Perkins 4.108 Blowing exhaust

[Alex-Lewis]

Just bought an 86 Kaarina Seacat motorsailer. The Perkins 4.108 is blowing a lot of exhaust when cranked, and I can't seem to figure out why. I have included a video for reference.

[azsailor12]

Looks like the injectors are leaking and spraying diesel.

[S/V_Surya]

I agree or head gasket. Try tightening down on injector bolts but be careful the hold downs are easily broken. Low compression is why it will not crank.

[Vipe6]

Were the injectors taken out recently? If so, check that the copper washers under the injectors are inserted correctly.

[captmikem]

It is that number 2 injector. you can see and hear it only blowing on that compression stroke. Would suggest you pull it out, check the injector for cracks, check the copper washer (someone may have even left it out), and look for cracks around the hole the injector goes into. Then put never seize around the base, (NOT on the tip) re-install, (if you can spin it a bit to make sure it seats, then put the nut on it and torque it to 12 ft/lbs.

Michael

[bigman1]

Run a compression test.If low new head gasket with blue hylomar paste both sides. reseat injectors with new washers.

[geedee]

When ever I take my injectors out I always hold the copper rings over the gas flame on the stove... heat them real hot then dunk them into cold water this softens them and they will seal no problem after that.. also use same thing after I undo a flared copper pipe connections and never have leaks . That motor sure sounded like it has a problem for sure.

[northiceman]

My first impression was an injector(s) leaking. Like the other person said-it may be a leak in the engine head. I would start by tightening (no more than 12 ft-lbs) the injector feed lines and the overflow lines (from top of injector). You may want to loosen then back-check if there is one that is crossthreaded and re-tighten. DO NOT bend those copper injector feed lines going to the injectors-because if you do it will be a bitch to get 'em back on again.
Notice the misting - thats diesel coming out under much pressure - whatever you do- do not get your hands near that - a severe blood infection could be the result. There is enough pressure at an injector to inject diesel right thru the skin and into the bloodstream !

[Captain Bob]

It is a difficult problem to analyze from the video but you definitely seem to have a fuel leak on the high pressure side. As others have posted, carefully tighten the injector mounting bolts to compress the copper washer. I always install new ones when servicing the injectors. That engine should start fairly easily on three cylinders providing that there is good compression so I suspect there may be more than one problem. When was the last time that the valves were adjusted (should be every 500 hours)? Is the fuel shut-off cable fully seated on the injection pump? If it isn't, the engine will never start. The injectors should be serviced (replaced or rebuilt) every 1500 - 1800 hours.

4-108s and for that matter all older 4 series Perkins are generally indestructible if kept in a reasonably good service condition which is why they have such a solid reputation. As with all diesels, clean fuel and clean air and a good starting source will make for a a happy and reliable engine.