Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-05-2014, 12:46   #1
Registered User
 
Loki's Avatar

Join Date: Jun 2010
Location: Portland, OR
Boat: Sun 27 - Sun Yacht
Posts: 10
My 8hp Yanmar won't start

I've got a single cylinder, 8hp Yanmar that has started the first time, every time, until now.

When the starter engages, the engine turns, while making a horrible screeching sound, but does not turn over.

Here's what I know and thought of to check so far:
- The starter is new, is fully powered and turns the engine
- the batteries are at full strength
- the air intake is clear
- fuel pump was tested and works properly
- unable to budge the engine with the hand crank - even when standing on the crank handle
- manual compression release lever is frozen closed and broke off when I tried to pry it open

My guess is that I'm looking at a compression issue, but have no idea of where to go from here. Any thoughts or suggestions?
__________________

__________________
Loki is offline   Reply With Quote
Old 25-05-2014, 15:32   #2
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Re: My 8hp Yanmar won't start

Pull the fuel injector and check for water in the cylinder. Sounds like you have a water lock problem. Your post is a little confusing in that you say the starter turns the engine over but you can not manually turn it over. I suspect a typo somewhere.
__________________

__________________
The Blue Dot Campaign. This Changes Everything.
DeepFrz is offline   Reply With Quote
Old 25-05-2014, 15:39   #3
Registered User
 
Loki's Avatar

Join Date: Jun 2010
Location: Portland, OR
Boat: Sun 27 - Sun Yacht
Posts: 10
Re: My 8hp Yanmar won't start

Deepfrz,

Thanks for the suggestion. I'll check for water in the cylinder. Also - it wasn't a typo. I literally cannot budge it by hand, but the starter is able to turn it. I can't be sure, but it doesn't seem like it turns as easily as when it was running properly.

Loki
__________________
Loki is offline   Reply With Quote
Old 25-05-2014, 15:47   #4
Registered User

Join Date: Feb 2011
Location: France, britanny
Boat: Gibsea 302, 9m
Posts: 80
Re: My 8hp Yanmar won't start

I confirm deppfrz's version,
probably a large water input in the cylinder.
check the oil,
risk of damage, you'll have to disassemble the cylinder ...
__________________
bil56 is offline   Reply With Quote
Old 25-05-2014, 15:55   #5
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Re: My 8hp Yanmar won't start

Quote:
When the starter engages, the engine turns, while making a horrible screeching sound, but does not turn over.
Well, I'm sorry to hear this. Sounds like you have a very serious problem. You may be wishing that the starter actually didn't turn the engine over. By the way, how long did the engine sit since the last time it was used?

I take it that you have checked that there is oil in the sump?

Anyway, try squirting some oil into the cylinder when you get the injector out and then turn it over a few times. Possibly the cylinder/rings are rusted.

If everything checks out when you get the injector out then maybe the starter or transmission is the cause of the noise.

A long shot is that something being driven by the belt is causing the problem. That would be alternator or water pump. I suppose it could also be the fresh water pump.
__________________
The Blue Dot Campaign. This Changes Everything.
DeepFrz is offline   Reply With Quote
Old 25-05-2014, 15:59   #6
Registered User
 
Loki's Avatar

Join Date: Jun 2010
Location: Portland, OR
Boat: Sun 27 - Sun Yacht
Posts: 10
Re: My 8hp Yanmar won't start

Bil56,

Thanks for your response. I appreciate the advice.

Loki
__________________
Loki is offline   Reply With Quote
Old 25-05-2014, 16:17   #7
Registered User
 
Loki's Avatar

Join Date: Jun 2010
Location: Portland, OR
Boat: Sun 27 - Sun Yacht
Posts: 10
Re: My 8hp Yanmar won't start

DeepFrz,

Believe me, I wish it was the starter. I did check the oil and did not find any signs of water on the dipstick. I'll try draining the oil and doing a more thorough check. The last time we ran the engine was last September. Rust may be a factor - the starter had frozen and was recently replaced.

I haven't considered the transmission as the potential culprit, and not sure how to check that. I am quickly reaching the limits of my already limited mechanical abilities...

Loki
__________________
Loki is offline   Reply With Quote
Old 27-05-2014, 23:03   #8
Marine Service Provider

Join Date: Jun 2012
Location: Spanish & US Virgin Islands
Boat: Privilege P-45
Posts: 16
Re: My 8hp Yanmar won't start

Get the injector out and turn the engine by hand. It should turn easily, except for what you should feel as flywheel weight. If you get drag or a noise, stop turning it and get experienced or professional help. Same goes for if any fluids shoot out of the injector's hole when turning the engine. Checking condition of the oil "further" at this point is only going to get you further than when you checked the first time if you note for certain it smells like fuel, or the first thing out of the pan is water. Just draining a cup will tell you this. Loosen the lines on the injector and remove them from it... remove the hold-down bolt and clamp and then work the injector out of it's hole in the head. Turn the engine... What happens?
__________________
BOATDOCTOR is offline   Reply With Quote
Old 21-06-2014, 08:58   #9
Registered User
 
Loki's Avatar

Join Date: Jun 2010
Location: Portland, OR
Boat: Sun 27 - Sun Yacht
Posts: 10
Re: My 8hp Yanmar won't start

I wanted to thank everyone for the great tips and advice. The engine is running again. There were actually a couple minor issues that needed to be dealt with. First of all, since the engine had not run for many months, the lack of lubrication caused the piston to stick in the cylinder. Removing the head remedied this issue and the engine was able to be easily turned. The second issue was fuel related. Rebuilding the fuel injector solved this issue and the old Yanmar is again purring like a one-cylinder kitten. Thanks again to those who offered advice and suggestions, and especially to my new friends at H & H Diesel in Tacoma, who managed not only remove the lodged injector (without mangling it), but rebuilding it as well... in a single day.

Stay out of trouble.

Loki
__________________

__________________
Loki is offline   Reply With Quote
Reply

Tags
yanmar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to Turn a Yanmar 8hp Off tsprouster Engines and Propulsion Systems 7 08-03-2014 19:15
Replacing A4 With a Yanmar 8HP Diesel Muscongus Engines and Propulsion Systems 9 17-09-2013 03:46
For Sale: 2012 Tohatsu 9.8HP 4-stroke XL shaft, electric start JimGo Classifieds Archive 1 01-01-2013 19:59
Yanmar 2GM Won't Start After Winter Layup zippy Engines and Propulsion Systems 17 31-07-2011 21:04
Had to abandon ship. Won't start! knottybuoyz Engines and Propulsion Systems 22 25-03-2011 16:06



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:20.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.