Recíd break-in tips for rebuilt Ď62 VBB
Post Reply    Forum -> Not-So-Modern
Author Message
Hooked
1977 Super 150 (PT Danmotor), '64 VBB, a few old motorcycle projects
Joined: 01 Apr 2017
Posts: 182
Location: Western Mass., USA
Thu Aug 15, 2019 12:58 pm quote
Hi all. Iím putting some easy miles on a VBB2 150cc engine that I rebuilt a couple of weeks ago and then reinstalled into this old rat bike. Itís running nicely once again. Iíve put around 50 miles on the new motor, all told, so far.

What break-in procedures do you like to follow with a newly built engine? How long to take it easy for in order to allow the new parts and old gears and cases, etc etc to meld together nicely?

Just for reference, I installed all new bearings, oil seals, gaskets, o-rings, and I rebuilt the clutch, replaced the shifting cross, kickstart gear, and replaced the gear shift cables. Wonder if I forgot anything...

Speedo/odo works fine ó it has over 12k miles ( the frame is actually newer... a 1964). I believe itís a former Shriners bike.

I put in a spiffed up old dellíorto 20/17 carburetor, and slapped on a new ďstockĒ Sito exhaust. It all feels about right. Some day Iíll restore the rest of it, and replace the wiring.

Thanks for your input. Cheers

21BF64D2-E657-40F8-BA3B-96758F4FFF7B.jpeg

Hooked
1977 Super 150 (PT Danmotor), '64 VBB, a few old motorcycle projects
Joined: 01 Apr 2017
Posts: 182
Location: Western Mass., USA
Thu Aug 15, 2019 1:01 pm quote
Old barn for old bikes

8819B652-959A-4BA1-A0A2-0966F17D283C.jpeg

Hooked
1977 Super 150 (PT Danmotor), '64 VBB, a few old motorcycle projects
Joined: 01 Apr 2017
Posts: 182
Location: Western Mass., USA
Thu Aug 15, 2019 1:02 pm quote
Mph speedo

BAA89F29-E474-4812-A17E-06F1FC35B467.jpeg

Style Maven
74 50s x3 78 P200 84 Cosa PK50XL2 58 AllState 68 Sprint 80 50special '66(?) Super125
Joined: 22 Nov 2010
Posts: 7851
Location: seattle/athens
Thu Aug 15, 2019 1:38 pm quote
Looks good & sounds like you are on track. You didn't mention the top end. Did you get new rings & hone the cylinder? Did you do a compression test?
Hooked
1952 Allstate 1955 Allstate 1958 lambretta 1965 Allstate 1968 sprint
Joined: 20 Jul 2017
Posts: 476
Location: Central california
Thu Aug 15, 2019 7:43 pm quote
Break in
Iím with voodoo. What about the crank/ rod, and top end. If you did not replace any of those parts, there really is not a break in period. Ride it like you stole it....as they say.
Hooked
1977 Super 150 (PT Danmotor), '64 VBB, a few old motorcycle projects
Joined: 01 Apr 2017
Posts: 182
Location: Western Mass., USA
Fri Aug 16, 2019 3:30 am quote
Ah, yes sorry... forgot to mention top end and also the crank. So, I replaced the piston rings with new - standard size. The cylinder actually looked good to me. I reused the stock deflector piston and reinstalled it correctly.

I had the crank checked for true at a local shop (I donít have a dial gauge and stand etc yet), and it was within spec.

I do have a compression gauge around here somewhere. I didnít check yet but will this weekend.

In light of the new rings, what would be your break-in approach if any? Thanks!
Hooked
59" Allstate
Joined: 03 Aug 2018
Posts: 191
Location: TC Florida
Fri Aug 16, 2019 4:05 am quote
If it was mine I would just run it, No prolonged idling, No prolonged WOT runs, No lugging it in the wrong gear either. Roll on the throttle hard at times and let the motor wind a bit, it will expand the rings. You should be fine, you are running the old piston and same bore so you are safe on clearance.

Ill be interested in what the other have to say.

Rick
Hooked
1977 Super 150 (PT Danmotor), '64 VBB, a few old motorcycle projects
Joined: 01 Apr 2017
Posts: 182
Location: Western Mass., USA
Fri Aug 16, 2019 5:52 am quote
Hey all. Appreciate the input!
Fwiw, just so I have an approximate baseline, I tested compression just now (I only have limited experience with doing this on a few motorcycles...) and got about 100 with a morning-time cold motor.

This tester is a multi-vehicle type, and because of the short plugs on Vespas, I didn't use any attachment -- just the short threads on the compressor's hose itself. Also, I'm not sure whether just moderately hand-tightening the hose onto the cylinder head will suffice for a totally accurate reading.

But as other pointed out, this isn't a tuned motor and I have a simple stock setup with no change to the cylinder bore (although rings are new). So I'm not going to over-analyze it! It runs very nice and steady after the rebuild.

One day, when life and time allow it, and I restore the bike properly I'd like to pop on a new top-end 177 kit and new exhaust, in search of more power.

IMG_9236.JPG

Hooked
1952 Allstate 1955 Allstate 1958 lambretta 1965 Allstate 1968 sprint
Joined: 20 Jul 2017
Posts: 476
Location: Central california
Fri Aug 16, 2019 7:09 am quote
Break in
Iím with Amy...just ride it. Have a great time.
Your Rally Here   vespa scooterwest scooter west Motorsport Scooters   Cool Ass scooter seat cover
Post Reply    Forum -> Not-So-Modern
[ Time: 0.1527s ][ Queries: 28 (0.0469s) ][ Debug on ]