Puch Monza - From San Francisco (USA)

Hey Cats,

I think the Google is doing a horrible translation job! But thanks for all the nice words. :)

I have been running a Gila, with the HPI inner rotor, and a Mikuni. The RS50 JollyMoto pipe on it was the real trick to bring all of that stuff alive. You really have to have all of the components to make it work.

The upgrades, if you can call them that are really just side grades. The top end is the same, the ignition, is about the same, but has a usable accessories circuit. The carb is about the same as the Mikuni. Same size, and style, but has the same jets as my other bikes. The Mikuni needed a rebuild, and the parts to rebuild are close to what I could get the PWK for so I went PWK. But really the bike will have about the same performance--which is to say amazing! :)

This is such a fun bike I'd be so happy if my buddies in Spain would try putting these parts on your bikes too.

The one big problem that I haven't really solved was the clutch. All this power rips right through the clutch discs!

Well today I decided to do some learning about head lights. That's going well enough, and I'll be posting about it once I've got it worked out. But I also learned about some way cool stuff for the Puch 4 speed engines.

There's a Puch parts website that has all sorts of engine parts for these bikes. New stuff too. It seems like they might be called Puch Shop, but the website url is puch-ersatzteile.eu. <--Link

In April they announce new clutch baskets for the "Monza" engine. This is super rad, and do I want one!

Puch Clutch Basket <--Link

New clutch baskets for Puch mopeds

April 21, 2015

Puch moped clutch baskets
In all Puch mopeds with 2- 3- or 4-speed gearbox, the clutch sits on the crankshaft.
The thus rotates with the crankshaft speed and during sporty driving, the clutch discs hit in the clutch basket a. The is therefore a wear item and must be replaced from time to time. Since we have exhausted all the remainders, we had to take care of a new production us. Together with Western European partners, and it is able to offer the best quality at a reasonable price.
Here`s to the clutches

The clutch baskets are turned from solid steel, gefäst respectively, then brünniert and pressed with the helical gear. The high-quality finish underlines the quality of the execution. To ensure the optimum performance, a new thrust washer is provided, which must be replaced with the old one.

But there's more! They have high end cranks too!

Puch Cranks <--Link

Reinforced crankshaft Puch 3 / 4GG. Kobo 12mm
SKU 329.2.10.015.R
reinforced crankshaft Puch 3 / 4GG. Kobo 12mm
More Views

RITO crankshaft,
- Very robust due to reinforced crank pin
- High quality
- Voids with aluminum closed.
- Ideal for performance enhancement
- Can also be installed in any "normal" engine

€ 139.00
Quick Overview
RITO crankshaft crank pin 16mm (instead of 14mm) Auswuchtborungen filled with Alupfropfen, to increase the pre-compression.

This is great news for our bikes! :D

Tora magnificent job.
How many hours have you spent on the Monza ?

Hours! You have to count the time on the Monza in years.

Thanks for the complements. Right now the Monza is looking pretty shabby. It's been hit by cars, and vandalized by evil people. But the Sacto rally is coming up soon, and I'm actively getting the Monza back in shape. Although I have been playing around with this project--a Derbi GPR for the kart track:

Well I didn't make it to the Sacto Rally this year. :( I had some trouble with the Monza that I just couldn't deal with in time. After getting the parts for the update I took the Monza over to my friend Greg's place to do some wrenching. Sometimes he'll have wrenchfests where he invites a bunch of cats over, and we work on our bikes. It's a good time. :D


I knew I wouldn't be able to get everything done so I focused on the HPI, and getting the lights going. I came up with a really cool solution for the light. Now that I had the HPI mini rotor I would be able to power good lights. Previously I tried an LED solution, but even that was too much for the HPI inner rotor. The Mini rotor though puts out 55 watts so it could power a low watt H8 bulb. I also got a connector for it (the one in the photo is the wrong one, I had to go back and get one for the H8). I haven't tried it yet, because I need to wire up the regulator rectifier. But I got light installed and ready to go. :) I also did a re-wire of the tail light as that needed fixing too.





The following Sunday was the Creatures annual BBQ ride. They go on a moped ride, then meet up in Golden Gate Park for a BBQ (thankfully they have veggie stuff too). :)

I was able to make it out to the ride start but my bike was running poorly. I tried resetting the ignition, and that helped. The bike became more ridable. But the bike was still unhappy.


On the BBQ ride the engine seized (because I rode it too hard), and I had to get a ride home. The tow truck driver really wanted to make sure that the Monza wouldn't be moving around!



Once home I stripped down the bike. I pulled the engine, and brought it inside for later inspection. The Monza is looking very sad. :(


Yesterday I had a chance to check out the engine. The plug didn't look that bad. Could be a little more brown.


The piston had some discoloration, but it wasn't really burnt underneath. This is a good way to check to see if you are detonating and cooking the piston.


The piston did seize at the ring pin. The cylinder looks pretty good, and I should be able to clean it up with some muriatic acid. I didn't get a photo of the cylinder. Have to do that when I work on it!


Okay so how did I unravel the mystery? I recently put together a leak down test kit for my Derbi engines.





I decided to employ it on the Monza engine. I discovered three leaks. The first two were at the case seems just below the cylinder on the top and bottom of the cases. These didn't really surprise me all that much. But the next one did!




The third leak is actually a hole from the skirt area in the crank case. You can see light shining through the cases.



I knew the previous owner had gone crazy on the cases, but I didn't realize to what extent. He must have bored out all the way through, and then bodged it up with some JB weld epoxy. Eventually the epoxy failed.

I knew there was an issue with the cases because the previous owner had bored into the case screws. I replaced these with bolts, and to keep them from leaking I had to install them with sealant.



I'm really not sure what I'm going to do about it. I could bodge it up some more with JB weld. I could get the cases welled up, or I could just try to source some replacement cases.

Went and snapped a photo of the cylinder. It should be easy enough to clean up. These Gila kits are amazing. :P

Hi Jeff, yes it is very sad. But hopefully I can find some engine cases for it. :D

Ok, sure that this is possible.

Lo siento mucho, pero es una gripada de academia.

Por lo que puede ver en las imagenes, demasiado gas y poca gasolina, la mezcla es pobre.

Tambien creo que se han pasado mandrinando de los carteres, no te queda otra que la de soldar con aluminio en la zona y volver a mandrinar a la medida del cilindro, o conseguir unos carteres o un motor nuevo.

En mi opinion es un motor muy pequeño y demasiado antiguo para soportar tanta potencia.

Con el cilindro de 500 cc y un carburador de 18 mm, con encendido original te duraria toda la vida, alargando ostensiblemente la vida del motor no sufriendo averias.

Pero animo en su reparacion, son cosas que gustan ver, asi que no paren las fotos.

Menudo material os gastais en los USA.

Un saludo.


I'm sorry, but it is seized to the academy.

As you can see in the pictures, too little gas and gasoline, the mixture is poor.

I also think it's been mandrinando of crankcases, you have no other than aluminum welding in the area and re-boring of the cylinder to measure or achieve or a new engine crankcases.

In my opinion it is a very small and too old to withstand much power motor.

With the cylinder 500 cc and a 18mm carburetor with stock ignition it would last you a lifetime, significantly extending the life of the engine does not suffer breakdowns.

But I encourage you in your repair, are things like see, so do not stop photos.

I often materials you spend in the US.

A greeting.

Hi Perez,

Sorry for the English!

Yes the seize was due to not enough fuel. Which was caused by four air leaks. One at the head, two at the case joints, and the fourth being the hole in the cases.

Plus I had just installed a new ignition incorrectly. I had mis-read the marks. Totally my fault! Even with all of that the bike ran well enough that if I hadn't ridden it hard it probably would have been okay. So altogether combined fried the piston!

But it's okay I can get another piston, and I already have another kit. I need to do a little bit of work on the engine.  

This time though, I want to replace the cases. Yes I could have my friend weld them up, and if I can't find replacements then that's what I will do. But I want to replace them because the previous owner didn't do a good job of boring out the cases for the BBK. And I want to do it properly!

To me a stock bike is fine, but not what I want to ride. And I very much build my bikes to ride.    The Monza with the setup I have is one of the most fun bikes you can ride. Seriously, if you have a Monza get a Gila, an HPI, 24mm PWK, and a Jolly Moto. Why? Because the smile it will put on your face will last a lifetime.  

Yes this means that every once in a while I have to work on the bike. That's okay. I love working on the bikes (can't you tell?).  

Also this time I want to get one of the Rito performance cranks. I mean doesn't this look sexy?  


The crank in the bike isn't bad. We did some nice work on it, and added a Rito connecting rod. But it would be nice to have an actual performance crank. I also want to get the higher finger count clutch. The clutch on this engine is quite small, and asking it to take this much power is asking a lot. Replacing the clutch discs every couple of years is kind of a maintenance sort of thing.

But the transmission, and other bits can handle this amount of power. The Gila kit after all was developed specifically for this engine.  

For now though the Monza has to wait. I'm working on my Derbi Street bike. I just finished building up this engine, and I'm now going through the chassis.  

Madre del amor hermoso que cosas nos estas enseñando, acabo de hacerme pis . (no se si tiene traduccion).

Es igual, very very sexy.

Saludos.

Tora habla de que tuvo la culpa de que la moto gripase, ademas de no tener suficiente combustible, tenia varias fugas entre las juntas de los carteres y en la base del carter donde aloja el cilindro, (ver fotos ). Tambien achaca el gripaje al mal calado del encendido.

Que los carteres los va a reparar, tiene amistades como todo el mundo.

Le comente que esta moto no esta preparada para tanta potencia, y él me comenta que asi es divertidisima de conducir, que se lo pasa genial, ademas asi hace mucho de mecanico, cosa que le encanta.

Luego el cigüenal que se ve en la foto es para una derbi street que tiene, amen de todo lo demas que se ven en la fotos, en la cual esta trabajando.

Saludos.

Tora a question.

In the derby engine Rotax street is home?

It's like riding the Aprilia motorcycles or gilera.

If so, it is a very good motorcycle for fun.

A greeting.

Hi Perez,

The newer Gileras are Derbis. In 2006 the Aprilia RS50 became a Derbi with different plastics. Piagio bought up everyone, and made them the same thing. The older RS50 had an engine made by Minarelli called the AM6. It's a pretty decent engine, but I much prefer the Derbi engine. Although the AM6 has plenty of fans.  

Even Honda sells a bike with an AM6 in it! So it is quite popular. Many brands use that engine. But when Piagio bought Derbi they decided that they didn't need to buy an engine from Minarelli because they could just use the Derbi engine. I think this was a good thing for the Aprilia riders.  

In MotoGP the Derbi engineers (different ones) built the engine that became unbeatable. This is the Derbi that Marc Marquez rode. Can you imagine how much fun it would be to ride that bike?


I really like the Monza, and it is super fun to ride. But my all time favorite bike is my 2005 GPR. The 2000 GPR is a very close second. The RSV that I had was really nice. Probably the nicest bike I've ever owned. That one was sold. These days I have plenty of fun with the smaller two strokes. Although maybe someday I'll get an RC390. Maybe.

Anyway here's a photo of my 05 GPR before I took it apart. The reason it doesn't have plastics is because I was crashed by a car, and that broke the farings. This is the setup that did about 19HP on the dyno at the rear wheel. It was an animal. Almost scary to ride, but you do get use to it. The engine I just built for it (in the other photos) wont be quite as powerful. But the 19hp engine I never got running quite right, so I'm going to take it apart and figure out what's going on with it.    But I didn't want to wait so long, so I built up another engine to run in the bike until I figure out what's going on with the 19HP engine.  

My 2000 GPR, which sadly had to be taken apart because it has been run over ten times by bad drivers. This bike is super fun to ride, and easy too. The 05 requires more effort, but then it is higher strung.

As you can tell I really like the Derbi. I was hoping to go to Barcelona to see the Derbi factory. But Piagio closed it down. I still hope to go to Spain, buy a Derbi, and ride around Europe. Maybe I can do this next year. That would be Dreamy!

19cv!!!!

Hi Tora Tora.
Congratulations on these very cool motorcycle you have. They are very nice.
The preparation of Monza will be great.
Cheers.

That's right Jeff 19. I wish you could ride it. It's so much fun. It's like riding a bull. There's around 5 to 6 HP (very close to stock peak power) until 9K then it hits the pipe, and starts climbing until 13.5K rpm. But I keep blowing up cylinders. So I have to rethink that engine!

MC, thanks, but right now I really don't have any of them working.  

The Monza was also run over a bunch of times while parked, plus I just seized it. The Red bike was run over ten times, so I took it all apart, and will do another restoration after the Monza gets back on the road.

The last asshole that hit and ran, backed up over the sidewalk to hit both bikes slamming them into a wall.

The Track Bike is really close. Just needs some tuning, and a new intake manifold. I used a lot of the Red bikes parts for the track bike! And the 05 is still apart in the kitchen. But I hope to have some running bikes soon. Oh and there's also the Senda project. I've been collecting parts for the Senda for many many years.

It's really sad--and the SFPD wont do anything about it because they are "too busy." :(

Today was kind of a sad Monza day.

I decided to start back in on taking it apart, and today I had some time, and the weather was nice enough that I could work on the bike. But I did run out of light, so I'll have to go back to it later.

The good news is that this pushes it that much closer to coming back together. ;)

Oh I guess there is some good news to share. I've been riding the track bike. Put new reeds in it yesterday. And I picked up a 2004 Silver GPR. So far it is mostly stock, but I'm having a great time riding it around. Rest assured it will get turned into a fast bike soon enough. ;)

The title of this may be the puch monza reborn from its ashes, so I encourage sure the leaves better than before.

Material often you've caught, it is impressive.

This derby has to go, yes o yes.

A greeting.

Hi Perez! Thank you for the nice words. I will bring it back. It's just going to take a while this time. The Black GPR is the bike that's getting the current effort. It's sad though. We put so much effort into building these bikes only to have some oblivious person reck them in an instant. :(

I am looking to go to Europe soon. I plan to get a bike there (a Spanish one!), and ride around a bunch. Hopefully I can meet up with you and Jeff, and some other of my Spanish friends too. :)

Hi Rob

I have read your storry from your Cobra and i like the Bike . It´s nice to see that Puch Bikes are all over the world . I am from Austria and i also have some Puch Bikes and love to drive them around . Maybe when you need help or something tell me and i will help you .

Rene