I posted here about a couple problems I've had during reassembly of this motor (my first rebuild). Thanks for the imput everyone. I knew other issues would arise before it was complete, and of course they have. The first one was a leaking fuel pump. It didn't leak before, so I couldn't understand why it would after a careful rebuild. I took it apart and reassembled it several times, and I could see it was the O ring. So ordered new O rings and cap, and instant fix. Somewhere along the line a different cap was installed, because the new one was noticeably thicker.
So did the tank test yesterday and it started on the third pull. Idled pretty well too. OEM called for break-in to run first 20 minutes at 1500 RPM in gear. Anyway it died after 10 min and it was late so I went at it again this morning in much better light. It didn't want to start, but after playing around with it, I got it running. The motor sounded very healthy, compared to before the rebuild.
Anyway, I noticed some water leaking out from behind the thermostat, looked like it was coming from the head gasket. So I doubled the RPM and water was squirting out from the HG a couple of inches. I double checked the torque, but that was OK, so I pulled the head off and noticed a depression about 3/8" wide X almost the thickness of the powerhead case right above the top cylinder. This is clearly the problem. I prepped the damaged spot and filled it in with some JB weld.
I also noticed some type of tan colored "patching" on the PH just forward of the damage. I thought the machine shop put it on because I got it back sandblasted and it was painted when I sent it to them. I called them and they said they don't do that. They "repair" engine parts. So maybe it was under the paint and hidden, but it looks like it was clamped wrong. Either way, that water leak was never there before, and I know I didn't damage it when I re-installed the head.
I'm just wondering if that JB weld is a legitimate repair choice for a machined surface like that after it is smoothed flush? The head will be bolted over the repair, so I would like to think it will be OK? Machine shop said the pressure in the water jacket is about 16 PSI...I have no idea. The beat goes on...
So did the tank test yesterday and it started on the third pull. Idled pretty well too. OEM called for break-in to run first 20 minutes at 1500 RPM in gear. Anyway it died after 10 min and it was late so I went at it again this morning in much better light. It didn't want to start, but after playing around with it, I got it running. The motor sounded very healthy, compared to before the rebuild.
Anyway, I noticed some water leaking out from behind the thermostat, looked like it was coming from the head gasket. So I doubled the RPM and water was squirting out from the HG a couple of inches. I double checked the torque, but that was OK, so I pulled the head off and noticed a depression about 3/8" wide X almost the thickness of the powerhead case right above the top cylinder. This is clearly the problem. I prepped the damaged spot and filled it in with some JB weld.
I also noticed some type of tan colored "patching" on the PH just forward of the damage. I thought the machine shop put it on because I got it back sandblasted and it was painted when I sent it to them. I called them and they said they don't do that. They "repair" engine parts. So maybe it was under the paint and hidden, but it looks like it was clamped wrong. Either way, that water leak was never there before, and I know I didn't damage it when I re-installed the head.
I'm just wondering if that JB weld is a legitimate repair choice for a machined surface like that after it is smoothed flush? The head will be bolted over the repair, so I would like to think it will be OK? Machine shop said the pressure in the water jacket is about 16 PSI...I have no idea. The beat goes on...