Notes on a bargain bought Perkins 4.108 now being brought up to top shape for service

[doog]

So after building from scratch out of the swap meets and DIY work here I am years later aboard my 37 foot roberts design which has proven out well with a reliable Perkins that has served for over 600 hours with great reliability. But the bilge became flooded during a long period of disuse when a limber hole was blocked and I found mud had gathered in the bell housing and messed up the flywheel and ruined the starter. A part fell into the bell housing and I had sudden stoppage and pulled the engine out and removed the flywheel, replaced the starter and cleaned it all up, installed the nice drip pan I wish I had originally fitted and now the engine compartment is crisp and clean and again, the engine runs great.

BUT, this engine has always clattered more than the usual Perkins and I messed with the timing and found it smooths out nicely if its moved toward the retarded end of the slots, but then it smokes. So I found the good compromise. But still, the RATTLE! I was attempting to post a video and ask for diagnostic help. The engine runs great, idles down to 400 rpm and it uses .5 gallons per hour fuel and starts instantly. And I think I know what it is.

You see I put the engine together from a salvage sale where it was totaled for oil pressure loss. But I had it inspected by a machinist and he said there was no damage, So I put it together with fresh bearings and have had months of great use with the engine, But I never set the clearance on the idler gear in the timing case. Im not a bad mechanic but I had no idea what was going on with this cluster of gears that drives the cam and fuel pump and Im pretty certain there is greatly excessive clearance on this gear which Ive never checked or adjusted, making it rattle like it has a loose chain or like a bad alternator bearing about to explode. And when turning the engine over with a wrench it ticks like it has a chain somewhere. But there is no chain in this engine anywhere.

Okay I spent today adjusting valves and changing oil and tomorrow again removing the timing cover and then doing the adjustment on the idler gear to assure the proper clearance between these gears. I wish I could share a clip of the engine running but apparently, I'd need to post it to YouTube and then share the link here. And these forums are so helpful. Thanks everyone for their input and hopefully this is of use to someone with a solid old Perkins. And by the way, a new front seal and with Permatex silicone around the front cover the notorious oil leaks are entirely cured.

Any comments or advice more than welcome.