1978 Puch/Kromag Free Spirit build

Well, kind of a build. Mostly just keeping track of me turning this 1hp hog into a quick and reliable daily putter. I figured I'd make a thread for it.

Here's a picture right when I bought it. It's in good shape and runs great, the chrome is a bit pitted (big deal) and you can't see but the entire underside is caked in dried mud. Someone had some fun on it, haha. Tires are the original ones.

1978 Kromag Free Spirit.jpg

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Okay, so today I cleaned off as much dirt as I could from the engine. I found that it was the restricted 1hp model, so I dremeled the plug out of the intake manifold, which helped it run a lot better. It was originally 4 stroking at WOT, removing the restrictor helped that a lot. Stock top speed was 20-21mph, due to the restriction and a 12T front sprocket. I also removed the head gasket for a touch more compression. Today I got it up to 28mph on a slight downhill, woooooooo! I'm trying not to ride it until I get new tires and can upjet the carb, it's just so damn fun to ride. I have a slight air leak somewhere, so I need to look into that. Tomorrow I'll probably pull the head off and make sure the surface is perfectly clean and retorque it. I'm almost 100% sure the leak is there.

My goals for this are to keep it nice and reliable with good gas mileage, but more powerful so that it can cruise at 35mph on my way to work in the mornings. A bit more style would be nice also. I just put in a big order last night from treatland:

new tires (michelin gazelle, 2.25 front 2.75 rear) and tubes

K&N style air filter

jammy pipe

new chain, petcock, rear view mirror, and a bunch of jets

larger front sprocket

new handlebars

I'm pretty confident that these mods and better gearing can get me up to at least 35 on the flats. Hopefully 40. I'm looking forward to it. As of now I have no plans on increasing the displacement any, I just want to keep the mods mild. I've caught the bug now though, so if I manage to "accidentally" find another moped around here for cheap I'll probably get it and build up a 99cc monster.

Parts should be here by about Friday, so next weekend I'll be putting this stuff on and learning about tuning first hand! Oh, and my new helmet should be here soon, too. Best to keep brains inside the skull.

Re: 1978 Puch/Kromag Free Spirit build

Dirty30 Dillon /

If you just removed the head gasket without flattening the cylinder and head on something dead flat, you definitely have a leak.

I'd just run a head gasket if you're looking for a mild dd.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

I had read about people just running no gasket to get higher compression. I thought it sounded fishy but they all seemed happy with it. Never read anything about flattening stuff. I guess I should have thought about that one first, haha. Whoops! I don't have anything dead flat around here to use, so I guess I'll go back to running a head gasket. All good fun and learning.

Re: 1978 Puch/Kromag Free Spirit build

The gazelle m62s are really heavy tires and you can almost run them with no air in them, but they are good tires I have them...They slowed me down just a little...You better be good at putting them on without puncturing the tubes their a freakin bear to get on, be prepaired for a fight.....

Re: 1978 Puch/Kromag Free Spirit build

My FS is a bone stock 2hp model and, with the exception of a 16 tooth front sprocket, tops out in the mid 30's at the expense of low end power but that's what pedals are for.

I hate to say it, because your bike looks minty & unmolested, but if you're going to make a fast bike, you've got one of the best platforms to do so already.

Super strong tube frame construction with a wide, durable swing arm that can take up to 2.75in tires, lots of room around the carb area, the wide pedal clearance gives you so many options with that bike. It's an E50 Puch, so performance mods are nearly endless, easy and inexpensive. The engine is stupid-simple and very robust.

Detachable tank is a great feature 'cause kitted bike are thirsty so it can easily be replaced with a larger capacity one. Or do a top tank conversion if you're conventional.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Bobby - I read a lot about those tires and they seem to be really good, albeit a bit heavy like you said. Them being run flat is an extra plus. Thanks for the warning about putting them on, too!

Chris - I'm going to make it fast but I'm not going to mod it too too much. It's in nice shape and I don't want to hack it up. If yours will hit mid 30s then I'm hoping with better gearing, slightly taller rear tire, and some more power I can hit 40+. I guess I'll find out. Glad to know I got a good one also. I'm really happy with this bike so far. A top tank conversion would look great and I'd love that, but I don't know how to weld and I think this bike is too nice for that.

Now that I've caught the bug, after I get a few mods on this one I'm hoping I'll luck out and find an old beater for cheap that I can tear apart and build from the ground up. I'd definitely do a top tank conversion on an old beater. (edited)

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Looky what came in the mail today. Hi comp head and a new head gasket. Looking forward to slapping it on.

(edited)

hi comp head.jpg

Re: 1978 Puch/Kromag Free Spirit build

I like this thread. Dude get an exhaust.

Re: 1978 Puch/Kromag Free Spirit build

Probably Fred /

Armon Nicholson Wrote:

-------------------------------------------------------

> Looky what came in the mail today. Hi comp head

> and a new head gasket. Looking forward to

> slapping it on.

>

> https://www.mopedarmy.com/forums/file.php/1/117291/

> hi_comp_head.jpg

Don't look very high compression to me

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

It's this one:

https://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-comp-head-50cc-old.htm

I'll install it tomorrow after work and see what kind of changes it makes.

Nick - exhaust and a bunch of other goodies are in the mail. I was hoping they'd be here in time for the weekend but it looks like they'll get here Monday. (edited)

Re: 1978 Puch/Kromag Free Spirit build

Probably Fred /

Like I said it's not hi compression

Only like 1mm smaller like if you sanded your stock old style head down 1mm

https://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-comp-head-50cc.htm

Now this is high compression ^

Almost too much compression. I actually mod the hi hi head for a little less compression .

You just wasted 23.00

30.00 Hi hi head for the win

Re: 1978 Puch/Kromag Free Spirit build

What pipe?

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

It's higher compression than my stock head and I learned something in the process. So I definitely don't feel like I wasted any money. To be frank, I really don't give two shits if you feel like I wasted any money. Now, back to building my moped.

Re: 1978 Puch/Kromag Free Spirit build

If you want your bike fast without increasing the displacement you're gonna be trading your take off power for that fastness by means of gearing. That means you're gonna want to rely on pedaling from a stop. Definitely get a tiny freewheel, like a 16 or 17 tooth. They're only like 8 bucks. That way you can trade all your takeoff power for top end speed and still be able to take off halfway decent. Trust me, you'll love it!

The jammy pipe is quite a bit better than the stock pipe. It sounds wayyy better and will give you much better bottom end but for a few bucks more I would've gone with either the Tecno Boss, or even better, the Tecno Estoril. I'm not really sure how ideal the Estoril is on a stock cylinder though.

Good luck! I remember when I caught the bug!

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Thanks! I just have to change the gearing, right now I was able to hit 28 downhill and the engine sounded like it was about to explode. That 12 tooth front sprocket is waayyyy too small. And if I end up overgearing it, then I'll just use that as an excuse to build more power, haha.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Well, I got all my stuff in the mail. The new handlebars went on perfectly and they're nice and comfy and it's great to finally have a rear view mirror. The pipe went on well but the mounting slots at the rear don't line up with the bolt on my frame, so I'm going to have to figure out a secure way to mount it. And I put the tires on and they went on great... but I accidentally put a hole in the rear inner tube, god damnit. So I had to order some new tubes. I went ahead and ordered extras, and got a nice tire iron, which I feel would make it much easier than a flathead screwdriver. Also put a 17t front sprocket on.

Also nice to know, there's plenty of room for the 2.75" wide tire in the back. In fact, if I pulled the wheel back a tad, far back in the mounting slots, there may even be enough room for a 3" wide wheel.

So now I'm just waiting on tubes and a chain tool, and once I get everything on I'll post some pictures. It looks a lot better with new handlebars and tires, that's for certain. I can't wait to get the right jet in there and see how it performs.

Re: 1978 Puch/Kromag Free Spirit build

You could go get a patch kit at a bicycle shop/walmart/auto zone for that tube. If you wanted new tubes in when they show up you could still go that route, but patching tubes can be a bit of an art and is good to practice.

That and patch kits are dirt cheap, and handy to keep in your tool-kit if you're far from home at all.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Well, after putting on and taking off the rear tire a bunch of times I ended up damaging the bead, so I had to order a new tire. Went ahead and got some new tubes also while I was at it. I'll let a local tire shop put the new tire on. Those Gazelles are tough.

I went ahead and put on my pipe and new air filter and upjetted my carb. My stock jet was a 52 so I tossed a 64 in there, based on a spreadsheet I read of similar mods. Once I get my new tire on so I can ride it, I'll tune it and get the right jet in there. Then I'll focus on everything else I need to get it tuned and running right. Also put an LED tail light bulb in there, it's a big improvement. Pics to come once I get the new rear tire.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Okay, some updates. Installed:

F/R tires

cafe handlebars

new chain

pipe

air filter

hi comp head

upjetted

side gapped spark plug

First a picture:

(edited)

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

And now the issue. Stock it came with a 52 jet. I read through a spreadsheet of E50s with Bing 14s and similar mods and decided to start with a 64. So I put a 64 in, let it warm up and rode it around some. It ran fine for probably 2 miles, then suddenly lost all power and died. I thought it might have been soft seizing, so I let it cool down for a bit and started it back up. After 20 seconds it did it again, so I pedaled home. I read that seizing is usually because it's running lean, so just in case it was seizing and not just cutting out, I up jetted and ran it again, twice. I ended up with a 74 in there, which I'm sure is too big, but it still cuts out. Even if I let it idle for a while, it'll just cut out after about 2 minutes. The engine is not getting too hot, so now I don't think it's seizing, it's just dying for some reason. Can anyone help me out on this?

And on a more positive note, the short time I got to enjoy it, it was pretty nice. There's some extra friction in the rear wheel now, almost like the rear brake is slightly dragging, and that's killing my top end, but even still it can hit 30-33 on a flat without any problem, and I hit 38 on a slight downhill. I still have plenty of RPM left. Once I get it tuned right and figure out what's dragging in the rear end, I'm sure I'll pick up a few more mph. For the record the tire isn't rubbing anything and the chain isn't too tight. I thought it may be the rear brake, but I loosened the cable until it wouldn't do anything and the rear end still acted the same way, so I don't think that's it.

Re: 1978 Puch/Kromag Free Spirit build

Hey so idk if you noticed, but there is a 9mm intake restrictor in the the intake behind the carb. it is plastic and easily comes out with a little dremeling. that "should" get you to 30, but i dunno how well a jammy performs. with a tecno circuit im seeing almost 40 on the flat with some porting and a 15t sprocket

Re: 1978 Puch/Kromag Free Spirit build

Dirty30 Dillon /

Super nice, stockish build. I like this.

Also, your cutting out sounds an awful lot like a bad condenser issue, which, when bad, will fail when it reaches a certain temperature.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Daniel - I removed the intake restrictor

Dillon - that sounds like it could be it. I'll check into it today, as well as clean out my entire fuel system and carb.

Re: 1978 Puch/Kromag Free Spirit build

those are cool bikes. trying to put one together right now, but also trying to spend exactly no money on it, so it will surely be less rad.

Re: 1978 Puch/Kromag Free Spirit build

andrew simpson /

looking really nice

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Well I cleaned out my gas tank, and it was full of old crud and rust sludge and whatnot. I cleaned it the best I could and installed a new petcock and cleaned out my carb, and rejected it back to a 66 (which I think is a more realistic place to start) and it runs great now, at least in terms of that. It's not cutting out or anything. I still have some friction/drag coming from either the rear wheel or the front sprocket area (I keep wanting to call it the transmission, but I'm not sure that's exactly correct). Can anyone think of any reasons why it would suddenly turn slightly less freely?

Oh, and I'm thinking in the near future I may convert it to kick start and get rid of the pedals. It has a kinda vintage motorcycle look with the new handlebars and I'd like to continue that theme. (edited)

Re: 1978 Puch/Kromag Free Spirit build

Dirty30 Dillon /

Rear brake drag sounds more likely than transmission drag, but checking/changing the fluid is not a bad idea.

Don't lose the pedals! They're what make them awesome, especially when it's so mint.

I just picked up a Free Spirit frame/swingarm I plan on build a super light bike out of.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Very nice. From what I have read, the free spirit frame is a nice strong one. And I know for a fact you can easily fit a 2.75" michelin gazelle in the rear end.

I'm not sure how to check the rear brake for drag. I just remember that removing the cable is a huge pain in the ass. I tried loosening the brake all the way and it doesn't change the friction issue. It really seems to be coming from the front sprocket. I'm no expert though, and I'll try to mess with the rear brake some.

Re: 1978 Puch/Kromag Free Spirit build

Armon Nicholson /

Well the rear brake is free and not dragging, the rear bearings aren't being squished by the mounting bolts, and the rear wheel turns freely if the drive chain is removed. With the drive chain on however, there's a lot of drag and it doesn't turn freely. The chain itself is new, well oiled, and flexible, so it's not that. The front sprocket is brand new, so I'm not sure if that may be somehow contributing to it. My guess is that it's something in the transmission. So now I need to learn how to change transmission fluid. I'll do that after the weekend, since I'm heading up to Boston tomorrow.

Even still, I just took it down the road and it 40 on a downhill. Once I get this issue sorted out I know it'll go faster, but 40 on a moped is pretty damn fun.

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