Doing a little surgery:

[speeder]

Originally Posted by Baz

Like the kickstand used to hold her up with wheels removed.....very handy!

That is the center stand but yes, it balances out nicely.

[Skip Newsom]

Great Project Denis!

My Son dragged a '71 Bonneville home from Oregon a couple years ago.
It was missing a few things... center stand, motor, you know the usual.

We found and stuffed a 750 motor in first... it seized up for unknown reasons (yes, it had plenty of oil in it) and happenstance led me to a recently rebuilt 650 motor that was too cheap to pass up.
We stuffed it in, tuned and it's cranking along well (for a Brit bike) over 500 miles now.

She's overdue for matching paint instead of the current conglomeration of parts.
I'm very impressed with it's torque... there is some vibration, that's how you know it's running.
I'm in a habit of riding back the same route I used to look for parts that likely fell off...
Good times!
First motor stuff event


That right there Son is a kick starter!


Going in


Progress


Marking it's spot despite the Porsche doing so long before


Alive and motivating it's self about

[speeder]

Nice going! I'm getting a quick education on these motors, I'll post more soon.

[Bob Kontak]

Originally Posted by speeder

Yes, they go up and down together and fire 180 deg. apart.

Not a bike guy but I find this stuff fascinating.

So, I'm thinking this 90's Honda 750 Magna I owned for a couple of years (not much riding) would surely have a swanky staggering of the crankshaft journals with the dual OH cams, etc.

Nope.

Here's a '68 650 Bonneville crank:



Honda 750 Magna crank:



My hands did go numb riding that Honda. I don't know how big the pistons are in the Honda but I gotta think it has to do with these two bikes being a "stroker" vs a "spinner", just talking. I heard that term once. :-)

Nice looking bike.

[Speed metal]

I miss my old Tiger!
Love the Triumphs. I still recall it vibrating my fillings out haha!
Cool bike you have there!

[Rot 911]

Just went through a similar project on my 71 Tiger!

[Baz]

I usually browse the motorcycle section of our local (Daytona) Craigslist and today there's a nice original '71 Bonneville for sale:



1971 Triumph Bonneville in fantastic shape. I have owned this bike over the past five years and have put much TLC into it and it is in great shape. A true survivor, it has never been modified that I am aware of. It is in perfect running and driving shape, all electronics, switches and gauges work and function as they should. I ride this at least once a week in my neighborhood. It recently had all bodywork repaired (dents dings in tank) and professionally repainted (in its factory original color) via Daytona Triumph. All services have been performed there as well. Clean title, everything above board. The 650 P-twin fires right up after a few kickstarts and runs like a champ with a perfect exhaust note. The only negative of note is missing the lightbulb for the tachometer which I am currently tracking down. In my opinion you wont find a better true survivor at this price. 69k original miles.

I would love for it to go to a home that will respect it and ride and enjoy it.

$6500 OBO

[speeder]

It looks like the '71 above was painted Astral Red as a solid color, the primary color on my 1970. It's too bad that they did not do a proper original paint job on it. I have nothing against great custom paint jobs but the original color themes on Triumphs back then were unique to each year and sub-model and identify the bike as such to the knowledgable eye.

A nice 1970 Bonneville just went for $10.5k on BaT last week, looks like mine but probably better mechanicals. Not for long, though. Doing a complete rebuild and learning Triumph engines quickly myself. They are very simple and wonderful. A major shout-out to Pelican Gizmofixer, (Paul), in NJ who has taken time out of his day twice now to give me an education on these motors. I also found a great British bike shop in Long Beach, BA Moto, which has the great parts business, Moore Cycles, just 100 feet away.

I brought my assembled case to BA Moto and one of the owners helped me get it apart with the special pullers and tools they have. These guys are great; they repair, own and race vintage Triumphs plus build killer race motors. They are young and I think they like to drink beer as well.

I've got it apart and the crank is at Marine Crank Shaft in Santa Ana getting polished and balanced as we speak, (one of, if not the best in the USA from what I'm gathering). My P/Cs were worn and had already been bored once to .020 over, so I picked up an Aerco 750 kit which consists of P/Cs, rings and clips plus head gasket. That ran around $630+tax.

Had a couple hours free yesterday to clean parts and get ready to re-assemble the case when the crank is ready. Here are a few photos taken recently. The bike:


The engine:




The new 750 kit, mocked-up on my bench:

[speeder]

Here is the old Triumph crank and the shop I referenced above, I think they know a thing or two about crankshafts:




Here is BA Moto in Long Beach, they build and race vintage motocross and desert race. A few shots of a bike they just finished:

[speeder]

Their cool shop:

[herr_oberst]

It's funny that even after how many decades, four 2x4's nailed together still makes the best bench cradle for a motorcycle engine.

[craigster59]

Originally Posted by speeder

Here is BA Moto in Long Beach, they build and race vintage motocross and desert race. A few shots of a bike they just finished:

Wow nice bike! That’s just great Denis. Now I’m going to be watching “On Any Sunday” tomorrow instead of spreading mulch like I promised the Wife.

Maybe if I get up early I can still get it done and be on the couch by 10am.

[Baz]

Thanks for the update and pics, Denis.

Very cool!

I just expanded my back patio to make it wider and built a whole new canopy over it and intend to use it for motorcycle restoration and repairs. I just don't have room in my garage and don't have a shop. The patio is 13'x36'!

Can you tell me what year and model this green one is? I'd love to have the exact bike!

[speeder]

Don’t know, I can ask. It may be a combination of parts and the motor is basically a high compression tt engine w Mikuni carbs and straight pipes. It also has aluminum rims that are replicas of Akront rims, if not the real thing.

The hottest set-up, (which that bike doesn’t have), is a vintage aluminum frame from Trackmaster or Champion.

[Jeff Higgins]

You can still get Metisse and Rickman frame kits. A riding buddy has one of the new nickel plated Metisses with a 650 Bonnie motor.

Metisse Frame Kits - Metisse

Rickman Motorcycles - Parts and Prices

[speeder]

Originally Posted by Jeff Higgins

You can still get Metisse and Rickman frame kits. A riding buddy has one of the new nickel plated Metisses with a 650 Bonnie motor.

Metisse Frame Kits - Metisse

Rickman Motorcycles - Parts and Prices

Very cool, thanks.

[speeder]

Ok, been a while since I’ve checked into this thread. I got the crank back from the balance place and have been assembling the motor as time allows. I had never rebuilt one of these, (or any motorcycle engine), now I feel like I could build one from a box of parts, including the transmission.

I’m just installing the 750 kit right now, (P/Cs), and the piston top to deck height had me concerned. There is a very noticeable gap @ TDC, approximately 1.5 mm or .06”. Does this look alright to anyone? Of course it will run but that squish band concerns me as well as CR.

Putting it before the experienced guys here.

[asphaltgambler]

That is a concern ^^^ if you want the performance that is designed into it. First question is what is the compressed thickness of the head gasket?

[asphaltgambler]

So I can tell you - .028" deck height including the compressed head gasket is where you need to be for that thing being 'snappy'. The edge of the piston is already .067 in the hole.

[sc_rufctr]

Looking good Denis... Enjoy that beauty.