How Long Before Your Perkins 4.108 Starts?

[Hampus]

Hey!

For how long do you with Perkins 4.108 have to crank it before it starts? I need around 10-20 seconds of cranking, while the Yanmar in the old boat fired up emediately. On th plate with starting instructions for the Perkins it sais something like: preheat, start. If the engine hasn't started within 20 seconds, preheat again. Preheat works but 20 seconds seems like a long time. Engine runs fine otherwise.

/Hampus

[CSY Man]

My 4-108 does not have a pre-heat option, but starts right up.

If you have to crank for 20 seconds, somethings is seriously wrong.

Do you give it a little "gas" when cranking? (Crack the throttle)

Check the compression and or overhaul the injectors.

[svHyLyte]

I always count Hyppopatamus's ("seconds") when I start our engine and rarely ever get to "Three Hyppopatamus". Our engine is a 1986 era, English issue, 4-108 with 3300+ hours.

FWIW...

[S/V New Sensation]

My 1983 4-108 is of two minds when it's warm here in the NW it fires up practically before it's completed a revolution. When it's cold (and the engine hasn't been run recently) it is dificult to start and a combination of long cranking and preheat is necessary to start. Depending on temperature your engine's behavior seems normal to me.

[S/V_Surya]

MY engine used to fire right up until I changed the fuel filter, now after sitting for a week I have to crank about 10 seconds. If I shut it down it starts right up. So I am sure I am getting a small amount of air into fuel line.

[forsailbyowner]

Mine started almost immediatly with the original direct drive starter. After changing to gear reduction it takes longer. Never 20 seconds though more like 5 or 6 cold.

[Cheechako]

mine always started up immediately. So much so it was hard to even nudge the starter for rotation if i needed to without it starting... Never used the heaters, actually, cant remember if it had them (Pac NW)

[fred]

Slow start when engine is hot or cold? Or both??
Does it smoke excessively after start up??

How may hours on the injectors since they were serviced and calibrated??

Is your filter new?
Fuel fresh and treated?
Seals new on the fuel system?

Sounds like air, if it runs well after start up.

20 sec. cranks will burn out the starter motor quickly...short bursts only.

I'd fix that soon.

fred

[Cheechako]

how many hours? Low compression? (rings or bad valves)

[Hampus]

2800 hours. No smoke after startup, it runs great actually. Starts imediately when warm. If I start it with full throttle (and pull back the moment it fires up) I only count to 4 hippopotamusses before it starts. Takes a lot longer if I try to start it with no throttle.

Starting instructions for cold weather in the manual sais that if it hasn't started within 20 seconds, you should try to heat some more and start again, so I guess it acts normal after all.

[Sandero]

I have a 24 yr old Volvo MD17D - starts instantly in the summer and in 2 seconds in the spring for the first time. 4200 hrs

[onestepcsy37]

of pushing the start button. i give it about half throttle before starting. as soon as it kicks i pull the throttle back to about 900 rpm and then after ten seconds i pull back to idle.

i think the instruction book tells you to use half throttle when starting.

i'm in central florida.....

[fred]

The manual says 20 seconds, but I wouldn't crank it for a straight 20 secs.
Short bursts or you will shorten the life of the starter.

I asked the local diesel "expert"...
we were tipping a few at "The Dock House"....

He's been working on fishing boat engines, here in Beaufort, forever and is old as dirt.
He said 20 seconds is way to long if the engine is to specs.
He has 1000 hp diesels with over 5000 hours, start up in 5 secs. cold!!

He said the main reason diesels will not start cold is air in the system.

When the fuel is hot from the engine running it has lots of positive pressure pushing out of various connections.
As the engine cools the fuel 'shrinks" causing negative pressure which sucks in air at every connection with a bad/old seal.

A couple things he would look for are:

~ Injectors...what does the manual say for hours until maintenance/rebuild
~ Connections - check for tightness.... every one from the injector back to the primary filter replace or install new o-rings where necessary.
~Most likely it's the feed to the pumps both high and low pressure....that will effect all cylinders

I asked him what could be done if those things didn't work.....

Smart ass said:

"Live with it... buy a back-up starter... "

A man of few words....I bought him another beer.....

fred

[Hampus]

Thanks Fred!

[GordMay]

Originally Posted by fred

The manual says 20 seconds, but I wouldn't crank it for a straight 20 secs.
Short bursts or you will shorten the life of the starter...
... He (local diesel expert) has 1000 hp diesels with over 5000 hours, start up in 5 secs. cold!!

5 - 15 seconds maximum.
5 - 10 seconds usual.