I miss my Perkins

I miss how fast my old Perkins 6.354 na would start compared to the 120 Lehman we have now. I’m getting used to it but the Perkins would start in less than 3 seconds no matter how long between starts, even in cold weather.

Maybe the fuel pump is getting weak or are the Lehman’s in general slower to start than a Perkins? I’m having to open the throttle at least halfway to start.

The Perkins always started at idle speed. Any thoughts?

Repower.

Ted

O C Diver said:

Repower.

Ted

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That’s a good one Ted. I remembered you saying more than once at the dinner we had together a few years back “I just write a check”
When are you coming through this way again?

My Lehman starts in 3 seconds or so. 3700 hrs. From reading, half do, half are cranky for some reason. Some get fixed. Normally don't hear about the rest after the first blizzard of posts....at least I miss them.

My Lehman also starts quickly in a couple of seconds. At idle speed.

So did the Perkins T6.354 I had in the old Mainship.

In addition to the two I owned for decades, I have extensively run and maintained the Lehman 120s in a few other boats, and my brother owns two of them now. I have never seen one slower than just a few revolutions to start unless the poor thing was just out of fuel due to an air ingestion issue which was always easy to resolve. Another thing you might want to look into was when was the last time the valve lash was adjusted and the injectors serviced. I used to take all 12 of my injectors in for service every couple of thousand hours or so.

Thanks for the input. This is a 2704E from the late sixties with 5000 hrs. I’ve been told it’s 108 hp and not 120. Is that correct? It looks like it has the same bore and stroke as the 90 hp 4 cylinder but with 2 more cylinders.

Yeah my 120's start up immediately every time. I have heard that they can be stubborn in colder climates, but we don't have that issue here in San Diego.

mine starts quick at idle . but it's a mid 80's 135 . I try to run it every 6 weeks or so. and usually keep my engine room 45deg or more. it smokes less than 50 deg.

Slow start is most likely injectors or low compression. If the injector pump wasn't putting out high pressure the engine wouldn't start. When the compression gets low, the engine cranks longer to warm the cylinders. When the piston compresses the cylinder air it need to reach 500°F or more. Each compression stroke warms the cylinder a little more until it is starting the compression stroke at a warm enough temp to reach the ignition temp of diesel.
A way to check is use a hair dryer to blow hot air into the intake while cranking. If the engine starts quicker with the hot air, it's compression. If not, injectors need cleaning/rebuild or new tips. If it's compression, add a block or pan heater.

I don't start my Lehman 135 unless I need it or it has been a couple months. It has 6000 hrs and is perfect.

After sitting I crank it while cutting the fuel vs stop button until I get oil prs.

I keep a heater in the engine room and it stays between 75 and 85.

During regular use you just touch the key.