The Hercules rebuild - Engine and other antics

[nisp]

Bringing her home:

While stumbling the classifieds I saw myself looking at a picture of a shipping container filled with classic motorcycles when I saw the words “Hercules” written on a fuel tank. With not much to go on I thought it was worth a look as it could be one of the fabled rotary powered bikes, The 502. It wasn’t.. However, talking to the owner and seeing many parts scattered around the place it transpires it was a GS 125. A 125? WOW.. Not… although hold on. It has a 7 speed gearbox. Whilst I usually don’t go for anything below a 250 two stroke this 125 smoker produces 22hp which is above my minimum required hp of 20. So I bought it as its an interesting marque, it’s a 2 stroke and the quality of the materials is very good.

Its home for the last 6 years:

https://i.postimg.cc/qBjNCQc9/IMG-20240704-214738.jpg

After shelling over some money, it was time to take it home. In preparation for this I removed the bolted rear seats out of my Chrysler the day before. The packaging could have been better but some of the internal structure below of the cars rear window got in the way. Nether the less I was and did get the Hercules in one go in the back of a 300c.

Ready to go in the car:

https://i.postimg.cc/2j4wRpDn/A1A12132.jpg

Yes officer it is in the car:

https://i.postimg.cc/s2kpqmHn/A1A12134.jpg

Interior, surprisingly roomy:

https://i.postimg.cc/rsJxdkVb/A1A12137.jpg

Once home It needed a bit of a scrub with a sponge as dust and cob-webs had accumulated on it and by god I wasn’t having any more spiders in my house. With a quick sponge bath, the frame was actually pretty clean as someone started the restoration, got the frame powder coated etc then stopped. So, with that, It now lives in my bedroom as opposed to the one falling down barn (for 11 years) and one shipping container (for the last 6 years).

A good OL’ Sponge bath:

https://i.postimg.cc/15mDkfMZ/A1A12139.jpg

The Hercules’s new home (The engine is in the kitchen):

https://i.postimg.cc/RFTNdLkJ/A1A12175.jpg

The plan is to put it all back together and use it for some light enduro, classic ride outs etc. if it behaves very well it might see Morocco.. but I can dream.
As of last night. Day 1 Night 1. I cracked open the horizontal crank case and am in need of a few more parts than expected. I knew this would happen and have already joined the Sach/ Hercules owners Facebook group. Already people have come forward to help. The bike was born on the 11th of February 1976 with its engine being made on the 13th.
Two days after I brought the bike home several repair manuals and such are being downloaded curacy of the owner’s group and begins the arduous task of acquiring parts from seemingly all over the world. Luckily I have a German contact who I met in Cologne (he thought my MZ was an interesting choice of vehicle as he didn’t know they were exported to the UK, he also laughed at me for wanting a Trabant.. ) and has volunteered to find out if anyone has some parts at his local classic motorcycle meet.
There is lots of parts to source, lots of documents to read but I would like to keep a record of the bikes process and a record for others as I also need to register it with the DVLA. Registering is something that I would like to learn as I imagine there are a lot of hoops to jump through, but it opens other vehicles avenues in the future and is well worth learning the process.
Has anyone got any experience that they can share about registering a dormant vehicle before NOVA was a thing?

https://i.postimg.cc/kgZ8RwCn/A1A12142.jpg
https://i.postimg.cc/zfghCWDT/A1A12144.jpg
https://i.postimg.cc/Hx1yBxjR/A1A12148.jpg
https://i.postimg.cc/cCXtxBTG/A1A12150.jpg
https://i.postimg.cc/CMNqsw0r/A1A12151.jpg
https://i.postimg.cc/gktL14nv/A1A12152.jpg
https://i.postimg.cc/y8J3K9Z2/A1A12154.jpg
https://i.postimg.cc/rpxd0kgJ/A1A12155.jpg
____________________
Suzuki TS 50 1999 Honda CB 125 t2 1981 Yamaha XJ 600 s Diversion Honda cx 500 MZ ETZ 250 1985 Yamaha FZR 400 1981 Suzuki TS 185 1984 Triumph bonneville 790 2001 MZ TS250 1979 Suzuki sv 650 1999 KTM exc RFS 450 2007 Hercules mx 125 1976

[stinkwheel]

Now that'll be an interesting project.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[A100man]

I suspect you'll have to get it SVA'd if it's never been registered before..

..an experience I wouldn't care to repeat.
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[nisp]

Delving into the engine and other antics:

After sending off an application to the NOVA office not too long later I received an email with “I am pleased to tell you that you can now register your vehicle with the DVLA”. Great, no need to pay anything to the man.
With Nova ticked off the list after more digging, I believe I only need a few pieces of paper to get it registered.

NOVA ✓
Date certificate - pending the engine rebuild
DVLA registration form - have the form
Historic tax application form - easy
MOT exemption form - supereasy

Being an MZ fan and an avid two stroke fan I already knew of the British two stroke club. On the website they say they are able to date machines and provide a certificate for the DVLA. So a quick phone call later and I asked the dating officer how they go about it. The answer was basically I troll though the internet, archives, ask around until I find the bloke with the records. Well then, I said, I’ve done you a favour and already found that bloke for you! Another great result. Strangely though the man who initially dated my machine though the Hercules fan Facebook page didn’t want to give any more information to me and said that I can ask my DMV to give him a call…. ?? So yeah… The British two stroke club to the rescue! There is a caveat though in that the machine has to be in running order in order to get the certificate. But that’s okay I can do that.

https://i.postimg.cc/c4N6jmbZ/A1A12183.jpg
Engine disassemble

https://i.postimg.cc/j57d3w6L/broken-gear.jpg
Broken starter gear teeth

Using the parts catalogue found online for the Sachs engine I was able to identify all the missing parts that the previous owner said are unobtanium. Dam straight probably why it spent so much time languishing on the European continent before it languished some more in a falling down barn and later a shipping container. Looking though German equivalent of eBay and using my German contacts, I found stuff. But not everything. A chance glance on eBay reviled a single clutch basket, I have learned doing several bikes that like me these people with obscure parts usually have more of them. I was right. Two months went by confirming part numbers, there were yes’s there were no’s and we settled on a list of parts. Time is getting on at this point, I know this he knows this. Then. Nothing. MIA. I honestly thought he’d departed or something. With an obscure bike like this the people who one them are certainly not my age.
Then, one day over a month later. I get the message. “buy this one first. Then we’ll talk” BRUV I’ve been speaking to you for two months already where’d you go? Ominous I thought but didn’t matter *Presses buy now* immediately. Two weeks rolled around, and I get a very small parcel at work, it’s not unusual as I get loads of things delivered at work. What was unusual was the letter and small metal bar (part of the clutch actuator). The letter explained that he was trying to contact me on my mobile number as the delivery details would have such things. Although where I’m currently based there’s no decent phone signal ever and he didn’t get though. But it was okay. I now had his number. And I had a return sender address just in case the phone didn’t work again.
I couldn’t get to the motorcycle show in Stafford to meet up to collect the parts but were on a first name basis now and I’m going to collect the parts as I’m travelling back and forth. I have an address I have a time and I knock on the door. Promptly gets shown to a non-descript white van. But its okay, he’s just returned from the show and is carrying a mass of bike things. Truly a lovely guy and we start talking about vintage endure and almost three hours go past, I have tea and biscuits inside. This house/ garage where I am currently is owned by a person who used to specialise in Sachs engine parts and he had every piece that I really desperately needed. After being told how rare the machine is and that engine parts couldn’t be found I am now 13 miles away from the shipping container that I bought the bike inside!

I have obtained the unobtanium:
0658 006 000 clutch hub
0649 110 000 Clutch push rod X2 Note- there is another part to the clutch actuating rod assembly- #0632 127 000- I have that part also.
0644 122 000 Crank 1/2 washer x 2
173 144 001 K/Start return spring washer
116 000 K/St spring
0658 010 000 Clutch plate X 5
0658 009 001 Clutch plate X 4

A strange and funny story, and I just paid what he was asking and am in contact about future enduro events and the possibility of buying a Motorplatt ignition stator as apparently, they are rubbish. It’s okay, his mate has about 50 of them so I’m told. At this point I’m thinking you can’t make this stuff up, alas I have another story about the crank that I will share in the future.

The front forks needed to be re-hardchromed as I’d rather have the original parts and the quality of them is like nothing I have seen before and especially on a 125. The forks where hard chromed in Birmingham by a place called “Davies precision grinding” would defiantly recommend. Cost £230 for both legs to be done but I think well worth it as I don’t want Chinese copy legs folding on me while I’m out in the middle of nowhere. To get the legs on the machine though I now needed to clean, prep and paint the yolks. I used a ceramic type paint that needs to be baked in the oven to give it durability and am impressed by it so far. The engine cases were also done in the same stuff.

https://i.postimg.cc/SKXyj2vD/fork.jpg
Dirty fork in the works parts washer

https://i.postimg.cc/k5k7SMr9/rebuilt-forks1.jpg
Clean forks reassembled in the kitchen - fun fact, these things have two fork seals each. 4 double lipped seal in total, never seen anything like it.

https://i.postimg.cc/sX7s4FyW/rebuilt-forks2.jpg
more fork goodness

https://i.postimg.cc/SQLmXpgF/A1A12671.jpg
silver parts in the oven

https://i.postimg.cc/k57QmCYJ/forks-on-again.jpg
Hercules with feet

And now Hercules sits with two wheels on. Not on the ground though thanks to its brilliant centre stand.
I’m trying to document this in the order that I am doing the work but at the same time as the fork rebuild in the kitchen I have been doing thins after work to keep things chugging along.
Here are some pictures of the magnesium side cases before and after paint. This bike just has magnesium seemingly everywhere from what I’ve read. Again, the quality and thought of this machine is jaw dropping and must have been expensive back in the day.

https://i.postimg.cc/6qzsMtP8/timing-case.jpg
Ignition cover

https://i.postimg.cc/qqpVcz1f/clutch-case.jpg
Clutch cover

https://i.postimg.cc/B6Tf1xcc/cases.jpg
Freshly painted cases

In my lunch break I have been taking replacing the bearings on the gearbox shafts. One came off easily but the other I needed to remove all the gears. With a clean and reassembled with the aid of some grease to hold it all together both the gearbox shafts are ready to go in the freshly painted little engine. The crank took some work and I had to buy a new puller for the ones next to the counterweights, but I have been needing a verity of pullers for a while so it’s not a waste of money.

https://i.postimg.cc/kg6ZbQ76/crank-diss.jpg
Disassembled gear output shaft

https://i.postimg.cc/mgvnNPrd/gear.jpg
Gear rollers before cleaning

https://i.postimg.cc/fbYrHMtM/gearbox-shaft-dissasemble.jpg
Crank that needs disassembly

The crank has been abet of a challenge. One, finding a place that can do it. Two, finding a place that will do it without wanting to replace the conrod. I phoned a place in Birmingham and they said that they can do it as they specialise in old two stroke. Perfect, “and what bike is it Sir”, “it’s called a Hercules”, “Never heard of it” so much for that place. But I do have a challenge on my hands and I need to try another place. And so we enter the twilight zone where on a Friday afternoon after many failed calls google says this place is open till 5pm. Amazing, I’ll just go down there. Enter “autocycle engineering” there website is lovely outdated by todays standard but has a lovely charm to it, easy to use, everything’s pretty obvious to find. An hour later though Birmingham I stand before the following:

https://i.postimg.cc/T2tHN7w5/strange-occ-2.jpg
An old factory

On the door is two massive padlocks. Its pretty obvious no ones in but the sign tells me that if this door is shut then go to the other door. Righty ho. That door tells me to try the other door. I walk back. Studying the door again there is a little paper note that reads something like ask for Ian in the house over the road. I knew this place was shut at the moment, but you need to gather all the information you can at this point so that I don’t waste another two hours driving across Birmingham. I walk across the road, confidently asking for Ian, promptly getting a blank face from the woman who lives there and clearly she isn’t called Ian. A man is visiting a house also over the road. Clearly I don’t belong there and I ask if there is an Ian in that house because I’m trying to get into this place.. nope, No Ian there either actually called Scott... I’m just laughing at this point as he said not in this house or the one next door, surly someone is having me on. I get some information about a white house. Just around the corner from the picture is a house that can be described as a town house, with no other houses next to it. It’s a pretty strange thing to look at. I get information about a red van… I thought while I’m here I’m getting everything I can and tried one final house over the road looking for the mystical Ian. Nope. He’s bob and knows Scott because he rides vintage scooters. But as we were talking, he’s like yeah I’ve had a Hercules. Come on Bob your pulling my leg. Basically, he didn’t have the mobile of the guys who own autocycle engineering but thinks they must be relocating as equipment and stock is moving. But I will try to contact them again and ask them to do my big end crank bearing as their website mentions the word Hercules at least twice.
I never found Ian, no one knows who he is and he doesn’t live across the road.

I’ll leave it there for now. I should have parts coming from Austria, Canada and some other place that won’t deliver to the UK so I will be sending them to Prague. How fun.
____________________
Suzuki TS 50 1999 Honda CB 125 t2 1981 Yamaha XJ 600 s Diversion Honda cx 500 MZ ETZ 250 1985 Yamaha FZR 400 1981 Suzuki TS 185 1984 Triumph bonneville 790 2001 MZ TS250 1979 Suzuki sv 650 1999 KTM exc RFS 450 2007 Hercules mx 125 1976

[A100man]

I was so intrigued I searched Google maps for AutoCycle Enginnering.
In the same street or possibley the same building is Ian Bennett engineering. He has a web-site too.. vintage bike oriented.

https://www.bennett-cnc.co.uk/


Good luck!
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600