i suppose to cut?..

[@ZF5foraWhiteGuy]

@@SlayerHawkX on the aluminum elbow i cut one side so the bend was a little closer to the one side like in the video. I didnt cut the silicone elbow. Loosen the clamps and mess with the positioning, the silicone elbow wasnt "smashed" on mine or kinked as im interpreting that. The aluminum pipe was certainly not smashed unless you got one that was damaged somehow.

[@SlayerHawkX]

@@ZF5foraWhiteGuy ​ i done this...works fine..but theres a horrible noise at 3 k rpm and below..i went ahead and got riva stuff.and sounds much better..and believe has much better back pressure...i actually gained a mph or so..BUT IF UR BROKE LIKE I WAS THIS WORKS JUST FINE FYI to ppl out threre

[@jstone1211]

how do you stop water from backing up into the motor when being towed...new guy here...

[@ZF5foraWhiteGuy]

This effectively is the exact same setup as any other aftermarket free flow exhaust. Neither of which changes the principle of why water doesn't backflow into the engine, because water won't flow uphill.

[@jstone1211]

@@ZF5foraWhiteGuy thanks, but water will go rise in level if there is back pressure. I am concerned about flooding the engine if my ski has to be towed. I know this is off topic from your video, which I enjoyed. I was here trying to learn about the exhaust system. Thanks again.

[@ZF5foraWhiteGuy]

@jstone1211 towing or stationary, it wont change the fact that the ski wont sink. It has nothing to do with back pressure keeping the water out... think of it as setting a pool noodle with one end in a pool and the other end on the pool deck, water wont magically move uphill without a vacuum drawing it out. Since the engine is above the water line, there is also no possibility of siphoning... your question has a lot to do with fluid dynamics, however i can assure you, this modification will have absolutely zero impact on the ability of water to enter the engine.

[@jstone1211]

@@ZF5foraWhiteGuy thanks for your reply. I am staying stock for now as I am new to Jet Skis. I did look at the exhaust on my waverunner. seems like water could be pushed up into the water tank in the system. again thank you for your reply.

[@johnh9507]

where did you find the 90 degree silicone different end sizes? back a few years ago i could only find the same size on both ends

[@ZF5foraWhiteGuy]

Link in the description

[@ckpk41605]

Where did you run your vacuum hose for the bov.?

[@ZF5foraWhiteGuy]

T'd into the MAP sensor line. Works fine

[@ckpk41605]

@@ZF5foraWhiteGuy ok. When I did this is has a huge dead spot in the throttle. For now I have just capped the t and it runs fine. Guess I’m gonna try the iat adapter. Or maybe a 2psi spring. Not sure what’s in it now. I have the same one as you. Any thoughts?

[@ZF5foraWhiteGuy]

@@ckpk41605 i believe i used either the yellow or white springs, which arlre 8psi and 11psi. 2psi is too low im sure. You probably have a dead spot because its open at idle or right off idle. So a stiffer spring should fix your problem.

[@dwaynef17046]

Did you notice any performance gains? Top speed increase?

[@ZF5foraWhiteGuy]

Top speed is still limited, I didn't notice much difference other than a volume and tone change. However I prefer to get the supporting mods out of the way before going for power in all of my builds.

[@dwaynef17046]

@@ZF5foraWhiteGuy OK. I've done all stage two except the free flow exhaust and just wondered if it was worth it performance wise. I'm not really looking for a noisier ski but if it gave me a couple mph I might think about it. I saw one guy on KZbin reattach the resonator to cancel out the drone but probably still quite a bit louder. Thanks for the video.

[@ZF5foraWhiteGuy]

@@dwaynef17046 IMO, Id say only do the free flow exhaust if you're also going to do a water box.

[@ronaldsanchez1785]

Where you buy silicone elbow? And what Size

[@ZF5foraWhiteGuy]

Link is in the description

[@ronaldsanchez1785]

@@ZF5foraWhiteGuy Thank you

[@scotthendrickson8509]

How do you like the exogear speakers?

[@ZF5foraWhiteGuy]

Junk. Waste of money. One is completely broken and the other i use as a portable speaker sometimes but its nothing compared to a decent JBL. They basically tacked them on and forced me to buy them. It was a weird altercation with the saleswoman and i eventually caved. She threatened to not sell me the whole ski without them. Because there was a waitlist.

[@harrisboy17]

What speaker setup you got??

[@ZF5foraWhiteGuy]

It came with the "audio package" from yamaha but it was completely pointless. It was just 2 shitty waterproof Bluetooth rechargeable speakers and mounts. Terrible speakers, no bass, could hear them over 20mph and one of them stopped working in 2 weeks so i just took them off. No speakers on it now

[@salvatorem740]

What happened to the vids

[@ZF5foraWhiteGuy]

Haven't been riding or changing much on my ski lately been busy with work. Hopefully get some more time late summer.

[@salvatorem740]

@@ZF5foraWhiteGuy Awesome I got 81mph with the mods you posted!!!!

[@gracie6237]

Dumb idea. The water box prevents water getting in to the engine in case of a flip over.

[@ZF5foraWhiteGuy]

The baffles were replaced, not the water box. The water box is still in place.