How a seadoo rotax engine works

This video I explain how a seadoo rotary valve engine works. And upcoming projects.

[@7771ham]

This video should be labeled “how to be an awesome dad” lol

[@OcarinaN64]

Great video. I love your helper. My neighbor’s 4 year old loves to “help”with our projects. He often brings his little folding chair and just watches us work, all the while asking every question that enters his head!

[@bhoehn24]

Thank you

[@TheMdryan]

Good stuff. Thanks for sharing. I used vinyl sign skin and a blow drier to rehab my Seadoo Sportster seats.

[@kwillis623]

Thanks for the helpful video. I am working on fixing up a 1995 seadoo xp with 717 dual carburetors.

[@rayjones3212]

How very interesting. I was curious as to how it all works and your explanation is very clear to me. And of course, your "little helper" is just "darling!"

[@bhoehn24]

Thank you very much

[@bradstringer4830]

Hey Captain I really like your videos your explanation on how this engine works is helping me so much and I thank you for that keep the awesome videos coming GOD BLESS

[@terrencemclaughlin3241]

Thanks, very informative, well explained,great job!

[@krongetnotzy4121]

WOW. Had no idea those head bolts could snap like that. It could be a game changer for this seadoo I just bought for $100. Thinking it would be easy to fix.

[@ZachLorge]

Thanks for the video! Learned lots

[@jeffb8562]

Rotary valve is one of the most innovative things to hit 2 stroke.

[@Gueromessi10]

Thank you. Buying a 1992 seadoo xp with 580 trying to understand these rotary engines and how they work.

[@terrencemclaughlin3241]

Helped a lot , thanks!

[@adamwing9301]

get rid of those grey Tempo fuel lines! all of them! they goo up with the modern ethanol fuels and gums everything in the fuel system. a tip for removing the stuck screws, use PB blaster and impact screw driver and replace with allens or torqs head for easy future removal

[@joshhogge6222]

@@nightspeed4819 gtx

[@adamwing9301]

also, there are a few different companies that make vinyl wraps for these boats, could be an alternative to paint

[@woodyssawshop266]

Great video Im thinking of getting into sea doos, Im use to tearing down ski doo's. Thank You!

[@hectorrodriguez3032]

Wilmington Ditch Divers hi and thanks for the video I have a question if I'm getting to much oil while trying to turn it on thru the spark plugs what is the cause of this

[@bwingfield2]

It was the chocolate bar break at 4:08 that did it for me. Reminded me immediately of my daughter thas 5 rn. great explanation btw.

[@joemekli2328]

Good video. Retired F/F from Ontario. Love the car- interested if u ever thinking of letting it go

[@JC-gw3yo]

Yes keep those helpers involved. With any luck, all you will have to do is point...and supply candy bars

[@bobeden5027]

During the installation of the OEC direct fuel injection system, whilst mapping the engine on the dynamometer I managed to get 748 kw out of the 800cc twin cylinder engine. Lasted only a few minutes before the engine exploded but it was nice to see how far you can push them. Special tuned exhaust with computer controlled water injection ports to control scavenge return pulse. I enjoyed my time in the TEST department, blowing up engines! haha!

[@andredesouza9767]

Great video !!!!!!! Thank you !!!!!

[@jseamix416]

I do small things in 50/50 antifreeze. High temp but not boiling.

[@mousearebec]

Bridgesone Motorcycles had a rotary valve engine. I had a Bridgestone 60. My friend had a Bridgestone 175...... twin cylinder. That was 1965

[@thomasmaloney8475]

you the daddy...... thanks for showing me how the two stroke works

[@scottiemanners]

So I put RV antifreeze in the engine block to winterize like the manual says and let the antifreeze sit in there over winter (just bought a '93 on FB). I did however turn the shaft to turn the valves so I got antifreeze under the pistons. Is that ok? Or should I drain that when I start it in the spring?

[@grahambate3384]

Gr8 video

[@richie2dicks468]

Do both carbs have an idle screw or just the one carb closest to the rear of the ski?

[@rw7051]

How does the mixture get from below the piston to above the piston? I didnt know any of this before.

[@RandalPenman]

Really helpful. Thank you! I don't understand how the crankshaft is lubricated. Mine is the reed valve Rotax 377 with oil injection. If the fuel & air mixture goes under the pistons, would it not surround the crankshaft? And, would some of it not go into the impulse line driving the fuel pump? Is that damaging to the diaphragm? Another video I saw indicated that the impulse line to the fuel pump should be dry. Any additional insight appreciated.

[@ct1762]

the oil is mixed with the fuel and pulled into the crankcase, lubricating the rod bearings (both big and little) . the center, upper and lower main crank bearings are fed usually by an external line directly from the same process with check valves to be sure its constantly getting fuel/oil mix. whole piston/ring assembly gets its oil this way as well. the fuel pump pulse line powers the pump diaphragm, which is sealed off from the other side of the pump that is wet with incoming fuel. the pulse/power side of the pump also has a check valve to prevent blowing diaphragm out at higher speeds.

[@dawsonmacie6984]

Hey man i enjoyed your description. Cool stuff. Thanks. Have you heard of goped scooters? Im into that stuff. Good for your kids in a few years. ......I subscribed

[@RAMFORCE1]

I am from Costa Rica and I am thinking to buying a Speeders BPR 150 with 2 75 HP. The owner say is a 2003 but no sure, one engine is to much wite smoke, so I wander how much will costo a brand new or fully well done refurbished engine to replace just in case. Thanks for any help

[@Imwright720]

I had a friend who was a engine mechanic. He would heat the bolt and cool it with ice cold water . He claimed it almost always worked. The sudden temperature change would break them apart

[@bhoehn24]

I recently got a inductive heater which works awesome. I'm going to make a video about it soon

[@bullfrogzbodyshop]

Do you rebuild these motors? Im thinking about buying this guys sea doo sportster,& 1 of the 717's is bad. Wondering whats the best thing to do here, just buy 1 thats rebuilt or have someone thats knowledgeable rebuild the 1 I've got. Any help from yourself or anybody else is much appreciated. Im a boat noob lol.

[@ziggyr9746]

Hey I want a chocolate bar too!!!

[@TEKKKNO]

I did work on many outboards but a friend brought me sea doo bombardier 2 cylinder needs repair, ive idea bout rotax engines but never work on one before the issue is electric

[@qafmbr]

So instead of an intake manifold, the gas/air mix is under the piston, wow that is different!

[@oneeyedrone4293]

QRFMBR that’s a proper 2 stroke, all large Diesel engines generally run 2 stroke into the crankcase. Lubes up the crank since there is no oil on the crank like a normal 4 stroke. Trimmers and other small 2 strokes have a lubed bearing so they may not dump it into the crank case.

[@billyater1880]

I have two bombardiers both are1997 one is a gti and other is gtx and the pre oiler is broke can I bypass it

[@jameslemmon6148]

What r the bare minimum u have to have to fire a older rotex like the one u have here??

[@jameshunt8285]

Excellent video .. this may be off topic, but does anyone know why on my 1995 XP that I just bought has oil pissing out the exhaust, runs great, the machine sat for 3 years. thx

[@stevendecker8608]

I heard on another video that if you leave it sitting too long, the oil from the oil reservoir will fill the cylinders and could actually make the engine non-operable until it is flushed out.

[@bobeden5027]

Rotary Disc induction engine.

[@trdrockwarrior_sport4432]

say bro the reason why im watching your vid i attended wyotech for the moto mech and im thinking on moving to the philipibes to start a bussiness ill keep it quiet are the jet skies moderately easy to work on? whats the common prablam they have?

[@leroylandin1874]

TRD ROCK WARRIOR_SPORT easy to work on....I'm not a mechanic but I can service my sea doo

[@CampingDad247]

so the circle thing is like a reed valve type of thing lol

[@shanegreen1327]

I'm getting oil up into my intake where the spark plugs plug in, When I went test to see if it had compression he shot oil up through the spark plug whole! What would be the cause of it having so much oil coming through there? Is there some type of gasket that is blown you thing or could it be the piston rings? The oil shoots up like 5 ft so it has tons of compression

[@bhoehn24]

There's 2 ways you cam get oil in your intake. 1 your oil injection pump is over feeding or 2 the seal on the bottom end around your crank is bad. There's 2 oil lines that use oil from the tank to lubricate the rotary valve shaft. If you disconnect the oil pump and run premixed fuel and it still does it, then the seal on the bottom end is bad.

[@allischalmers7030]

If you find out please let me know mine just did the same thing

[@GearheadRob319]

the engineering that went into the rotax rotary valved motor are the reasons cc for cc the rotax motors ruled. and still doo.

[@stronglifeframinginc]

Hey I'm having hard time start 2005 seadoo gti , It has a clunk sound to it when. A try , What it found be ?

[@opossom1968]

would a rotary engine be good in a PCW like this, the rotary is light and compact and seems to me it would be very good in a jet drive application because of the high RPM the rotary engine runs at? i have often wondered why there are no rotary engines in PCWs. can you offer any ideas why?

[@garyweber4333]

the easy answer is pollution in the lake 2 strokes use biodegradable oil

[@TheFlick175]

Snowmobiles experimented with rotaries back in the 70s. Lubrication of the apex seals had not been solved yet so they were unreliable from what ive read. Shame they never had a chance to use them with the improvements that mazda made in lubrication system.

[@jprism1]

1994 Sea Doo GTX 657cc - While rebuilding the top end I discovered several head & top bolts were broken. Is there a good place to order new bolts? Really enjoy your videos!

[@bhoehn24]

Sorry for the late response. Those bolts break constantly no matter what you do. I get my bolts from McMaster carr.

[@jprism1]

Hey thank you so much. Your reply time was great and so far no one else replied at all.

[@richardparke6932]

I have questions. Is there a way to contact you? I have an oil leak and want to take things apart.

[@gupsonguerrier5432]

Hi i have my sea doo challenger twin ingine but it keep cutting the spack plug

[@gupsonguerrier5432]

What's costs that? Plz

[@ZZPxFTW]

if there is enough blow-by to allow the fuel/air mixture to pass from under the piston to the top, how is the engine even efficient on its power stroke?

[@rockiemountin7535]

This is a 2 stroke engine there are ports in between the cylinder and block wall that allows the fuel oil mix to get from the crankcase to the inside of the combustion chamber when the piston is on the down stroke ,there is no oil in a 2 stroke lower it’s lubed with the fuel oil mix

[@ZZPxFTW]

@@rockiemountin7535 yeah I understand the basics of a 2 stroke... He never mentioned a transfer port or anything @1:38 so I assumed what he was explaining was blow-by.

[@laxref69]

I have a 1998 Seadoo Gtx Limited and I think the fuel mixture is to rich but i dont know where the adjustment screw is so i was hoping that you could help me out thanks

[@bhoehn24]

Their under the the carbs. Very hard to get too. They have at t handle on it so you can either use a flathead screwdriver or by hand

[@bhoehn24]

Under the carbs is the idle fuel adjustment and on top is the high speed adjustment

[@arlothompson6576]

You tube is trying to drive us crazy with ads, so we'll buy their 12 dollar a month plan... No way, Jose'!

[@gabby5713]

After boiling water dip do a DOT 3 brake fluid dip

[@AlsermoRivas]

What's the name of the housing that goes with the

[@unfilteredthoughts2004]

Can this engine be upgraded to perform better lol I have a 94 seadoo xp

[@bluej3608]

I have a 99 seadoo spi and I always let off the gas when I hear the drive lose water to keep the rpms down... am I ok to keep on the gas as long as im not completely airborne?? its my first pwc so Im kinda new to the whole scene.

[@bhoehn24]

Yea you'll be fine they have a built in rev limiter. It won't harm the engine.

[@bluej3608]

@@bhoehn24 oh cool thank you, one more thing, the shaft seems like its vibrating when it starts getting higher up in rpms, do you know what this could be?

[@OBrienProductionsHailey]

What kind of things do you want to look for when you buy a Sea-Doo Rotax Jetske

[@bhoehn24]

The best to look for is the XP. It has a lot of options. It comes with VTS which trims the ski out. But is unstable with 2 riders. And has more hp. For comfort I'd go with the GTX seats 3 is quick and has reverse

[@kellyaraujo273]

@@bhoehn24 I have the Same engine in a GTX and it has been a great ski...... until today, I live in Brunswick Georgia and my ski has water getting into the magneto side cylinder... front cylinder..... is it possible that the exhaust has water intrusion.

[@bhoehn24]

I doubt it's from the exhaust. Probably the jug or head gasket. If it were the exhaust both cylinders would have water in it

[@kellyaraujo273]

@@bhoehn24 Makes sense, who would you recomend to buy the parts from.

[@kellyaraujo273]

@@bhoehn24 And I also would like to purchase a shop manual.

[@schecterguy69]

I see this is an older thread,but hope u can help me. Just picked up a 1994 Sea Doo Explorer 5820 with the 650 cc ROTAX engine. It is dumping oil super fast into the crankcase. You can literally watch the tank level drop. Do you think this will be a valve seal problem or an oil injection pump problem ?

[@bhoehn24]

If your not seeing it in the hull or around the engine then its probably leap from a seal in the crankcase. Is it smoking real bad and fouling the plugs

[@schecterguy69]

Yes, it fouls plugs right away and smokes bad

[@Robloxqueenisme]

my jet ski ondy does 20 mph and only opens up sometime while in the water i replaced carbs and sparkplugs any idea on whats hoing on

[@Robloxqueenisme]

theres nothing stuck in the propellor or anything I dont knoq whats going on

[@haroldgentry7514]

@@Robloxqueenisme check the compression

[@jerrymalone8370]

Check the high speed jets. Maybe they are clogged.

[@blindabinda1234]

Is a 99 speedster with a trailer and cover that's only been in fresh water worth 1800?

[@bhoehn24]

It all depends on condition. But if it has the rotax engine then it should be worth that. In 2000 the switch to the v6 mercury engine which is total garbage

[@blindabinda1234]

Capt n B garage it's got 220 hp. I believe it has 2 110 hp 2strokes.

[@bobbylong2202]

Lol love how the kids want to be apart of your projects

[@jeremyvelez6212]

Where can I get a set of those Mookinis lol

[@StevenVigus]

Nice explanation! I detect an accent. Are you from Texas?

[@haleyy68]

Texas?? LOL Maybe Jersey or New York.

[@MrCpsloco]

Steve Vigus 🤣🤣🤣🤣

[@briannotafan3368]

i raced comet B-bombs in my karts in the 70s kinda simmeler

[@briannotafan3368]

i spell worth a crap

[@sergiopalma3329]

Buenas nochs como alterar las revulucines de el motor

[@SouzaxSouzax]

New subscribed here, i have questions sir Hopefully you can help me to figure out, I have a 1995 seadoo Sportster jet boat single engine 657 the problem what i have is it take a little longer to start up every time , i changed the spark plugs already but nothing changed

[@treysteinberger1457]

*when they do work!*

[@jessebejarano7146]

I have a 2002

[@cvcalitos]

do these engine use oil to Lub the bottom end ?

[@bhoehn24]

It's a 2 stroke. So the oil that mixes in with the gas will lubricate the bottom. It doesn't have a oil pan like a regular 4 stroke engine. There's no oil to change.

[@cvcalitos]

Capt n B garage my engine had some old oil in there. I tilted the engine and out it came ... do you think is a bad idea to delete oil injection sys and run pre mix I’m using these Engine in a go kart project.

[@xtune5731]

carlos v how are you going to cool the exhaust

[@victorugalde2000]

Hi captain b I don’t think I have pressure on my fuel pump on my 96 gtx seadoo can you help me

[@bhoehn24]

Your fuel pump is mounted on the side of carburetor. What makes you think you don't have pressure

[@lunaman98able]

I have a a similar issue, how much pressure comes from the pulse line? Can it be increased? We rebuild the carbs but cant get fuel in the carburetor. Help explain psi needed for pump to work . Thanks.

[@8ackbar]

it's Mikuni carbs

[@harrymananus5380]

8ackbar zucchini carbs

[@EvoPortal]

The only problem with the rotary valve is that wears out WAY soon than anything else in the engine. The reason why they stopped using it...

[@bhoehn24]

Great point

[@OcarinaN64]

True, but replacing a rotary valve beats sucking up a broken reed IMO.

[@khubbard1.8t61]

There are three reasons BRP went away from R/V engines. One: It can't be run backwards which is what Ski-Doo needs for the reverse system on their snowmobiles. Two: Reed valve technology caught up and diminished the performance advantage of the R/V. Three: Cost to produce versus a reed valve engine.

[@joshhogge6222]

I have 2 97 gtx and one of them will run for 50 yards and then it goes into some sort of limp mode and I kill it and the process goes on 50 yards and limp

[@bhoehn24]

It seems like some kind of fuel issue. Have the carbs been cleaned and does it still have grey fuel lines

[@joshhogge6222]

@@bhoehn24 yes carbs are done I have a voltage reg coming

[@joshhogge6222]

@@bhoehn24 has the gray lines

[@brandonnorris1026]

I changed the video

[@ryantoomey611]

Weren't the rotary engines also used in the Mazda RX-7?

[@bhoss7133]

Ryan Toomey yes. But this is not a rotary engine. This is a rotary valve engine. Very different.

[@vspd303]

So is this motor something to stay away from

[@intotheadventure2592]

Nah they are fun as hell

[@jessebejarano7146]

Why in my getting water out of my spark plugs

[@bhoehn24]

It could be a couple of things. A head gasket or restricted exhaust. When you run it on the hose make sure the hose is not on with the engine not running otherwise water will back up

[@matthewsykes7370]

Could use your knowledge

[@remserviceukraine]

Возможно будет кому полезным. Занимаемся лазерной резкой. Наглядное видео процесса. kzbin.info/www/bejne/bGK2aIaLjdiirrs

[@briannotafan3368]

thats why god made never seaze grease works in a pinch

[@brianemery8945]

Mookini carbs. Lol

[@michaeljohn8905]

hey im from Long Island and that sounds bout right lol JK.

[@Plastickmat]

Haha Bikini Carbs

[@tackdriverCA]

The rotax two stroke is flawed. That damn geared shaft is a fail point. I’d rather change out reed valves

[@StansWorld]

Hey need a intake resurfaced Ill do it for $50 just holler stans world

[@zachariaocoleakorimo5673]

Dnt he kinda look lyk mista beast

[@CONTACTLIGHTTOMMY]

Mikuni.

[@jettelo]

Don't u say white powder 😉😅. Be nice Dad

[@projectthetruth385]

What is your opinion of the powertrain in this boat? www.scarabjetboats.com/us/boat/255-open-id jetboaters.net/threads/rotax-powered-jet-boat-information-repository.10156/

[@jimhughes2430]

Mookini carbs huh? Lol

[@gilliamconst]

Soak them in coca cola

[@gauntlett8764]

Seadoo builds a lot of garbage