Honda PA Cylinder summary

This is a summary of Honda PA cylinders.

I know it's not much (Not nearly as complete as the Puch summary) but it's a start.

You can make this better by adding your own experiences, adding timings, port shapes etc. Look at the Puch wiki and be inspired.

SPACING NOTE:

Many of the hobbit cylinders require multiple base gaskets and/or a base spacer. The spacing is off so that the head hits at TDC or the piston covers part of the exhaust still at BDC. This is most notably true of the Athena but other kits have the same problem. Spacers can be purchased premade from the main online retailers. There are 3 theories of why this is so common among the hobbit kits:

• 1) the PA501 and PA50M (Slow versions) have a tab in the case to prevent installing kits. the offset may have been intended along with a spacer to give clearance for the skirt and the restricting lip (see Honda PA Model Differences).
• 2) Many kits are made in Asia to save money, and often the shops that cast the cylinders and the shops that make the pistons are separate. In later runs and reproductions, the supplier of the pistons may change. In doing so the brand may only match the bore and wrist pin of the desired cylinder. It's possible, especially given that mismatched pistons are known to occur with other clone kits, that the pistons are a different height which creates the observed offset. This also may explain why there's a roughly consistent amount of offset if there are 2 general piston heights for the 65cc 46mm bore w/ 10mm wristpin.
• 3) Many of the kits, especially reproduction ones are made with lower tolerance. In order to make sure that the head and base are exactly parallel, the manufacturers mill the base. Some may require more milling and thus need additional base spacers to make up for the milled material. On some kits this is evident as the "49cc" (or "70cc") casting on the side of the cylinder may be halfway or more milled away even on a good new kit.

50cc Stock Honda

By far the most reliable cylinder. But it's also by far the slowest. With good porting and other mods it can be made quite fast.

Cast-iron

50cc Italkit

Fast 50cc with bigger ports than stock cylinder, 40mm cast iron. Best stock replacement.

K-star 50cc

Good cast-iron cylinder. Out-performs the stock Honda cylinder, but just slightly.

60cc K-star

Cast-iron cylinder with slightly larger bore.

60cc Stocko shocko/77 Cast Iron

44mm cast iron kit. Presumably recast from Chinese clones of the Hobbit such as Jailing and Dayang which had a 60cc stock version. Same as the 60cc 77 crate motor cylinders. Basically overbored stock cylinder. Minor performance gains over stock, if any. Requires base spacing. Typically requires additional base spacing - the amount may vary by each kit; the cylinder is aligned by milling the base and some take more or less material off to hit tolerance, but as a result the height is affected and some require many or no additional spacing on the base. May be worthwhile for stock replacement, but 50cc italkit is better and easier.

60cc Autisa

60cc 44mm Simple Cast Iron sleeve in an Aluminum body. Decent porting, not many reviews. Appears to be a better stock replacement option than the shocko, but far from a racey kit.

65cc DR

Cast-iron 65cc kit. Pretty good price/quality ratio. Torque cylinder. Renowned for being simple fast and reliable, the "best bang for the buck". Perhaps not as fast as some others, it's still very competitive and unparalleled in simplicity, reliability and cost.

65cc Fast Arrow / Wizard / 77 Alu kit

Fast arrow, now out of production has been revived by 1977mopeds as the "77 Alu kit" and Treatland as the "wizard" kit. Usually requires additional base spacer or extra gaskets. Higher RPM porting, loud, notoriously more sensitive to tuning.

65cc Polini Air cooled

Cast-iron 65cc cylinder kit. Little torque but high top speed. Do not expect the same high performance as puch polini, this is a more mild kit, but good among the 65cc hobbit options.

65cc Malossi

Cast-iron 65cc cylinder kit. Best AC cast-iron cylinder available. Good torque and good top speed.

65cc Metrakit

65cc kit. Little known.

65cc Zeta / Parmakit

Formerly Zeta with hard chrome wall.

Now Parmakit, cast iron with nicasil wall. 7 port, good performance

65cc BiTurbo

Aluminium cylinder with good performance for it's price. Pulls well and has decent top-speed.

65cc Proma

No picture

Very rare cylinder.

65cc Polini Liquid Cooled

Cast-iron watercooled cylinder.

68cc Malossi Liquid Cooled

Aluminium watercooled cylinder.

70cc Metrakit

This is a clone of the Derbi Metrakit, adapted to the hobbit. 47mm and 6 transfers, 2 auxiliary exhaust ports, and a nice large exhaust port. Uses Derbi head as well, offers better cooling. May require base spacing. Requires boring the case to fit the larger skirt. Much faster but more effort than the smaller kits.

73cc Athena

By far the best cylinder available for the Honda PA. Aluminium with nicasyl wall, 7 ports. 47.6mm it's largest of the hobbit kits. Requires additional base spacing of up to 3mm. Requires some work to line up, known for running hot.

Translated by SchijnHeilig

Original from Camino-tuning.be