1961 Aermacchi 250 - Harley Davidson

Well I went and did it again.

My Harley friend called me up last week and asked if I was interested in an old Harley sprint project a customer of his had in his car.

I was, so I got the guys number and finally met up with him today.

It was reasonably priced, and heck I don't have enough projects :roll:

So here it is. Don't know what I'm going to do with it yet. It is quite the heavy little beast.

I'll start buying the missing pieces, of which there are only a few. Wheels, tank, barrel and seat.

I would like to find a fairly complete one. Very few of the parts are in common with the Ala D Oro, however the bike would make a lovely cafe racer, and there is a racing precedent for guidance on looks.

I was under the impession that the Harley Sprints had lower frame tubes added?

acotrel said:

I was under the impession that the Harley Sprints had lower frame tubes added?

Click to expand...

Later model 350 "knuckleheads" did, I believe...

...and by "lower", they're really just a pair of intermediate tubes to hang the engine from (engine mass stays below the "lower" tubes). The only support underneath the engine is at the rear from the main chassis root.

Quite a number of pic about on the inter net; mostly racers;

http://www.bing.com/images/search?q=196 ... ORM=HDRSC2

http://www.vintagebike.co.uk/pictures/1 ... -ala-doro/
http://www.vintagebike.co.uk/pictures/1 ... cchi-250s/
http://www.vintagebike.co.uk/pictures/1 ... -ala-doro/

I don't think the added tubes has anything to do with the motor, were bracing to help the handling, and mainly for appearance? The early 250 Aermacchis had forged plates as part of the frame. I think Harley Davidson make good tractors, they should stay away from real motorcycles.
http://www.aermacchi-racing.com/

Congratulations. It will be sweet. Good machines.

I am currently researching what I have. The frame and 1 engine is a 1961.

The spare motor is a bit intriguing.

It is unstamped, has a magneto ignition, larger clutch, and is a short stroke.

There is not as much out there on them like a Norton.

But at least there is some stuff, just harder to find.

bwolfie said:

Well I went and did it again. It was reasonably priced, and heck I don't have enough projects :roll:

Click to expand...

I thought I was the only one who did this.....trying to change my ways though...wife and kids are helping me to change because there just isn't enough time anymore :shock:

Does the spare motor have a 5 speed box ? Might be an Ala D'Oro racer ? I once rode a friend's 350 Drixton Aermacchi - very convincing argument.

I won't know how many gears it has until I get it freed up.
I pulled the sump plug and was greeted with smelly goo.
It had that distinct odor of a 2 stroke model airplane engine that hasn't run in 20 years. Old caster oil.

Consequently the motor is very hard to turn, so it is now soaking.
I'll know more once it has freed up.

Sorry to hear that, but if it is vegetable oil it will require a complete engine strip to get rid of this old stuff.

I was planning a full tear down anyway because my X-ray vision isn't functioning. :lol:

I don't trust the guts of 50 year old motors that I don't know.

I wonder who would use castor oil in a street bike ? I'd be having a close look at that spare motor, does it have an air cooled clutch ? The head on the racing motors was a slightly different casting, however I cannot remember the detail . Very few parts are interchangeable between the Sprint and the racing motor. Aermacchis are really good machines. The Drixton my friend owns is really exciting, and he also owned one which was ex-Charles Mortimore, a while back. It is still around somewhere in Melbourne.

Got it opened up. it's just a 1966 sprint engine. 4 speed, dead simple inside.

Better luck next time . At least you are playing with something decent. You can make a very nice bike out of one of those . Don't expect it to beat two strokes in a race, however It would have soul and panache.

Acotrel:

Whne N-V first tried to sell the AJS Stormer as a "street/trail" bike, the test shop had just discovered an incompatibility with regular engine oil in the gas. I'd been doing quite a lot of street riding, in-town Wolverhapmton and the 12 commuting miles or so to where we lived. Quite early on (about 1000 miles), the engine was making an odd "ringing" noise.

We did a tear-down, so I had to ride the bus to work. We found circumferential ridges in the cylinder liner. They didn't go full circle and were concentrated around the exhaust port. When we looked at the outside, we found broken cooling fins around the exhaust. We did some dyno tests and discovered that we were getting pre-ignition at low throttle openings, and the area around the exhaust port was getting cherry red.

We finally concluded that there was a breakdown in cylinder lube due to the high temps and that the piston rings wer very briefly wleding themselves to the liner, then breaking away again, each time they passed over the hot spot. With Castrol R, (castor oil) it didn't happen, so the early production deliveries went out with the caution "ONLY USE Castrol R". always close the petcock when you park the bike and give the bike a good shake if it's been standing more than a couple of hours. The reason for that was that the oil didn't dissolve in gasoline but went into suspension. You'd get neat castor oil in the float bowl otherwise.

After I left, they must have solved the problem, as I don't recall any mention of the instructions by friends who bought Stormers.

How do you get Castrol R off your motor after it has turned your bike into an instant dirty shit heap ?