Perkins 4-108 questions

[fireman182]

Hello

I've attached 2 pics of my perkins 4-108

I'm trying to install a thermos start but the spot where they traditionally go doesnt look like its designed for a thermos start.

I reefed on what looks like a removal able plug for the heater but It doesn't move at all.

Shes getting hard to start during haul out and launch without any heat source.

Any ideas?

The second question. There is a stainless steel rod about the thickness of a paper clip that moves in and out. What is that?

Would there be a decompression lever anywhere on this old man perkins?

Thanks!

[rbk]

Originally Posted by fireman182

Hello

I've attached 2 pics of my perkins 4-108

I'm trying to install a thermos start but the spot where they traditionally go doesnt look like its designed for a thermos start.

I reefed on what looks like a removal able plug for the heater but It doesn't move at all.

Shes getting hard to start during haul out and launch without any heat source.

Any ideas?

The second question. There is a stainless steel rod about the thickness of a paper clip that moves in and out. What is that?

Would there be a decompression lever anywhere on this old man perkins?

Thanks!

In your second picture where the black plastic conduit crosses the engine appears to be the location of where the thermostat is installed with the forward header tank install. Take a picture of the whole engine from the front (if you can).

[stormalong]

On your second picture to the left and above the arrow is the location of the thermostat. Two bolts hold down the cap that covers the thermostat.

I don't know what the stainless rod the thickness of a paper clip is. Can you provide a closeup?

[fireman182]

Originally Posted by rbk

In your second picture where the black plastic conduit crosses the engine appears to be the location of where the thermostat is installed with the forward header tank install. Take a picture of the whole engine from the front (if you can).

I think you're right that's the termostat

I'm trying to install a thermo start. Its a flame heater to assist with warming the air going into the engine. This was before glow plugs.

Like the one in this video

https://youtu.be/NeDvCVS38hk

[fireman182]

Originally Posted by stormalong

On your second picture to the left and above the arrow is the location of the thermostat. Two bolts hold down the cap that covers the thermostat.

I don't know what the stainless rod the thickness of a paper clip is. Can you provide a closeup?

Here is a zoom of the same pic. Ill try to get another pic later.

It moves in and out. Haven't touched it while the engine was running

[rbk]

Originally Posted by fireman182

I think you're right that's the termostat

I'm trying to install a thermo start. Its a flame heater to assist with warming the air going into the engine. This was before glow plugs.

Like the one in this video

https://youtu.be/NeDvCVS38hk

Ah, thought you’re auto correct was messing with you. From what I gather that would be the spot for thermostart. No idea that the rod is. No decomp lever on the 4108

[stormalong]

Originally Posted by fireman182

I think you're right that's the termostat

I'm trying to install a thermo start. Its a flame heater to assist with warming the air going into the engine. This was before glow plugs.

Like the one in this video

https://youtu.be/NeDvCVS38hk

What you are calling a thermo start in called a cold starting aid in Perkins terminology. It is located in the throat under the air intake screen. It has a fuel line attached to it and a place to attach a wire for the heating element of the starting aid. It drips hot fuel into the air intake when power is applied.

The wire is probably the end of the cable attached to the throttle, it just was not cut short. Perhaps the original installer left some extra cable for future adjustment or perhaps he was just lazy.

[fireman182]

Originally Posted by stormalong

What you are calling a thermo start in called a cold starting aid in Perkins terminology. It is located in the throat under the air intake screen. It has a fuel line attached to it and a place to attach a wire for the heating element of the starting aid. It drips hot fuel into the air intake when power is applied.

The wire is probably the end of the cable attached to the throttle, it just was not cut short. Perhaps the original installer left some extra cable for future adjustment or perhaps he was just lazy.

Ya I think that's probably what the cable is. Lazy is probably right as well haha

The cold starting aid should be in location of the pic I circled. Whatever is in its place does not move. I'm not sure what that is or why it's there.

I have all the parts to complete the installation of the flame start but it doesn't seem to fit where it should.

[Argyle38]

The circle in the first picture is the correct location for the thermostart. It looks like this:
https://www.parts4engines.com/perkin...g-thermostart/


You'll need an adapter, that's why the threads don't look right:

https://www.parts4engines.com/perkin...wplug-adapter/


As stormalong said, you also need to connect it to power (through a momentary button or position on a key switch) and a fuel line to the correct output on the fuel filter housing. You will also need a 2nd wire to the engine block for grounding. The adapter is nylon so the device doesn't ground directly to the block. You need a large ring terminal, wire, then another ring terminal to a nearby bolt.



The ss wire rod could be attached to the throttle or could also be attached to the fuel shut-off lever.

[Lepke]

If you're having trouble getting the plug out, rent an electric impact wrench. Impacting works when wrenching just breaks something.

[coopec43]

Have you had a look at these links?

https://www.google.com.au/search?sou....0.3c_hJBJ5uAQ

You can try these links also. If you see an image that interests you, click on it, and that will take you to the article it came from. Then click on "visit"

https://www.google.com.au/search?q=4...w=1163&bih=528


Clive

[WanderingStar39]

My boat, built in Florida, has no preheaters on the 4-107. In cold weather I just use both batteries to start, it generally starts on the second try.

[fireman182]

Wow thanks for all the replies!

I got that blue plug off. It was a bear to get off. Stuck on since 1974.

Its 1 1/2 in size if anyone else needs to remove it.

[fireman182]

Originally Posted by Argyle38

The circle in the first picture is the correct location for the thermostart. It looks like this:
https://www.parts4engines.com/perkin...g-thermostart/


You'll need an adapter, that's why the threads don't look right:

https://www.parts4engines.com/perkin...wplug-adapter/


As stormalong said, you also need to connect it to power (through a momentary button or position on a key switch) and a fuel line to the correct output on the fuel filter housing. You will also need a 2nd wire to the engine block for grounding. The adapter is nylon so the device doesn't ground directly to the block. You need a large ring terminal, wire, then another ring terminal to a nearby bolt.



The ss wire rod could be attached to the throttle or could also be attached to the fuel shut-off lever.

Thanks for this information! Very helpful. I have the plug and adapter from the previous owner who started the install but never completed it.

Do you happen to know the fuel line output size? or what part that is needed for a fuel line connection?

What size wire do you think is required?

It would also need a fuse/breaker?

[fireman182]

Originally Posted by WanderingStar39

My boat, built in Florida, has no preheaters on the 4-107. In cold weather I just use both batteries to start, it generally starts on the second try.

Trade ya, I'm in Ontario Canada where the boating season is very short