Jawa Performance (not an oxymoron)

Anyone have any experience with these kits? I contacted them and asked about shipping to USA. Just wondering if the gains are worth the effort. About $253 shipped. I'm intrigued but thinking there is another way.

https://www.jackmotors.pl/old-timer/cylinder-jawa-50-45mm-70-4-racing-jmp?from=listing&campaign-id=19

Re: Jawa Performance (not an oxymoron)

Another option is running a Moby cylinder. You have to relocate the cylinder studs, have some material added to the transfer area of the Moby cylinder to match the transfers, and space the cylinder properly. We did this for our last raffle bike and the thing was a blast with the 70cc Moby Airsal kit.

Re: Jawa Performance (not an oxymoron)

100$ for shipping a cilinder seems a bit steep.

Re: Jawa Performance (not an oxymoron)

I'll research that Moby cylinder Option. I'd rather not do case mods to that extent though. Yes the shipping is outrageous. If nobody has any good input on these I'll pass.

If I could get this shipped as quickly and as relatively inexpensively as things from The Jawa Shop I'd jump on one of these.

Re: Jawa Performance (not an oxymoron)

> Frank Bailey (MOPITT) Wrote:

> -------------------------------------------------------

> I'll research that Moby cylinder Option. I'd rather not do case mods to

> that extent though. Yes the shipping is outrageous. If nobody has any

> good input on these I'll pass.

>

> If I could get this shipped as quickly and as relatively inexpensively

> as things from The Jawa Shop I'd jump on one of these.

Maybe see if the Jawa Shop would pick one up and ship it ? Might save you a little .

Re: Jawa Performance (not an oxymoron)

Good idea PD. Just emailed them as well as asking Jack Motors for better shipping options. We'll see...

Re: Jawa Performance (not an oxymoron)

Shipping things to the states under 5kg is about 40$ here, i doubt it would be much more expensive in Poland.(edited)

Re: Jawa Performance (not an oxymoron)

eBay has 10x overbore sized jawa pistons for around $50 shipped, iirc ... Dutchman Racing will do an overbore/hone/chamfer for $100 but there might be someone cheaper .... youd end up with a psuedo 60 kit. if you gave them a port map you wanted applied they probably do it for a few extra bucks before the chamfer.

Re: Jawa Performance (not an oxymoron)

Good option Monti. Can't find those pistons on eBay. As they say though, there's no replacement for displacement.

Re: Jawa Performance (not an oxymoron)

250 seems totally worth it, looks like a ripper. If I was trying to make a fast jawa I'd go this route no doubt.

Re: Jawa Performance (not an oxymoron)

Eric Davenport /

I've got 2 12x over (3mm over) jawa piston kits. I'd let one go cheap. Also they are really easy to port if you have a press

Re: Jawa Performance (not an oxymoron)

Look how inexpensive pistons are at The Jawa Shop. https://www.jawashop.com/piston-set-39-00-42-00mm-pin-14mm_z313/

Re: Jawa Performance (not an oxymoron)

Overpriced Parts /

Damn! I wish they had these options 20 some years ago when I had a supreme

Re: Jawa Performance (not an oxymoron)

how fast are you looking to go? most of the kitted jawas still are in the 39 to 40 mm range but just have other things tweaked. and some still go slightly over 40mph

Re: Jawa Performance (not an oxymoron)

I have two Jawas. One and two speeds. Both go over 33MPH, over 35 on a good day. I'm looking for a little more pickup on the one speed as well as better hill climbing. The whole thing is just an ongoing experiment. Both are fun right now, because they're Jawas.

Re: Jawa Performance (not an oxymoron)

This cylinder kit by Jack Motors is only for 3-speed Jawa 50 (Typ 05 Poneer, 20, 21, 23 Mustang) and will not fit Babetta or other Jawa vehicles.

But it's interesting, so I will try it on my 23-type engine.

Re: Jawa Performance (not an oxymoron)

> Max Ginsburg Wrote:

> -------------------------------------------------------

> This cylinder kit by Jack Motors is only for 3-speed Jawa 50 (Typ 05

> Poneer, 20, 21, 23 Mustang) and will not fit Babetta or other Jawa

> vehicles.

>

> But it's interesting, so I will try it on my 23-type engine.

Good to know. I thought the Jawa 50 and the Jawa 50 type 210 Babetta were the same thing. Oh well back to over boring and porting ideas

Re: Jawa Performance (not an oxymoron)

doesn't look particularly different, stroke different? or mounting or what? I'd be curious how far off it is.

I am a little weary of the moby route - how's that bike held up?

I ran a 103 kit on a BETA once and the vertical engine'd cylinder on a horizontal engine made for ultra shitty cooling and rapid overheating. I've seen people just drill a bunch holes through the fins and maybe that works?

Re: Jawa Performance (not an oxymoron)

Yes, stroke and mounting are different.

And this is one of those 3-speed Jawas.

khUb6aednfc.jpg

Re: Jawa Performance (not an oxymoron)

oh Iknow those bikes for damn sure, theyre topping my wishlist of weird old whips. that and the simson schwalbe's. love that era east euro scooters

Re: Jawa Performance (not an oxymoron)

Those Simsons and Schwalbes were really strong rivals to Jawa.

Now in Germany there is a lot of Simsons but old 3-speed Jawas are pretty rare.

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