MOPED ARMY

Usually comes down to a few questions:

1. What do you want out of the finished bike, performance-wise

2. How mechanically skilled and/or dedicated to the project are you (one can make up for the other)

3. What's the budget

^Yes the kit shown above from Dos Cycles is a really excellent kit and reasonably priced. The Puch 70cc treats for the people Version 1 piston port kit I've also been having surprisingly good results with. You must run synthetic oil at 2% because all newer kits in general are poorly cast nowadays you need max protection especially during break in and you must time low (do not do what I did a year ago on a previous Maxi I used to own and time high because you will run too hot and seize quick) and above all run a temp gauge. Yes the temp gauge is $50 but it can save you and your new kit a lot of grief! Chamfer your ports and gap your ring to around .014" to .015"

If you just want a slightly better stock replacement cylinder the airsal 65 is perfect out of the box. Zero prep or case match, slap it on and go. Low to mid 40s with good acceleration. I am running a 14 bing with a proma GP and it's a nice quiet around town bike, I would let my 70 year old mom ride it any day of the week. Sips gas and keeps up just fine on an average group ride.

The cheap 70 piston port kits are a little bit pickier about tuning and setup, but paired with a bing and proma circuit/tecno estoril/bullet pipe they will give you a more dramatic kitted moped performance boost, and built right will put you into the 50s. I haven't built one in years so I have no advice on the specific flavors of China/Taiwan no name junk everyone is selling. Most are pretty similar once they are setup right but some take more screwing around.

Pretty much all I build anymore are polinis... They are in a class of their own. Hands down the best all around puch kit. They can be a 45 mph chill ripper or a 70 mph face melting blaster depending on how you set them up. A good beginner setup is the polini with a bing 15 and a tecno estoril, if you do a good job building it with no airleaks and tune it right it will go 50, get there fast, and run for years and years. As you get better at tuning you can keep upgrading with different carbs and pipes to make it whatever you want.

The dark horse is the tomos a35 kits, aka 'treats Reed' they are based on copies of the a35 alukit and they can be rock sold blasters, but you have to do a lot more messing around to make them work. By the time you set them up with reeds, intake, carb etc the price is about the same as the polini and they really need to be ported to run as well. The good news is they are nearly impossible to seize and will run pretty ok even with your tune way off, but you don't want to be that person with 55mph worth of parts going 35 running like shit.

Anything bigger is best left to a future build, not that you can't be successful building a big kit first time, but mistakes are a lot more expensive and there are more tricks to the setup that you will learn working your way up through the ranks

Ahh yeah what people are taking about is a bit worse than that, some of the kits, cylinders and Pistons come from different suppliers or different markets where they are made to fit slightly different bikes. When you put them on the 70s era u.s. market bike they don't line up and in severe cases the port timing can be off 2-3 mm. If the kit is something special, super cheap or blasty, it's worth making it work but for a first timer it can turn a 3 hour job into several weeks of custom machining or looking for specific parts.

Treatland, dos cycles, Denny, are all great, we are lucky to have such awesome vendors in the community.

It's best to think about it as a whole system, start with what you want it to do, and go from there. Since there are only so many parts, over the years people have kinda figured out what parts make a good system. If you put a huge pipe on a small kit it won't run right, so stick to something proven. Pipe and carb are just as important as the kit, sometimes more so.

No thanks! I don't like that bulgy look to it.

Part and parcel to 2 stroke exhausts dude

Just keep the stock exhaust. You can get into the low 40s with no expansion chamber. I built one the other day and it is so good, I almost refuse to put big pipes on people’s “stock” maxi’s. Unless you’re tryin to burn up clutches and beat your friends to the top of that hill it really is the best. I can’t stand loud, dragging pipes that get in the way anymore.

For the kit I pretty much always go for the airsal 44; it is very nice and torquey, and assuming you have a 1.5 or 2hp low torque maxi you can use the stock head, and it doesn’t feel anemic with the original carb. For preparing the cylinder there is very little to do with this one, I usually just plug the decompression hole with an m6 set screw and run a bit of sandpaper around the shape edges of the piston, but it does have plenty of potential if you want to get crazy porting. My only complaint is cylinder plating is very thin so be careful if you’re doing any filing or a pit a rotary tool to the ports that you don’t chip it.

@daniel, my proma GP will fight u!

Yeah I really like this little kit, took me awhile to get the jetting on the bing right since it is jetted more like stock cylinder. Normally you're trying to get the bing as lean as you can in the mid/low with a huge main, I'm at a 74 main and could probably do a 72. I was actually thinking I might try an SHA since it's such a flat fuel delivery. It still feels a bit soft in the lower mid right where the clutch grabs but going up a click on the needle wrecks my nice low putt putt idle and doesn't really help.

I could probably put a bunch more timing back in it too, can't even remember what it's time at, set it conservative for break in and never went back to bump it up.

Graham, .. Starting to work more with Puchs. I have a reliable Airsal 65 installed on a Magnum XK, 15 bing, Techno Estoril and have a good stock Magnum E50 I'll be building for next year. What else can you recommend for the Pollini build you described as far as porting, crank, clutch, bell, gears, head, intake, etc? 50-60% of our riding is open road at 35-55 mph with the rest being stop-n-go in the city. My Malossi LC Hobbits can rip in all those conditions NP but the 65 XK is a challenge for an E50 novice like me when trying to balance good take off and hill climbing with higher end cruising. Durability is a priority as many of our weekly rides cover 40-60 miles+.

Steve, the Big thing with the polini is the pipe, the kit almost is secondary to the pipe, that's why I like polini so much now that I feel like I better understand them, you can make them do almost anything with the right pipe.

I would start the build around a crank pipe or a modified tecno estoril, or an MLM but really fuck all that and just get your crank pipe on order. Next ya gotta keep it cool, I (obviously) like the mopedfactory head that I sell though dos cycles, or you can buy direct from me (same price, dos just probably faster shipping) you will also need a retarding CDI. You can set the timing low with points like ken says but then your midrange sucks. I am running the parmakit box on an A55 stator but there is a really good thread on this just posted a couple weeks ago. I would say hpi mini rotor or parmakit box are the most well documented, but anything that retards reliably.

I'm running a modified 2 shoe clutch, but I'm finally starting to hit the limit on that, my bike is close to 60 now with the 18x40 and the clutch is hating life riding dubs. I am gonna try the pavo shoes for next season since I've seen Lee's bike out a few times and it fuckin rips.

I haven't tried a 4 petal with the bigger carb yet on the crankpipe but Ryan's and Nick's are fast AF. I think it might be necessary to truly break 60 but I like the simplicity and tuneability of the phbg 19 with the 2 petal. I have tried all the reeds and like the Athena rubber coated with a spacer under it to clear the casting. I think anything from a SHA to a TM24 will work good on a polini, but the phbg is just what I had laying around. I have a polini CP I've been meaning to throw on there, maybe next season.