Aermacchi Motor Assembly // Paul Brodie's Shop 

Thanks for the presentation. Back in the mid-'70s my buddy had both the 250 and 350 Sprint variants. We used to have a blast with those bikes. He was into extended wheelies and sometimes had trouble with oil starvation to the top end.

I would LOVE to see that Ducati single on the shelf behind you get rebuilt. Those are a shimming hell but it always makes me smile to see it behind you.

Man, there's a lot of ''why I didn't think about that'' kinda special tools in your videos. I just love how you make us think differently about tackling a problem. Keep it up Sir!

Paul and Mitch, another great video...thank you. Paul, Here’s a cheeky request for a couple of books: one, with your wonderful sketches/drawings, and another, a catalogue of your special tools, including a photo or sketch of how it’s used. I know you are a busy man, but one can dream!

Great work. l had an aermacchi in the early 70's. Wish I still had it. I'm into British stuff now mainly Nortons. Just a suggestion. You can use the piston upside down in the bore to square up the rings to check the gap.

Thanks for the video. I always liked the look of the 73 and 74 engines. 👍

Lots of small and tricky parts to those engines. Looking at all the special tools you need to make it is not something you can "just slap together". Great job on the engine and videos.

My favoritest Kanukistani bike builder, it's always a special pleasure to be back in your shop for another half hour or so.

Thanks Paul, Friday night saved!

The Bob Ross of engine building!!

Awesome to see the engine together! Thanks for letting us in on the project

thankyou for a great half hour`s viewing dynamic duo, 😊👍 the custom modified essential toolkit needs patenting! its great to watch people who know what they`re doing! i "love work,i could sit and watch it all day" 😉😇 another excellent instalment paul and mitch, thankyou both!

Sir you are a Genius, you always over come your obstacles. 👍

You're smile says it all.

An engine and a sculpture all in one❤️

Great video! I'm bringing slowly a 1998 Ducati Monster back to life, not much in common but your dedication and ingeniosity are such an example.

Dear Paul, thank you very much! Now I can assemble my Aermacchi. The bad thing is that when I see you do them they look easy but when I do them it's torture! I'm glad you're well! Keep up the good work!

Thanks Paul and Mich. Another great session !

The marker pen an engineers best alignment tool. Nice vid.

3 minutes into the video and I hit like button. That multi-keyway gear is ingenious.

See you eliminated the tab washer under the clutch basket, I find the conicle nut solution you made very good as this way the nut grips the thread. IMHO tab washers are rarely a good idea because they are made of soft metal which often compresses in use and reduces the torque on the fastener.

Hello Paul, I really like the fix you worked out with using the bevelled nut, very neat. Like many others I suspect, I think your special tools are just the best. When you see them, it makes you think that’s a simple idea, but that’s what is great about them! Great video, and so good to see you looking well. Best wishes Kevin.

Always great to see you on the workbench!

Such beautiful castings on that engine! They actually kind of remind me of Campagnolo bicycle components: functional but beautifully designed and finished.

I can't wait to see that baby blazing around a track! I said it before and I'll say it again, the whole machine is a work of art! Bravo!

Paul you genius! Thanks for the new vid, is always good to see you!

That was a rather elegant solution for the clutch hub nut, I like it For the rocker arms, a trick I learned from working on Honda CB500/550 fours, rubber band around rocker arm to hold them up (On the Honda, the adjuster screw can (and does) drop to edge of valve stem and when you tighten rocker box down it bends valve(s) and if your really unlucky, crack valve guide top It's not something many people think about with an SOHC motor, but, you never do it a second time. One other thing I learned from Harley 'race' motors, have the 'split' in the valve collets (cotters?) in line with the rocker arm, if anything goes wrong when over revving (valve bounce when rocker arm may contact spring retainer) it's less likely that a collet can jump out. I've never actually seen it happen but anything that can go wrong on motor will go wrong at some time?

Superb build Paul, your special tooling is art. Some fantastic ideas there. The 'adjustable pushrod' is inspired. Best wishes, Dean.

Very enjoyable video. Thanks.

Yes, very lucky Blumin V 12 at the moment we are currently rebuilding the two engines on 1000 hp Sunbeam land, speed, car, first car of 200 mph we have two, 475 hp Sunbeam Aero engines in there, so we have 2V 12 to work on originally the engines run a powerboat race in America in a Harmsworth trophies. Were we have four Sunbeam engines unfortunately crack to Hull, and it never raced in fact, it’s sunk to the engines have got quite a bit of history that’s long before I got involved in them, so I do know where you’re coming from. Enjoy your program, Michael

Every episode I learn new ways of assembling motorcycles. I love watching your thought process, problem solving and creativity to make your job achievable. The special tools are simple but highly effective. Thanks Paul. You know what I will be doing today in the shed . Making clutch and sprocket tools . Cheers mate from Australia 🇦🇺

What do you use to get all these parts so clean?? Love the videos

I can't wait to see how much power this makes on a chassis..... Such a beautiful motor. Great work guys... Keep it up. 😁👍

Top shelf video Paul. Gets my mind working and love the ‘special tools “. Cheers!

You're such a humble man. I love watching a master of his craft at work. You're also looking well there, Paul. I hope all is going in the right direction. God bless you, fella!

Hi Paul!!! Just to tell you that since you are missing i watched all the previous episodes back again. Definitely tiger cup cockpit is a masterpiece . Hope you find well and you recover soon. Thanks fede

Nice! I like the special tools. At 12:02 unless you used a reverse thread allen screw the safety wire is attached to the wrong side of the allen screw.

Got my Aermacchi because of the external banjo bolt, oil line setup was a leaker, the mouth breathers over torqued it by 100 ft lbs it was just a single oil line perhaps 1967 maybe, cool bike but the shifting pattern and controls were at first challenging not similar to most bikes, handled nice good low center of mass. Great production you guys always knock it outta the park.

Nicely done lads!

Thank you Paul and thank you Mitch. Greetings from Germany

that is pure and unadulterated art work, and you are my favorite artist. thank you for sharing your process. so happy to see you back in your shop also.

I was thinking "Special Tool" needed to be a drinking game for this episode! I tried to buy you guys coffee, but the payment service kept throwing errors. 😞

There's a new tee shirt, "I made a special tool"

Thanks for the vid, I remember re corking clutch plates with my Dad, old British bikes, you bought the cork in sheets and cut the pieces out with a razor blade to fit in the plate. Used to take hours, anyone else remember doing this.

Your Safety Wiring on the oil plug is spot on.

Very beautiful motor!

Another great video Paul. Thank you for the time and effort you put into these. I learn a lot. I’m amazed at the custom tools you make and how your able to machine things so accurately. It’s really impressive 👍And I’m super happy seeing you doing what you love to do and looking healthy 🙏

Paul, outstanding work as usual. Thanks again to you and Mitch.

Mantra for this episode: --- so I made a special tool.

Great work, Paul. A lot of fantastic tips. It's nice to see you looking well.

Mate, I've run out of superlatives. No matter how good -- or bad -- they are, every mechanic, engine rebuilder, and backyard bodger should be made to watch your videos. Surely they'd be inspired.

Great video Paul …what a beautiful engine

Excellent video! Did Aermacchi ever go with a chain driven overhead cam? It seems that would be almost an impossible job to put the push rods in without a special tool for a home mechanic. I wonder how the shop manual describes the installation. Did Aermacchi ever have factory race teams using this engine. You would think if they needed a 15 tooth front sprocket that would be required for a higher top speed for racing then the sprocket cover would have been designed that way...just a thought. Nice looking engine with a low center of gravity. Wonderful job for this video, thanks to both of you!

Hope to see you soon in another teaching video Paul. My thoughts and prayers are with you my friend 🙏👍

Another fine video! Thanks Paul and Mitch for sharing. Your ability to make the special tools needed inspires me to do the same with everything I build and play with. Keep them coming and we will keep watching! Enjoy and be safe. And thanks for another "That's a good fit"!! I have my "That's a good fit" hoddie on today! Always make for a better day.

I hope you find well. I watch all your videos they are extremely enriching. I wish you the best and that you recover soon. Greetings from Argentina

I am rebuilding a 72 SX350 and am thoroughly glad seeing your detailed build videos. Glad you're back in the shop and hopefully on the mend. I am trying to get my crank rebuilt if you still have contact with Leslie w/ Moto Italia I would love to see if he has a connecting rod assembly. Thanks Paul, keep it up!

I love all the special tools - something I do as well......Thanks as always.....

I hate to be a nit picker but, having worked on helicopters for almost 50 years has made me so. Good idea to lock wire the filler plug but, the screw that you put in to wire it to is anti locked. Nothing would ever come of it but,,,. Great video. You are a master and i am paying attention.

I have the factory special head wrenches for Ducati- but needed a different one for an AJP engine I overhauled. Easy to make, just weld an old socket onto the wrench, then you can use a torque wrench at 90º and have accurate measurements. I’m sure you can come pretty darn close by hand, but it is easy to do by spec too. I was going to add picture, but does not look like I can. I would not have thought of the adjustable pushrod- great idea to save a LOT of time.

Nice motor!

Hi Paul and Mitch . Excellent video and education , thanks muchly , I really enjoyed it . Loved the special tools ..... the head to cylinder/block bolts are rather difficult to reach , but would a crow's foot wrench be the tool for the job ? Since these fit onto a socket extender , you would be able to use a torque wrench too . That said you may still have to shave off some height on a crow's foot for this particular job ; depends on which tool you buy I suppose . I do like your push rod alignment tool ; what a pain of a job , without ET fingers ! Would a magnet help ? Lol

Thankyou for your channel as an retired machinist I am loving watching your week in the shop. I have a 1o68 Honda CD 175 in about a thousand parts. You have Inspired me to start again and restore it

Upps! Your safety wire from the oil fill plug to the head of the allen screw was on the wrong side if the allen screw head. If the filler plug loosened it would pull and loosen the allen screw also.

Hi Paul hope all is well. Wory when your not teaching us.

The better the valve train is set up the better the motor will run. 🏍🏍🏍

beautiful motor i have always wondered about the inner workings of a Aermacchi..course with your enhancements makes them even better.

I will definitely be building a tool like yours to adjust valves . Home made tools are very interesting and you dont disappoint. Thanks once agin for teaching me something.

I was waiting for the angle measurement. Paul never disappoints.

Dig it!!

Paul I know what you mean I once had to make a cylinder head bolt tool for a Fiat 128

The safety wire is on the wrong side of the stud for the oil filter plug.

11 mm the Italians liked 11 mm . Struggle to find them in stores.. ps watching your old shows a second time.

Wahoooo! Another video finally!

A very good video on engine building and getting things right. Valve spring seat pressure is something many people neglect but just as important is getting a spring that is matched to the cam. In the worst case the spring can coil bind resulting in a bent pushrod or damaged cam, especially if you gone for a higher lift cam.

Great to see you Paul , your looking well mate 😎😎🤘🤘🤘

An 11mm nut... when the vanishing 10mm mystery meets a design.

Paul Following on from your last engine build video when I asked about the clutch retaining nut and direction of thread I think you have answered my point if the spin of the clutch tightens the retaining nut then you do not meet a tab washer therefore giving you more thread engagement loctite is a good safety backup though if you look at captive rear wheel spindles on modern race bikes they do the same thing no spilt pin due to the wheel spinning and tightening up the spindle. Great video and good to see you so well. All the best Jon.

G'day Paul, Thanks for another great video. I have 2 comments for you. Sorry, 3 comments. Longer springs are weaker than short springs, particularly if the longer spring has more coils. If they have the same number of coils, then they will have the same spring rate - the longer springs will have more travel before coil bind occurs, but they will also twist further. Valve springs do not provide a seat pressure - they provide a spring force. Pressure is a force over an area. If the spring is pushing against a piston, in a closed cylinder, then spring force on the piston creates a pressure in the cylinder. Note also that the specs called for 80 lbs, not 80 PSI. Finally, are you sure about the cam timing? Advancing cam timing increases low end power, & decreases top end power. Retarding cam timing increases top end power with a drop in low end power. It also moves the peak torque RPM closer to the peak power RPM, & works better with a close ratio gearbox. Anyhow, it's always good to see you in the workshop. I'm looking forward to the your nexy video. Andrew

Paul ,,,, your a tease ,,,, in behind the camera etc you cant see him but I can .... We all want to see Mighty Mitch ,,,, lock the shot Mighty one and do a cameo .

my good fit is done with a FBH lol

Drilling in a tiny tap in pin into a clutch nut notch may appease the Loctite Fearful.

always an masterclass! thankyou!

Spelling error with "Link in the desricption". But I prefer it spelled that way anyway.

Love your videos! I’m restoring a 66 250 C and was wondering how far the piston edge sits down in the hole on stock engine? My replacement sits a few mm in

You can measure cylinder head nut torque by standing on a bathroom scale.

Pure joy! ❤

For once there is a man, whose amount of special tools is greater than that of Park Tool's. Keep it up =D

Noticed you never use a torque setting tool on any of the fixings also the play on the gears seems excessive unless the specifications allow it.

Thank you

I hope your doing okay Paul🙂

Hi Paul, how are you? Hope all is well.

What! you made a special tool? :)

I actually think your humble pushrod lifter is your most brilliant "specialty tool", as I've never seen anything like it before, while all the others are a fairly standard variety as used on other applications. Now a "details" question: have you tried gasket shellac rather than skim coats of sealer? Is the sealer preferred as it fills surface irregularities, or is it just "how you do it"?

I cut something on my lathe last night and while I test fit it I mumbled “that’s a nice fit”. I blame you.

Awesome work Paul! Are you running standard valves? I recon the factory would have struggled to build such a nice looking engine on any of their racers :)

I never realized head gaskets were a thing that an engine could not-have, does it have some alternate way of filling the purpose, or does it just not need it somehow?

Do you rebuild Sprint motors? I have a 1972 engine with a 1973 barrel, head, pushrods, cylinder studs and 5 speed transmission. I would like to have it all assembled together. Thank you.

No lube on the cam lobes or gears? Love your stuff, Paul. Thanks for supporting Ukraine with your little flag in the background!

Hey bud, can I replace the generator shaft oil seal without splitting the cases? Thanks