Fixing A Yamaha 90hp 2 Stroke Outboard Motor 

I had an impeller in my '08 merc 25 efi that looked like that and it caught me by surprise because I got complacent. And yeah, what you were describing about pieces of the broken impeller winding up stuck in the water tube is exactly what happened to me. I found an entire fin and some small pieces of rubber trapped in there. I was able to work the larger piece out with a small piece of wire w/ a hook on the end of it..and then I was able to flush everything else out with water thankfully. Even with all that, I was still getting water flow through the motor and the tell-tale but it was just a rather weak stream. Very little pressure coming out of it. So that's what initially led me to believe I was fine. It wasn't until I got my first over-heat alarm that I decided I needed to pull the lower unit off and do an inspection. The motor would over-heat if you were idling or trolling around at very low speed for too long. Lesson learned there. Now I replace the impeller yearly when I change the lower unit gear oil. It's my first boat and I had a lot to learn when I bought it...and I'm still learning daily.

Great video thanks. I have an older Yamaha 90 2 stroke with a similar running issue. Thought it was ignition but I have good spark across all 3 cylinders. I was a little intimidated about pulling the carburetors until I watched this video. I’ll let you know how I make out. Thanks again for taking the time to share your knowledge.

I have bronchitis as I'm watching this 4 years after you posted it. I winced every time you coughed or cleared your throat. Thx for great how to videos

Love it! Even good it has a distinct sound. 2 stroke idle. Reminds me of my old mx bike.

Thank you so Much for your expertise I’ve followed you this year and I’ve learned so much from you thank you Boat Guy you are better than the rest on RU-vid

Nice to watch you taking nice care of this power house Yamaha beauty ❤ Many people aren't aware of these cleaning needs necessary for the engine to run and run smoothly.

Your videos are awesome I love learning about the stuff and you explained it well 👍

You did a great job explaining what you were doing!

Man! It rains a lot out there. Good job Eric, good water flow and clean carbs, they cleaned the carbs huh 🤔

Your very good at explaining problems and solutions....thanks

Thanks for taking the time to make this vid!

Excellent Job !!! I love your videos ........ keep up the great work.

i learned alot by watching this. Thanks!

Awesome! Thanks. Try one on same motor. With the reverse gear grinding and not engaging. But it will still go into fwd gear.

Love your content. It has taught me a lot. I know what to ask when buying my first boat.

Great Job!! Looks kind of uncomfortable to work on the floor, but you did it...

I use to have a Yamaha 90 and it’s been around for 20 years, still runs

Love your skills and know how love Yamaha 2 stroke out board

Great vid, thanks. Do you have a vid on adjusting the carbs yet? That would be a big hit :)

I live in San Diego and was looking for a very clean Yamaha and could not find one. I did see them in Florida but not around here. I did find a beautiful Yamaha 85 with less then 85hrs. I've put 1100 hrs on it and it runs perfect. Really the only difference is I mix the gas and oil.

I have the same motor. It is very hard to start after sitting a few days. After getting it started it cranks and runs great all day.

Best engine ever, and not even that thirsty. At WOT not much difference to modern 4 strokes, but with lower rpms obviously some difference.

You’re videos are damn cool man

Good buy and replacement of the pump. Crikey it’s raining!

Hello, I have a 1992 yamaha 50hp 2 stroke engine, its been sitting for 2 years and i cleaned the carbs yestarday but then it wouldn't start anymore. Needle on each carb is in good shape and moving normal, also the jets are completely clean. The engine did start before i started cleaning the carbs but it was not reving up and it felt like it had low power when going forward.

I really appreciate your videos...Thanks...

Dude can you do a video with more details, Thanks for all the videos man, fantastic job man.

that sounded supper sweet

Are the j plugs better than the surface gap for a 90hp 2 stroke outboard motor

Nice job 👍🏻

Excellent well done love my 90 hp 2 stroke......your up there with Danger Marine....

Great info. I have a question I have a 2001 Yamaha 70 tlra it sometimes overheats when trowling it has a new impeller and does not overheats during normal running. Is there a popit valve on this motor? Any information would be appreciated thank you

I have the same motor I think they're great

Did you have to sync your carbs after reinstalling

My dad always said its important to know how to fix motors on boats cars or anything because it saves big bucks$$$and that's pretty much the truth

haha. You have to be in Florida too, rains every time I try and do anything outside.

So if the previous owner(s) never bothered to replace the water pump impeller I would suspect they never checked or changed the lower unit lube either. I'd highly recommend draining it, pressure check it, and (if pressure checks OK) refill with new Lower Unit Gear lube.

Sounds good , wish I could find a Yamaha 90 to replace my evinrude 70 . But they hold their value so well can't afford one ,lol

I have a problem with my outboard engine, f60 four stroke 2002 that doesn't rev past 2500 rpm on the lake. I clean the carburetor and change sparks plug, fuel filter and new gas line. The top two carburetor doesn't seem to have enough gas. I check the compression on all four cylinders and it all good and have good spark. See what you have for any other idea?

What does an oil leak from the injection system entail? I am seeing the same greenish oil type coming from my Yamaha 85 2-stroke, but have not opened the air intake or carburetors yet.

Hey buddy I finally got me another bigger motor! Got a 55 so boat is scooting and in tiller steer

I appreciate your videos very helpful… what is the part # for that 90yamaha impeller so I can order please

I have a 1993 2 stroke that runs smooth but the rep’s won’t go over 2500. Motor is clean and well maintained. Help needed

I got the same 90, it won't go above 2700 rpm and with a 2stroke (as u know) that's not even the powerband yet so needless to say it's a slug at the moment. I think I'll give this a shot and do a new bulb-hose & filter clean while I'm at it. Thanks for the video so I have an idea what I'm getting into

You're doing great job, my friend! Planning to move to FL soon,I would like to know, areas to live like yours. May I ask you, where is this area you live ?

It looks identical to mine. I think a needle or 2 are stuck in mine and it's dumping fuel all the time except when I raise it completely up. I was gonna do this today but a thunderstorm came lol quite a coincidence. Tomorrow it is. I wonder if your needle came apart and if you got it back together because the little wire things that grab the float were missing when you showed it out, I'm sure you did because it ran great but I had that observation. I appreciate you sir, thank you for sharing your skills knowledge and experience.

Can U make a video please of how to remove the carbs? and reinstall and setting the carb flaps all syn'ed up?? Thk U.

Two strokes are lovely in torque

I have a 2001 yamaha 40hp 3 cylinder 2 stroke autolube. Have problems with the engine "sneezing" and stalls at idle. Noticed a pulsating air sound when engine running, and I found a loose hose between the crankcase and the middle carbourator. The carbourators looks similar to the ones in this video, and the middle one got this "fuel enrichment system" for cold start. Can this loose hose make the engine running bad? And why is it there? Pressing cranckase pressure in the middle carbourator? Thanks for making this videos, now I'm confident to try to do a carbourator cleening if not the engine will run smooth after reconecting the hose :-)

What oil would you recommend for my 1985 90hp Yamaha

Can you do a video on wiring for 90hp 2 stroke Yamaha?

I've got an 09 90 just like that one. When out of the water you can't hear it but once in the water it sounds like a gasket is leaking and going with compression of motor but near lower cowl. Any idea where I should start? Also how do I remove the lower cowl to access the power head bolts

thank u for information I want more vedios

I just got this same engine but a 1999 one and I got it to crank a few times but it shuts off 2 seconds later. I assume no fuel is getting to it. Whats the best thing to do?

Thanks for the videos. Got a question, how do you determine on a water pump that you change just the impeller or do a whole kit? Also are you formally trained on marine mechanics or self taught?

A workbench and a magnetic parts tray would make your life so much easier.

Yam 90 best engine Yam ever made and ive had most. Used these commercial, noisy and thirsty but bullet proof. Wish I could have stayed with them but fuel costs forced me to four stroke.

Dear Mr. Boatguy I have a question. I have a 1982 Evinrude 70hp.I checked the compression on it 2 of them read 135 top and bottom but the middle read 90. I know that doesn't sound good but can you give me an idea of what wrong thanks... And by the way love your videos man watch them all the time helps me know what to look for in a outboard engine I watch you work on many

Had two issues with my 05 90hp, first, the guy who sold it to me didn't mention that the impeller blew up and a few of the blades got all the way up under the head causing random overheating when they sucked up to ports. Took forever to figure that one out. Second, even with flushing motor(saltwater) after every use, it corroded so bad internally that the bottom cylinder wall corroded through. Had water pouring out of bottom carb. Had head rebuilt and sold it and the boat. Now i just ride on other people's boats, that's when their motors aren't broke down. You should have tons of work down here in the Tampa area.

So on the blue tank, there are two fill locations, what is each one for? I assume that the top is either engine or gear oil and the bottom looks like 2 stroke oil.

Hi I know this video is many years old now but I wonder if you still have one of these motors in your workshop. If you do could you send me a picture of the wiring from the stator to the rectifier so I can see what wires go where. I have one that has been botched wiring wise. Many thanks in advance 👍🏻

Legendary Yamaha only Yamaha stand the test of time

I have a 30hp Nissan I just purchased. It’s very hard starting & when it finally turns on . I put it in gear and shakes a lot, engine stumbles and wants to shut off or does shut off. Do you think it’s my carburetor. It doesn’t have a primer to the carburetor just a choke

what size wrenches do you need for lower unit and bolts on inside?

Wow, looks like you are defiantly the guy I need for advice on a motor I just bought. Low hours on a 1993 40hp Evinrude vro. Runs real rough. Sat a bunch of years. If I clean the carbs like you did, Do I have to sync the carbs? or Just put them back together the way theyy came apart?

HI mate l have a 70 yamaha 2001, the same as this 90. What l would like to know is a lot of people disconnect the oil injection and mix oil instead ,probably for peace of mind. Which means if the system fails then you could damage the pistons rings etc. My question is, how do you know if the oil injection is working fine. and that the engine is getting the oil. How can you check this ,tell tale signs that it is not working properly etc.

Let's see it on the water man! That thing outta fly! Good job with the vid, good detail and "how to."

What's a starting point after carb clean for adjustment screws?

handy guy. thanks for the video.

i like your work , i have a 50hp 2 stroke mercury / just rebuild my carbs, can not get them to stop leaking , i put new needle /float/gaskets still can not get them to stop leaking any help or advice i will surely welcome it .

I have the same one, mine has an issue that it will start shaking when i try to speed up. it runs fine on low rpm but won’t go faster without shaking. Any ideas what it could be?

I have the same motort. Had to replace the impeller because of some broken fins. Your video explained it perfectly. So now I have an issue with boat going into limo mode and the alarm going off when I am at full throttle and 75% trim. Didn't have this problem for the last 2 years. I replaced thermostat, thermostat sensor, new plugs, cleaned oil tank and screens. Haven't pulled the head cover to check on the carburetor. But I might do that today. Can it be anything else. Temp of the heads when the alarms are going off is about 160-165. It will run just fine once I get on plane and throttle down to about 5000 rpm.

nice vid, i see your a Toyota man, good call!

how did you get the main nozzle out of the carbuerator

pissin like a champ!

First off thank you so much for this video, and all your videos. They have been incredibly helpful so far!!! I was wondering if you could show the proper way to clean or change a pcv valve and also an oil strainer for this same style Yamaha 2 stroke please?

Dem Yamaha‘s are great😂

I just bought a 24ft Grumman party barge . It’s my first boat and has a that Yamaha motor. I’ve never owned a boat . It has a chain and piece of plastic when I check the oil . I can’t tell when it’s full . How do I read it or can I change it to dip stick which I am use to. You add the oil through the top , correct. I just ordered a service manual

2007 90TLR yamaha 2 stroke.... rough idle, llloooonnnggg crank to start, miss fires, carbs just rebuilt and spark plugs replaced. When she warms up it stops, what do you think it is?

Sounds mint. Pees nice now too

How long does the engine work if the engine does not get oxygen or air?

Hi, I'm Italian and I always follow your videos, very interesting. on this engine, to replace the gear lever, do you have to remove the thermal block or is it enough to remove the intake manifolds?

Did u replace the gaskets ? Or just clean and reassemble ?

Great video, thank you

How do I get a hold of you? Need help with older engine.

Dude has the fuel cough

How you know what size of impeller your motor need ?

I had the exact same motor, it was a dirty plug fouling beast. It was my first and last Yamaha anything.

I don’t know if you ever done this before but iam just curious but have you ever put a Yamaha big tiller on a Mercury outboard. I saw one done before. And the reason I ask is because the Yamaha big tiller is way less expensive than the mercury. Hope you see this soon. Thanks

Did you sink the carbs when you got finished

Hi mate, l have a question. l have a 70 hp yammy 2001 ,2stroke. Its running fine.l noticed when it was running that the fuel filter on the side next to the oil white plastic container was filling and then emtying and then refilling every say 30 seconds . Is this normal l doubt it, this was when l was running the engine on the muffs at home for about 10 minutes. It does it every time l run it like this. Not been in the water yet since l bought it a few months ago.

Stupid question but I need to replace the compressor on my 90hp 2 stroke where is this located or is it giving a different name (water pump) maybe? It’s a jet also

good video but you can also call the "lower unit" the gear box :) and

I have a 1987 25 merc that has been sitting for a while that I got from my dad. It's kinda special to me but it's not running. I took it to Brydes marine in st Pete florida and they wouldn't mess with it Said it's too old. My thing is it's has sentimental value. May need $2k of work but when I took her out about 7 years ago she ran fast as hell might just drop the cash and have her running again

Ever use a jewelry cleaner to clean carbs? I love mine for carbs with Dawn soap.

I have a 2002 90 horse 2 stroke oil tank is leaking oil runs down side of engine to foot. This happens when engine is just sitting not running. I cant see any visable leaks. I can't find any diagnostics for my oil tank or any instructions to remove the tank.If you could point me in the right direction I would really appreciate it.

how much did the motor cost you in purchase and how much was the parts?

What is the cost of this type motor? Great video, you should be a mechanic.

Do you know why a 2005 Yamaha keep fouling out the spark plugs

I have one like you. f70. How to change the engine oil?