Cold Starting Question

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
Wow, Sure is purty.
I would like to ask. have you had any voltage drop from your main buss to the batteries?

The wire I used is for the artic it is blue and flexible at extreme low temperature. It has very small stranded wire and i find less of avoltage drop than standard wire. Depending on how long the run was
Trouble shooting electrical is never easy. I see lots of connections that I would check first. before I worried about anything else.
The way you have it set up should make checking things out a snap.
 
Why, because I used TINNED wire, of course! :rofl::lol::popcorn:
(Sorry, I figured you were in on at least one of the threads I had going about it.)

I probably was, but with all that I put into my brain, I have to delete things from time to time so I probably deleted your rewiring post.

As for trying to help, my entire career involved finding out why things didn't work and making them so they did. I learned to troubleshoot and I learned to think about what could cause them not to work before jumping in and making assumptions.
 
A Diesel engine ignites the fuel on the compression stroke by the heat in the compressed air.

The cold (50 isn't cold) block will absorb more of the heat of compression , a cold battery has far less power than a warm one so the cranking speed may be lower.

Additionally the summer oil is thick , and the unused engine has little oil left on surfaces to assist crank speeds.

For many engines there IS a minimum crank speed to start.

Sure a block heater is a fantastic cure, if operating, but there are other techniques.

First in the cold ONLY (cold is below 32F on most diesels) a single shot of ether will do the task, as the ether firing will help heat the cylinder to fire diesel.

Ether as an alternate fuel in the cold poses no danger on a non auto sourced engine.

Not for a VW , or Yannmar Toyota, BMW marinization.

The basic start technique is fior those folks that still have those 8D batteries specified by the engine converter.

Crank for 15 to 30 seconds (look in Da Book) , stop and allow the starter to cool about 30 to 60 seconds, do it again , usually 3rd time there will be the start as the cylinder will be warmed from the compression strokes and some oil put out on the cylinders .

The start will be with MASSIVE amounts of smoke , as the engine will be injecting fuel during the crank periods.

You could say its great for killing mosquitos , but there seldom a hassle at 32F.

Below 0F usually only the alternate fuel ETHER , will get the start.

Those old heavy 8D were specified for a reason , not needed in South Fl, but a great help where 32F or below is not uncommon.
 
Last edited:
The use of ether is what blew the rings out of my genset and cost me a $1500 rebuild. So I am understandably timid over the use of ether. :ermm:

Sounds to me like I may have a few other things to check. Although, most I have checked already. ;)
 
The use of ether is what blew the rings out of my genset and cost me a $1500 rebuild. So I am understandably timid over the use of ether. :ermm:

As noted Ether is for bigger diesels than in most gen sets.

Usually ether causes destruction as folks use it in warm times to attempt to get an engine started and suck fuel from the tank, and fill the injection pump, rather than bleeding the fuel system properly.

Were you using a SHOT of ether below freezing , when the rings cracked?
 
The use of ether is what blew the rings out of my genset and cost me a $1500 rebuild. So I am understandably timid over the use of ether. :ermm:

Sounds to me like I may have a few other things to check. Although, most I have checked already. ;)

You shouldn't have to use ether to start your engine. I'm assuming that at some point in the past it would start fine when cold so something has changed. Find what has change, correct it, and you're back in business.
 
We have 4D batteries starting and house, Our lehman 120 starts right up at 50 degrees same as 75.

JohnP
 
It wasn't cold. The temps were in the 50's by noon. The engine room was in the 50's at least if not warmer all night. It may have gotten to 29* for two minutes at night but the water temp is still high at out marina.

NS hit on it. What oil weight is in the engine? Your battery may be a little light for 30 wt oil in 50* temps. 4 D is probably enough.
 
My Perk has always been hard to start, warm or cold. Always takes 10 to 15 seconds to get her to fire. Low compression perhaps?
 
Run 15W40 oil and an H7 , 790CCA battery and no problem starting down into the 40 degree range (outside air temps in the 30s).
 
My Perk has always been hard to start, warm or cold. Always takes 10 to 15 seconds to get her to fire. Low compression perhaps?

Turning over and starting are two different things. In this case it would not turn over fast enough. So it can't start. If it turns at 500 rpm and doesn't start there is a different problem. But she has to spool up to start.
 
The use of ether is what blew the rings out of my genset and cost me a $1500 rebuild. So I am understandably timid over the use of ether. :ermm:

Sounds to me like I may have a few other things to check. Although, most I have checked already. ;)


Use WD 40 instead.
 
Both the main 671 and the Perkins gen start with in two revolutions/seconds. If not something is wrong. Each April I have my diesel mechanic to start both engine cool, let him listen/look and adjust/tweak the engines. Most of the time its less than 30 minutes while he check/looks for leaks and check things. If you are having trouble starting/turning over the engine, it might be as simple as changing the wing nuts to regular hex nuts with locks rings and cleaning the terminals and cables.

It could be argued that every start is a cold start to some degree? A cold start for a boat engine should be the same as other engine. The concern is viscosity and congealing of the oil and/or diesel. 55 F degree is not a hard cold start as the oil and diesel should still have good viscosity at that temp there should be little/not different in starting if it has not been a long time since it was last started.

Usually part of the discussion is how often to cold star and how long to run? That is depends more weather the engine is a 2 or 4 stroke, more so if a 2 stroke. One of more cylinders are left open, which could cause pitting/corrosion if cylinder walls are not protected. The range of time between cold starts is debatable. However, in the Seattle/Puget Sound area, ambient water temp is 50 F degree, I use 60 days before the metal surfaces should be re coated and the length of time about 2 minutes to allow oil to flow through the engine, move fluid, and parts.
 
It could be argued that every start is a cold start to some degree? A cold start for a boat engine should be the same as other engine. The concern is viscosity and congealing of the oil and/or diesel.

True statement. In fact temps in the 80 or 90 degree range are a cold start to some degree as far as the engine internal parts are concerned. A warm start is when the engine is up to temp and has been running for a while. It's all in how you look at things.
 
On cold-day starts, my JD starts immediately but then stalls after several seconds even if throttle set well above idle speed. Subsequent attempt takes five seconds of engine turning for engine to catch and then run without stalling. If engine is warm, it will start up immediately and not stall.
 
So after your initial 'slow turning over' to start episode that morning, did you try to restart after the engine warmed up?
 
So after your initial 'slow turning over' to start episode that morning, did you try to restart after the engine warmed up?

Actually, no. I thought about it, but just didn't. Sorry. I will try it all again this weekend and check all the connections and stuff and junk and things. TBH, it might, indeed, be the ground to the block. I don't recall if I re fitted that wire with a new connector when I did the one on the starter lug.

Tom-
 
Multi-vis oil is not needed to start trawler engines that are 50 degrees.

If an engine is hard starting at 50 degrees it has a problem.

If you have a keel cooler and your engine is -5 degrees you may want to consider multi-vis oil.

Mark wrote, "On cold-day starts, my JD starts immediately but then stalls after several seconds even if throttle set well above idle speed. Subsequent attempt takes five seconds of engine turning for engine to catch and then run without stalling. If engine is warm, it will start up immediately and not stall."
By "stalls" do you mean quit? You must have air leakage or >>> ? I'd tell that to your mechanic.
 
Last edited:
The use of ether is what blew the rings out of my genset and cost me a $1500 rebuild.
Ether, or something very similar, sells here in an aerosol can under the brand "Start You Bastard". Used for recalcitrant lawn mowers. trimmers etc,and the odd outboard.
 
Ether, or something very similar, sells here in an aerosol can under the brand "Start You Bastard". Used for recalcitrant lawn mowers. trimmers etc,and the odd outboard.

Thanks for that Bruce. I'll now wear out my keyboard attempting to locate an importer. I'll display it in a prominent location on my work bench.
 
Mark wrote, "On cold-day starts, my JD starts immediately but then stalls after several seconds even if throttle set well above idle speed. Subsequent attempt takes five seconds of engine turning for engine to catch and then run without stalling. If engine is warm, it will start up immediately and not stall."
By "stalls" do you mean quit? You must have air leakage or >>> ? I'd tell that to your mechanic.

Yes.

I'll mention it to the mechanic when I take the engine in for a scheduled valve adjustment later this year. :angel: Have 200 hours on the JD now.

Meanwhile, I'll try priming the engine first with the fuel polishing pump (various fuel lines/valves permit this), but this problem only occurs during chilly weather.
 
Last edited:
I use 4D's as starting batteries... 1000 CCA. Most type 31's are 700 to 750 CCA. Depending on how often the batteries are charged...if let to sit for a while without a trickle charge being applied...they will lose a little ooomph over time....and if the temperature drops the battery will lose some oomph as well.

Is your charger set to compensate for the ambient temperature?
 
On cold-day starts, my JD starts immediately but then stalls after several seconds even if throttle set well above idle speed. Subsequent attempt takes five seconds of engine turning for engine to catch and then run without stalling. If engine is warm, it will start up immediately and not stall.

I wonder if you have a low oil pressure cut out switch kicking in after a several second delay timer. Possible but not probable.
 
JAT,

I think my "Optimax" starting batt produces 1000 CCA. It's the size of a typical car battery.
 
How many have started a cold engine at 20F or below?

A super modern engine with electric injection will go, our Series 50 DD has no problem, with BIG batteries to get crank speed.

But for most existing boat engines at 20F its a shot of alternate fuel , ETHER or oars.

Freezing and below becomes a challenge for even an engine that is not worn out.
 
JAT,

I think my "Optimax" starting batt produces 1000 CCA. It's the size of a typical car battery.

If its a "bluetop"....then it has 800 CCA, and 1000 MCA. And it should start the motor fine.... My experience with diesels is that when it gets chilly....they tend to be a little finicky at times...

But.... two other thoughts come to mind... Have you had the battery load tested to see how good it still is? And, is it possible that your starters is getting a little sluggish on its own?

Does your boat have a battery combiner switch? Does it start faster when put to use?
 
JAT,
Yes it's a blue top. I was just going by my recollection. I wanted a boat that would start right up when we moved to Alaska. Had AGMs on the previous boat. Saw the Optimax and went for it.

I have no problem whatsoever w the starting performance of Willy.
 
Does your boat have a battery combiner switch? Does it start faster when put to use?

Going to try that this weekend.
 
Back
Top Bottom