puch maxi tuning,anyone done it.

[Albert 888]

ok Im picking up a 1985 unmolested puch maxi 50cc two speed automatic kick start and solid rear end.

Im going to ride it to work and back and see how it goes, then the plan is to modify it,

70cc full kit 149 euros.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Das Produkt ist leider nicht vorrätig.

 

anyone any tips etc.

its a project and a bit of fun

Looking for a PSR set 70cc cylinder NM + exhaust for Puch.url

Edited November 13, 2017 by Albert 888

[Jaymo]

Aaah man, I remeber 1980 and my mate David Turner having one- was so jealous but rode the hell out of it when I could.

Do you have any pics so I can reminisce?  Bit small for riding to work isn’t it?

Just checked, sorry it was the Puch Magnum X

Edited November 13, 2017 by Jaymo

[Albert 888]

second class traveling is better than first class walking, Im 6.1 also. as said a bit of fun to keep me busy. will do my best to upload some ,its a lot easier with the new layout of the site now.

[Wharf Rat]

If you want to play with the standard 'bike.'  Raise the exhaust port 1mm, widen it so only far that the rings don't distort or catch and polish the port to death.  Don't do the inlet as you need some swirl.  Advance the ignition a gnats nadgers and see what she does.

That K&N style filter in the pic will raise top speed but ruin acceleration, better to cut a larger hole in the airbox intake.

Do all that and it may crack 35mph...

[Albert 888]

I will give it a go, basically open the exhaust port 1mm higher. Then advance the ignition to suit. 

Think eventually I'm going bigger with everything hence the 70cc kit, bigger carb etc.

[oowee]

Cool project and a great way to get to work, if it's not too far 

[Dunkield]

Look at what Stan Stephen does to two strokes in Classic Motorcycle Mechanics mag. I have never done this but it sounds like Wharf Rat is on the money.

It can done, I went to college with a lad who tuned his to the limit and would scream past us lot on our fizzies once he got it going of course.

You can buy engine kits (to fit pushbikes of all things) from China for peanuts so that may be a more economical route?

Keep us posted I love stuff like this

 

[Fen tiger]

Can not say i have ever modified a small two stroke, but plenty of bigger ones.

This book is as good a source of two stroke tuning info as you could ever need you might be able to gain from it.

http://www.amrca.com/tech/tuners.pdf

[Albert 888]

Picked up the puch this morning, so I have started removing bits ie rear box and rack,luggage bars. 

I had some stainless nuts, bolts and washers so we're I can I have replaced. 

Found a sheard 5mm bolt,good job it was brass drilled and retapped the hole.

Removed the fuel, it stunk must have gone past its best,

Covered the engine frame etc in degreaser and jetwashed. 

Took it for a test run it flooded and had to push it home. Now sorted.

I have sent an email to the company who supplies the 70cc kit,to see what is the best way forward, I'm thinking complete engine rebuild,new crank bearings and seals etc.

 

 

 

[Rimfireboy]

Saw lots of youths with modded ones in France. Not seen any over here though. Would be good to see some pics when it’s done. Great stufff Albert.

[Hendrix's rifle]

You can get small 2 strokes to go like billyoh if you want. I had a 1986 dt50, high comp piston, porting, polishing, custom exhaust system, jetted carb after porting and it was awesome. Until 6 miles later it over heated new water pump and bigger rads sorted it out marginally. Wanted a fan on it but it ran a 6v system and I got rid of it not long after. As dunkield says Stan Stephens is a wizard with 2 strokes, my old man had an rd350lc with a Stan Stephens engine in it, was a laugh until it needed rings every other week keep us updated with it and enjoy yourself 

[Albert 888]

Today I completely stripped the carb down,it was nasty inside, cleaned out the main jet,fuel bowl,fuel inlet,polished the needle up,gaskets a bit tired but had to do my best with them.

Pulled out the baffles and cleaned,found baffle tube missing, put back together as was.

Dropped and changed the atf fluid,hardly any in but only take around 200ml.

Removed and cleaned up the throttle assembly, it's still only working 75%. Looking at fitting a domino fast action one but will have to make cables to suit.

Whent on a 3 mile test ride,will do 30mph on the flat,close to 35 downhill, and 20mph uphill.

It has no torque at all but everything works. 

Im still pondering over wich way to go with it,regarding 70cc kit,exhaust, carb,disc brakes,conventional forks.

Will try again with photos but it still hit and miss,I'm better with the spanners than I am on the computer or phone. 

[Albert 888]

[Albert 888]

I want it to look something similar to the one above,I have made a template cross bar out of plastic pipe, ready to make a steel one, don't know if i should use round or box yet.

3 minutes ago, Albert 888 said:

I want it to look something similar to the one above,I have made a template cross bar out of plastic pipe, ready to make a steel one, don't know if i should use round or box yet.

Bought this seat and brake ready to fab up when it arrives. 

[Albert 888]

OK,just ordered a high torque 70cc kit,barrel,head,piston,dellortro copy carb and jets, 45 degree high flow air filter,full racing crank,new bearings seals and gaskets for a full rebuild, jamarcol exhaust, flywheel remover,accelerator cable and a piston stop for £254 delivered from the Netherlands. With this kit I get all the instructions on what how and how much to remove from the engine to optimise what I want, I'm after a torquey quick motor not speed.

Edited November 16, 2017 by Albert 888

[Dunkield]

That should be basis for a 'sweet scoot' as they seem to say, now make sure you keep the updates and pictures coming 

[Albert 888]

OK bits arrived today,I test fit and ran the puch with new exhaust, it ran well once warm.

I have now remove kick-start cover,clutch which I was amazed to find a 3 shoe racing on inside,I used my homemade puller to get it off.

I removed the dynamo with a bought remover.

Then proceeded to strip the entire engine,not much of it from the bike and into bits.

Now cleaned ready to match mark the cases to the barrel, but I have found out I'm not going to have enough sealing face between the case and the barrel, so hopefully I can get the alloy case's built up with weld ready to file flush, enabling enough gasket contact area to seal the barrel to the case's. 

After that I'm ready to fit new bearings, seals etc to the new racing crank.

Hopefully see pictures below. 

[Albert 888]

[Albert 888]

[Albert 888]

I'm better at doing engines than uploading photos sorry.

 

 

[matgriff]

That clutch looks like a standard centrifugal clutch ?

With all that ££££ you've spent on the engine rebuild, don't scrimp on 2 stroke oil when you get it up and running, use a good quality fully synthetic to protect your investment :-)

 

[Hendrix's rifle]

Ahhh the simplicity of an old stroker, don't see that any more!

[Albert 888]

Top one gasket cut the the cylinder ports,bottom had to get weld built up then filed flat to get a better seal face for the bore. The bottom one I also ported it to the gasket, roughly 45degrees.

Edited November 21, 2017 by Albert 888

[Albert 888]

Now fully built up, inlet for carb had to be modified to get the carb sitting flatter,just clutch freeplay to sort but I need a thinner thrust washer,may try grinding it thinner,it hardened. 

All new bearing and seals fit,dmp 2.0 stuffed racing crank.

[Albert 888]

10 hours ago, matgriff said:

That clutch looks like a standard centrifugal clutch ?

With all that ££££ you've spent on the engine rebuild, don't scrimp on 2 stroke oil when you get it up and running, use a good quality fully synthetic to protect your investment :-)

 

I thought the 3 shoe was uprated and the 2 shoe was normal,may have got mixed up. Got a few tub of good stuff,going to run it 40:1 mix for a bit,used 70:1 in my trials bike.