OSS AD3 rebuild...

[WRM]

It had (I caused) a "catastrophic failure" last year, but I can fix it? This is the first time I've set my toolbox next to me since last season and it feels good!...

One of the clutch bearings had failed, crank bearings "feel OK" but will be replaced (total rebuild).

Was going to keep flywheel & housing, but don't like the wear on the pinion, and it's a full rebuild. Hope to have it fired up this weekend?...

We shall see.

 

[WRM]

Took about 1.5 hours last night (no pics), I was ready for some new clutch, shoes anyway (and new clutch bell bearing)?...

Used Red's bearing kit. The bearing failure bag in the above photo (and LR in this) was actually from the timing end on my Red's Gen 3 2250kva motor...

Going to get a run in with the new engine tomorrow, then swap it out/spare and get this one fired up!

Cheers,

 

[ltdpos]

so the connecting rod came apart? it didn’t score or damage the block and crank?

 

[WRM]

Broke the rod and the crank pin stopped in the middle of the rod the next rotation. Didn't note any significant damage to the block or crank, but the piston skirt was damaged by Con Rod, so new rod/piston/cylinder (and bearings, since I had it apart). Re-used block, crank, flywheel, Carb, and head button/fins, and everything went together nicely, no contact/rubbing. I'm heading out to meet my buddy at the track but only taking EB. NB also needs center diff attention, so good thing there is still a month until the first race.

I'll keep you posted.

Thanks,

 

[WRM]

Another "Success" story....

Took the new (spare) engine to the track on Friday and ran a couple tanks through it on asphalt/parking lot, and it needed 3-4 hours lean on the main from the bench tune. Swapped the rebuilt and bench ran it today for over an hour (still idling), very pleased. Did 10 min pre-heat on head w/pro-tech heater (put an XT-60 power tap into my starter box), used the new 6-24V igniter, and it fired right up!

Both took a couple hours lean between first start/heat cycle and second start, and this one is ready for the track (after I fix C Diff).
Yea!

 

[WRM]

Removed and inspected C-Diff last night and found no issues. I don't think I had enough backlash between clutch/pinion and C-Diff ring gear when I bolted the engine in and honestly didn't check it (lesson learned). Good thing I didn't run it too long (or "drive it") - now have enough and should be good! EB and NB are both ready for the season opener on April 4....

Meanwhile, I got a call/message from Rovan today about Sunday night's order - they can't ship my (green) 305A to a PO Box, so I E-mailed my shipping address. Hoping to have that soon (next week?), already have 2-cycle oil and spare plugs. Also have that "winter project" MT 48 kit in the box, waiting for me to start on it?...