Wildguzzi.com
General Category => General Discussion => Topic started by: dxhall on July 27, 2021, 08:56:17 PM
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I’m disassembling a ‘71 Harley Davidson Sprint. For those who don’t recall these, they were 250cc and 350cc single cylinder bikes made by Aermacchi, which in the 1960s and 1970s was owned by Harley. In the 1960s they were very successful race bikes in Europe, and were raced in flat track here.
Why am I doing this? Because (1)I can’t find a Guzzi single I can afford and (2) I could restore it to look like this:
(https://i.ibb.co/tPZ78Wr/6588-EF47-2810-4-CC2-87-FF-4-D1-D39-DB5-ADC.jpg) (https://ibb.co/tPZ78Wr)
The current problem is that I can’t get the cylinder head off. I’ve tried the usual tricks, but no success. Any suggestions?
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The head can be stubborn, probably the cylinder / head studs all rusted and binding on the alloy castings. Just soak the cylinder studs with penentrating fluid then start gently prying the head and cylinder off.
This is where I am at so far with my 1966 250 that I am building as a 1961 Ala Verde 250 Tribute, I have the Ala Verde tank, working on the 17" wheels / hubs. I am going with a Honda Black Bomber front hub. The forks currently on the bike will be replaced with the early style, circa 1961.
(https://i.postimg.cc/qMwLHY8R/624-BCB79-441-B-4965-9-FA2-3271-CD3653-C6.jpg) (https://postimg.cc/zVLWnx2Z)
The hopeful end result
(https://i.postimg.cc/QtKxRvj9/ala-verde.jpg) (https://postimages.org/)
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Piece of rope down spark plug hole then turning the crank…maybe….
Mark
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Does it run? :evil:
The cylinder head was stuck on my Enfield Bullet so bad that I bolted it back together without the head nuts, connected the carb and ignition, kicked it and BANG! The head was loose. :afro:
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Canuck750 - where are you getting your new parts? I don’t many places here in the US.
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I've worked on a few Sprints and owned a basketcase 350 for a short while. Bought the parts I needed on ebay and from Moto Italia.
http://motoitalia.parts/
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Seriously, stick the head / cylinder joint into a bucket of Coke-a-Cola, let it sit overnight. In the AM you will slide them apart using nothing more that your pinky fingers.
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Canuck750 - where are you getting your new parts? I don’t many places here in the US.
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Moto Italia, Leslie and Lancaster Aermacchi, Ron plus some stuff on EBay. Les supplied the Ala Verde tank and some other missing chassis parts. I bought most of the 250 engine parts from Leslie as well.
Cheers
Jim
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is it possible to hydraulic the head off? fill with liquid and turn the crank.
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is it possible to hydraulic the head off? fill with liquid and turn the crank.
See my post about putting piece of roop down into spark plug hole - a lot easier….
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Acetone and auto transmission fluid ATF mixed 50:50 and shaken well makes a good penetrating fluid. You need to shake well before each use.
Steve
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Penetrating oil on the head studs and much gentle prying got the head off. It’s not pretty, but is clearly salvageable.
(https://i.ibb.co/qNBdVj8/CF3-F8-FDF-ECE4-4382-880-B-1775-D6366361.jpg) (https://ibb.co/qNBdVj8)
I couldn’t try several of the head-removal suggestions because the piston is stuck in the bore.
(https://i.ibb.co/mzHVyHV/9-C10-DE93-DB8-B-44-FC-9-AFB-3476-FD70-D096.jpg) (https://ibb.co/mzHVyHV)
It looks like the piston rings are rusted to the steel sleeve in the aluminum cylinder. I’m thinking about trying one of those rust remover chemicals. Any suggestions?
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I've used treacle and water, although it is VERY slow (think weeks, not hours.)
https://www.youtube.com/watch?v=I_gsFx1XtsY
I've heard good things about Evaporust. I bought a can to use on an old Honda gas tank, but I haven't used it yet.
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Be careful with those rust removers. My son tried one on one of his Suzuki engines and it ended up badly. The Aluminum had been heavily attacked even though the literature stated it was safe for aluminum. The block is junk now.
The pistons/rings were also frozen in the Suzuki's bores but I hit it ATV / Acetone for a couple of days, modified a doug fir 2x2 to fit closely and with a couple of whacks with my single jack (4 lb sledge) they came out nicely. Of course the block was supported on a wood cradle that I built.
I've found penetrating fluid works really well if you use it then let it sit for a day then use it and let it sit again.
Carpenters do things with wood and I knew wood would soften the initial impact and hopefully not bust up the pistons.
Mark
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Acetone and auto transmission fluid ATF mixed 50:50 and shaken well makes a good penetrating fluid. You need to shake well before each use.
Steve
I would try this. The theory is the acetone makes this into a liquid that wicks in really well. It the evaporates leaving the ATF to work as a penetrant.
Steve