Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 07-08-2012, 09:51   #1
Registered User
 
Jetexas's Avatar

Join Date: Jul 2009
Location: Houston, TX
Boat: 1982 Oday 34
Posts: 439
Images: 10
Engine dies under load when cold

I have a Kubota Z482. It was brand new when I installed it 2.5 years ago, and it has maybe 40 hours on it at this point.

The fuel goes from the tank to a primer ball to an inline filter to a bowl filter and then to the injection pump.

It's self-priming and always start right away. Purrs like a kitten.

However, unless I let it run for a few minutes, it dies under load. Once it's warm, it does fine.

For example, if I turn it on cold and start backing out of the slip, if it doesn't die when I first hit reverse, it will die when I click back into forward.

Also, if I turn it on cold after sailing and start motoring in, it will run ok for a couple minutes and then start sputtering. If I kick it into neutral, rev it up for a second, then put it back in gear, it's fine and will run normal all the way home.

I just changed the filters, but that didn't seem to change the problem at all. Any other ideas?

Like I said, if I let it warm up a couple minutes it's fine, but I know that's not the way it's actually supposed to work.
__________________

__________________
Jetexas is offline   Reply With Quote
Old 07-08-2012, 10:40   #2
Registered User
 
captainKJ's Avatar

Join Date: Jan 2010
Location: 3rd wave passed the sea wall
Boat: private yacht always moving
Posts: 1,388
Re: Engine dies under load when cold

diesels need to warm up for a couple of minutes. You engine is fine. It also depends on how cold the water is at the intake????? for example in Florida you need less time to warm an engine than in maine.
__________________

__________________
captainKJ is offline   Reply With Quote
Old 07-08-2012, 11:08   #3
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 6,389
Re: Engine dies under load when cold

Have you removed the screen in the fuel pickup line in the tank? Have you checked the fuel filter screen?
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 07-08-2012, 11:13   #4
Registered User
 
Jetexas's Avatar

Join Date: Jul 2009
Location: Houston, TX
Boat: 1982 Oday 34
Posts: 439
Images: 10
Re: Engine dies under load when cold

Quote:
Originally Posted by Stu Jackson View Post
Have you removed the screen in the fuel pickup line in the tank? Have you checked the fuel filter screen?
No. I have not checked any screens. I'll have to look for those.
__________________
Jetexas is offline   Reply With Quote
Old 07-08-2012, 17:10   #5
Registered User

Join Date: Oct 2009
Location: australia
Posts: 467
Re: Engine dies under load when cold

Your problem has all the hallmarks air entering the fuel system some where close by the engine.
__________________
shakey doug is offline   Reply With Quote
Old 07-08-2012, 17:33   #6
Registered User

Join Date: Nov 2010
Posts: 830
Images: 27
Re: Engine dies under load when cold

When you start a diesel car or tractor for example, it is capable of running at close to full RPM, almost immediately. Would suggest that the behaviour or your engine is not normal.
__________________
ausaviator is offline   Reply With Quote
Old 07-08-2012, 17:47   #7
Moderator Emeritus
 
Ex-Calif's Avatar

Cruisers Forum Supporter

Join Date: May 2007
Location: Singapore
Boat: Maxi 77 - Relax Lah!
Posts: 11,514
Images: 4
Re: Engine dies under load when cold

Quote:
Originally Posted by Jetexas View Post
I have a Kubota Z482. It was brand new when I installed it 2.5 years ago, and it has maybe 40 hours on it at this point.

The fuel goes from the tank to a primer ball to an inline filter to a bowl filter and then to the injection pump.
40 hours in 2.5 years is not much running. How much fuel have you put through the tank? I suspect not much.

Current quality of the fuel would be on my list. Clean the fuel system including the tank (stuttering after running a while) and consider replacing the fuel. Also I would definitely check any o-rings in the system for drying out and leaking air in. In fact I would replace them all anyway.

Also after 40 hours since new I would check/adjust the valve clearances and maybe raise the idle RPM a hundred or so.

A longer warm up wouldn't hurt, in gear at 1000 rpm or so while tied at the dock. And finally I would plan to run the engine hard at least once a month. 2500+ rpm motor sail for at least 30-60 minutes.

I don't think there is anything much wrong with your engine that a little PM and hard running won't cure.
__________________
Relax Lah! is For Sale <--- Click
Click--> Custom CF Google Search or CF Rules
You're gonna need a bigger boat... - Martin Brody
Ex-Calif is offline   Reply With Quote
Old 07-08-2012, 17:48   #8
Moderator
 
Boracay's Avatar

Cruisers Forum Supporter

Join Date: Feb 2004
Location: Pelican Bay, Great Sandy National Park
Boat: Steel Roberts Offshore 44
Posts: 5,175
Images: 18
Re: Engine dies under load when cold

My guess would be that the primer bulb is somehow slowing the flow of fuel to the engine.

If it were me I'd try squeezing the bulb just before applying power. May give a clue to the solution.
__________________
Rust never sleeps
Boracay Blog.
Boracay is offline   Reply With Quote
Old 07-08-2012, 18:30   #9
CF Adviser
 
Bash's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
Re: Engine dies under load when cold

Folks, were talking about a 2-banger here. Maybe 13 horses?

An engine like that deserves a good warmup, especially if you're only running it 16 hours per year.

Ex-Calif's advice about fuel quality is worth reading again.
__________________

__________________
cruising is entirely about showing up--in boat shoes.
Bash is offline   Reply With Quote
Reply

Tags
engine

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:17.


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.