Help - Yam 90 2 Stroke Issue - Pensacola Fishing Forum

Go Back   Pensacola Fishing Forum > General Discussion > General Discussion

Like Tree2Likes
Reply
 
Thread Tools Search this Thread Display Modes
Old 07-04-2019, 07:34 PM   #1
Member
Ruby Red Lip
 
Wahoo's Avatar
 
Join Date: Oct 2007
Posts: 96
Default Help - Yam 90 2 Stroke Issue

I run a cheap aluminum Turning Point prop and hub kit. Has worked well for years. She was getting a little dinged up and I replaced the prop and hub a few weeks back. I went a few days ago and hopped up on plane no problem, but about 30 seconds in I got horrible engine vibration / cavitation / slipping... not exactly sure how to describe. I could run around at 6-7 miles an hour, but anything more than essentially idle it would start to slip and vibrate. Didn't sound good. I assumed prop or hub issue even though I didn't see any obvious damage. I first removed and reinstalled the prop. No change. Today I bought a new hub and prop and thought I had it solved, but after about 45 seconds on plane the same things happened. I'm not a mechanic, but it doesn't seem to be electrical / fuel related.

Any thoughts on next steps? I imagine I'll end up dropping it off with somebody, but was hoping to not lose the boat for the next 3 weeks.

In the video below i'm idling along at 4-5mph and try to thottle up.

Thanks in advance for your help.

Wahoo is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 07-04-2019, 07:44 PM   #2
Senior Member
Sailfish
 
Join Date: Aug 2012
Location: Cordova park
Posts: 2,395
Default

Is your oil pump in your big oil tank working? Just shooting in the dark here. A friend had a Yamaha and his oil transfer pump in his big tank quit filling the small tank on his motor. When the small tank got to a certain level the motor would go into a "limp" mode. Hope this helps.
__________________
1996 24 FT Carolina Skiff
115HP C115 Yamaha

"This boat runs on gas, not thank you's"
murfpcola is offline   Reply With Quote Quick reply to this message
Old 07-04-2019, 07:45 PM   #3
Senior Member
Sailfish
 
Join Date: Aug 2012
Location: Cordova park
Posts: 2,395
Default

I have a hard time believing it is a prop issue with two identical brand new props.
__________________
1996 24 FT Carolina Skiff
115HP C115 Yamaha

"This boat runs on gas, not thank you's"
murfpcola is offline   Reply With Quote Quick reply to this message
 
Old 07-04-2019, 07:48 PM   #4
Member
Ruby Red Lip
 
Wahoo's Avatar
 
Join Date: Oct 2007
Posts: 96
Default

Yeah...I'm not suggesting at this point that it's a prop or hub issue. That was just my initial thought and it was the thing on the boat that changed most recently. I think it's ruled out at this point. It's most likely not a problem I'm gonna solve in my driveway, but I thought I'd toss it out there and see if anybody can point me in a good direction.
murfpcola likes this.
Wahoo is offline   Reply With Quote Quick reply to this message
Old 07-04-2019, 07:54 PM   #5
Senior Member
Sailfish
 
Join Date: Aug 2012
Location: Cordova park
Posts: 2,395
Default

On my buddies boat we would top off the engine mounted tank and it ran fine for a while. We would just top it off every little while and it got us home. Good luck and report back once you figure it out.
__________________
1996 24 FT Carolina Skiff
115HP C115 Yamaha

"This boat runs on gas, not thank you's"
murfpcola is offline   Reply With Quote Quick reply to this message
Old 07-05-2019, 10:03 AM   #6
Jaded Old Phart
Blue Marlin
 
kanaka's Avatar
 
Join Date: Oct 2007
Location: C-view
Posts: 5,059
Default

The 90 has a single oil tank. That sound reminds me of what the lower unit does when you shut off ignition while still in gear.
__________________
I can explain it to you but I canít understand it for you.
kanaka is offline   Reply With Quote Quick reply to this message
Old 07-05-2019, 11:11 AM   #7
Member
Ruby Red Lip
 
Wahoo's Avatar
 
Join Date: Oct 2007
Posts: 96
Default

I had to work this morning, but I'm wondering now if this could be related to fuel delivery. I did change the fuel / water separator and, in hindsight, this was the first trip out afterwards. I wonder if it ran good for 30-40 seconds each time because I had just primed it good and fuel wasn't an issue. Could air in the line or loss of prime cause the outboard to act as described?
Wahoo is offline   Reply With Quote Quick reply to this message
Old 07-06-2019, 10:55 AM   #8
Jaded Old Phart
Blue Marlin
 
kanaka's Avatar
 
Join Date: Oct 2007
Location: C-view
Posts: 5,059
Default

As a internet guess, no on the fuel. When that motor, I have one, gets a fuel starvation/lean problem it sneezes then dies.
Yellow River Cat likes this.
__________________
I can explain it to you but I canít understand it for you.
kanaka is offline   Reply With Quote Quick reply to this message
Old 07-06-2019, 07:08 PM   #9
US ARMY 2d ID VETERAN
Sailfish
 
CurDog's Avatar
 
Join Date: Nov 2010
Location: Homeless
Posts: 2,178
Default

^^^I agree ^^^ doesn't sound like a fuel starve issue.
As a guess, kinda sounds like crossed plug wires or premature ignition (spark), maybe a busted magnet?
Just out of curiosity, have you checked the compression? Just to eliminate a bad head gasket.
CurDog is offline   Reply With Quote Quick reply to this message
Old 07-06-2019, 08:07 PM   #10
Senior Member
Sailfish
 
Join Date: Aug 2012
Location: Cordova park
Posts: 2,395
Default

Quote:
Originally Posted by CurDog View Post
^^^I agree ^^^ doesn't sound like a fuel starve issue.
As a guess, kinda sounds like crossed plug wires or premature ignition (spark), maybe a busted magnet?
Just out of curiosity, have you checked the compression? Just to eliminate a bad head gasket.
Good idea. I think most auto parts stores have compression gauges to loan out. I would do that my self before taking it to a shop just to get a baseline.
__________________
1996 24 FT Carolina Skiff
115HP C115 Yamaha

"This boat runs on gas, not thank you's"
murfpcola is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Pensacola Fishing Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
How Did You Find Us?
Tell us how you heard about Pensacola Fishing Forum.

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT -4. The time now is 12:34 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 RC 2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.