# 1989 yamaha 175hp 2 stroke



## Irishboi81 (Apr 17, 2012)

ok so i have a 1989 yamaha 175hp 2 stroke but i can not get it to rev up more then 2300 rpm so i can only go at half speed. does anyone have any ideas of what i should check? already had prop rehubbed carbs cleaned twice replaced all spark plugs and replaced the neutral safety switch...any advise would be appreciated thank you


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## feelin' wright (Oct 7, 2007)

Clogged Water seperator would be my first guess. Also fuel hoses could cause this issue.


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## lastcast (Oct 12, 2007)

I would try to use a 5 gl external tank. Might cut your troubleshooting in half.


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## TheCaptKen (Mar 14, 2011)

So at 2300 rpms, what does it do? Does it fall on its face and die or does it just not go any faster? You have to give more clues to this puzzle if you want any kind of educated answer.


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## Irishboi81 (Apr 17, 2012)

it does not go any faster it only reaches half speed but it does go at half speed pretty well


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## Deeplines (Sep 28, 2007)

Get with Kenny. I personally believe it is a cheap fix. I think it is one of your sensors, oil or water. Kenny will know or you can google it it should tell you. It's a built in safety feature. Most likely water. I believe the oil feature will not let you get over 1200.


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## Irishboi81 (Apr 17, 2012)

well anyone that wants to try to help i'll give you my address in "PM" and i will be working on it saturday after 630 pm


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## Deeplines (Sep 28, 2007)

Gnostic likely you haven't ran it so the engine should be cool now. Go outside and run it and see if it will go above 2500. If it does then your motor is running hot. Your audible alarm may haves failed once you didn't mention any alarms. 

Not for sure if you can bypass that sensor or not. Give it a try and see if the motor will go above 2500.


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## TheCaptKen (Mar 14, 2011)

Don't think its going to be an overheat problem. Not really sure if that engine had the SLOW mode in 89. Its not a fuel problem because the engine isn't dying. Check the timing arm on the starboard side of the engine and be sure its moving forward when you advance the throttle.


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## feelin' wright (Oct 7, 2007)

TheCaptKen said:


> Don't think its going to be an overheat problem. Not really sure if that engine had the SLOW mode in 89. Its not a fuel problem because the engine isn't dying. Check the timing arm on the starboard side of the engine and be sure its moving forward when you advance the throttle.


Ive got a 90 150 and it will go into RPM reduction mode if running hot or out of oil. I do not believe that it will go over 1200 RPMs if it is RPM reduction mode. Atleast that is the way mine works.


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## Deeplines (Sep 28, 2007)

feelin' wright said:


> Ive got a 90 150 and it will go into RPM reduction mode if running hot or out of oil. I do not believe that it will go over 1200 RPMs if it is RPM reduction mode. Atleast that is the way mine works.


Yea, I had 89 130's. 

Trying to remember where the sensor is. I'm want to say if you look on the block you will see it. Wires will be coming off of it and the sensor is inside. Seems like the is something else though that is easier to get to, which is what I would check 1st.


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## Irishboi81 (Apr 17, 2012)

i was told to check the throttle linkage how does that sound?


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## Deeplines (Sep 28, 2007)

I was 2x checking the info I gave you. The Thingy in the motor is the thermostat. Lol!!!
Also found out, I didn't know this and it has never happened to me, but check your connections. Battery and motor. Didn't know that that would make it go to reduction mode.

Is your pee water hot as it comes out the engine? If so it's overheating some where. If oil is good then it's your thermostat or heat sensor. Far as I know these are the only 3 things that will put it in safety mode.

Does the motor run rough when it gets above 2000rpms? If so it's not the linkage, it's getting plenty of gas. It's running rough because the system is shutting things down to protect itself.


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## Deeplines (Sep 28, 2007)

By the way, thermostats are easy to change. It looks just like the car thermostat but mine was one the side instead of the top.

When I said Hot I mean hot. Motors go into safety mode at 205. This is the reason you should be able to rev it past 2500 when you start it up.


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## Irishboi81 (Apr 17, 2012)

she runs smooth and she revs above 2300 when not in the water and not on a load so i dont think it is the safety thing you were mentioning...fyi try to dumb things dont for me a bit because this is my first boat and i have not had her out in the water while in my possession just on test drive


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## Deeplines (Sep 28, 2007)

So you can rev it to 3500 out of water?


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## Irishboi81 (Apr 17, 2012)

yeah


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## bonedaddy (Sep 8, 2008)

Its your boat but I would highly recommend taking it to a certified Yamaha mechanic, it will save you time and money. I would not be reving the motor up on a hose. If you don't have the manufactures manual I would get it if your doing the work!


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## Irishboi81 (Apr 17, 2012)

yeah i have it it came with the boat i haven't actually had a chance to do anything to it yet i am just trying to get some ideas of what could cause it and i am in no hurry to get it fixed it still goes fast enough for the bay


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## oxbeast1210 (Jun 21, 2010)

I'm with bonedaddy depending on what the issue actually is you could be doing permanent damage too it.. were just trying to help you out . I understand if you don't have the money to spend on a mechanic or some other circumstance but replacing your motor will be far more expensive....


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## Irishboi81 (Apr 17, 2012)

i appreciate any help y'all can give me and i will not do anything that i can not handle. and thank you for the advise


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## Deeplines (Sep 28, 2007)

I'm along with everyone else. Take it to a mech. aka Kenny. 

I can't tell from what you are posting to help you I guess. Plus when trouble shooting you awesome that others things have been done.

You have said you have checked your fuel system, spark plugs, carbs, pumps, and you can go over 2500 RPM so it cant be your safety mode. I'm awesoming oil is in the motor tank. 

I have no clue if it runs rough, above a certain RPM so can't judge that. My manual I had was a great tool but like folks said. better to take it in then tear it up. I cant even tell if it is running hot. Wish I was home and I would help you. 

Really sounds like an easy fix though.


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## Irishboi81 (Apr 17, 2012)

getting it fixed by a pro as we speak


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## oxbeast1210 (Jun 21, 2010)

keep us posted on what was wrong please

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## Irishboi81 (Apr 17, 2012)

turns out it was the carbs ,,apparently the"PRO" the previous owner brought her to had no idea what they were doing she is working great now according to the mechanic... and now is a good time to add a mention of his name::: Steve Kelly 850-341-3003 he was friendly honest and kept me updated on the status during the repairs


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## Irishboi81 (Apr 17, 2012)

going to Crab Island this weekend woo hoo!


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## Deeplines (Sep 28, 2007)

Good for you. Glad it wasn't a power pack issue.

So was it the high speed jets or just water in the bowl? Did he tell you?


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## Irishboi81 (Apr 17, 2012)

it was not rebuilt properly and some of the jset were clogged


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## Irishboi81 (Apr 17, 2012)

Jets*


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## oxbeast1210 (Jun 21, 2010)

dang glad you got her running good! 
enjoy your new found power !

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## SoCal619 (Nov 18, 2011)

This might sound dumb, but make sure all of your sparks are firing, I had a buddy whose outboard would only get up to half speed at about 2800 rpm's. He pulled all of the plugs and found that two of them were fouled. Replaced all 4 and his outboard was back to running like a top. Most 2 strokes can still run on only half of their cylinders. That would be my first step seeing as outboard spark plugs are pretty cheap and if thats the cause than its a pretty easy fix.


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## SoCal619 (Nov 18, 2011)

nevermind my previous post, I failed to read the entire thread and just responded after the first page, anyways, glad you got her up and running.


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## RMS (Dec 9, 2008)

Doesn't surprise me about the carbs, I have two of those older v-6's.
The carbs are a good bit different than the American motors of that era.
It took me a few tries to figure them out.
I had to soak the float bowls against Yamaha"s recommendation to clear some passages that were clogged. 
Plus, the mixture screws adjust air rather than fuel, which trips some folks up.


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