almost ready to rev

happy hunting...

it's all been posted before, but here's some tips to help you search...

free mods are port matching the exhaust and intake. this should be done to every china motor before you even put it on the bike.

lapping the head and trimming the intake side of the piston skirt are two more things you can do for free.

basic bike upkeep is also free, and easily overlooked. keep your tires inflated, your wheel bearings greased and cones tightened properly. you'd be surprised at how much a dragging wheel or low tire pressure can slow you down.

cheap mods are upgrading the plug and wire. NGK B6HS plug and a 7mm copper core plug wire are the most popular choices, and are arguably the best. for hot florida summers, a B7HS plug is a good choice.

i love opti 2 oil at 100:1 mix. it's magic stuff that actually works and can keep your bike running strong and clean. there's a 100+ page thread on it that's pretty entertaining.

dumping the problematic CNS carb for a trouble-free NT is another good upgrade, and the NT is cheap. the NT "speed" carb is even better. not too many people have had success with making the CNS perform properly.

drilling some holes in the stock air cleaner box is free, or upgrading to a better flowing air cleaner is usually recommended, too.

a lot of people will tell you to get an expansion chamber, and claim it's the best bolt on upgrade you can do. i disagree. my fastest bikes use modified stock exhausts. you can gut the internals of the stock pipe, and keep the end cap. it'll be a little louder, but not as loud as an x chamber. one of my bikes has a supertrapp muffler and that's faster than any of the factory chambers i've used.

for hills, the sbp shift kit might be the way to go. i've never used one, so i can't give an opinion on it.

then there's aftermarket heads. my opinion is if your head works, don't bother. there's problems with the factory slant heads warping, so this might be an option. my street bikes have the older, stock, straight plug heads, and i don't have any problems with them.

once you get into mikuni or dellorto carbs, custom heads, shaving piston crowns, truing cranks, upgrading bearings, reed valves, and other costly, time consuming mods, you're getting into the territory of race bikes, and while this stuff may work, you'll find yourself working on your bike more than you're riding it...

good luck.

these things are a little bit here and there.
1 - first thing is setup ur carb when u change ur mix after breakin. so its running correctly.
2 - port and polishing the intake and exhaust ports. you can do this manually and use the china hardware, or there is options to buy on a few different sites.
http://motorbicycling.com/showthread.php?t=16646
3 - if u havnt already, get a better chain than the 410/415. personally i have the 41.
http://motorbicycling.com/showthread.php?t=32183
4- get rid of the stock tensioner.
http://www.google.com/cse?cx=partne...7&ss=2024j625344j11#gsc.tab=0&gsc.q=tensioner
5 - drill or cut the stock muffler, some ppl are against it. some ppl for it. others would just say to get a new muffler. there is threads around here for that aswell.

im sure that there is more, but thats whats on top of my head at the moment.

picklefish said:

yeah, terms like Lapping and Port Matching are foreign to me. Im def gonna take your advice though, I appreciate it. I also read a thread about timing adjustments, seems straight forward enough but Im not skilled enough yet to understand these things. I remember using a timing light growing up on my VW engine. Have you messed with the timing on yours?

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that type of timing is non-existant on these little 2stokes. the timing is inside the CDI unit, and can really only be modified by building a new one. but there is a thread around, for changing timing via the magneto magnet.

i wouldn't bother with the timing. i never do, and i never needed to. the performance gains are minimal, and people i know who've done it have never convinced me it actually works.

port matching simply means to make the holes match up. if you look at your intake manifold, there's a dime sized hole where it mates to the large rectangular hole on the engine. same with the exhaust.

you want to grind the intake manifold and the exhaust flange holes to match the ports on the engine. you can't usually get them exact because there's not enough material on the flanges, but get them as close as you can.

lapping the head means shaving off a few millimeters at the mounting surface for higher compression.

this is best done on a mill, but for us low-budget mechanics, a piece of wet sandpaper taped to a piece of glass works fine.

picklefish said:

mounting surface? lol, Im so green. Perhaps there is a small engine coloring book I could use. lol.

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the mounting surface he was refering to is where the gasket sits to join the to parts. heres a vid of guy lapping an MC head.
http://youtu.be/cQHdXcqAo-k

The 2 best parts I have tried have been the Puch hi compression head and the Jaguar cdi!! Also the SBP pipe and shift kit are great for a balance of hill climbing/acceleration and speed. Running the SBP pipe, and shift kit along with the head and cdi have made my bike a great all around performer!

Read about the Jag cdi here: http://www.jnmotorsbikes.com/Jaguar_CDI_p/jnm1195.htm

All the changes you make will effect the carb tuning so if you dont do the carb last you will have to at least check the carb tuning after other changes, especially the exhaust.

picklefish said:

mounting surface? lol, Im so green. Perhaps there is a small engine coloring book I could use. lol.

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These cheap china kits are a GREAT way to learn the care and feeding of a ring-dinger. The same principles apply to ANY piston port two stroke, from tiny rc engines, up to open class motocrossers.
My advice would be:
1: match the stock ports and trim the piston.
2: Gut the stock pipe for better flow or get a expansion chamber pipe.
3: High compression head (threads in here about several, including my choice, the puch70cc moped head)
4: modified cylinder with agressive port timing and reed block modification.
All these work to improve power, usually at the expense of reliability. #4 is really out of the realm of daily use rides once you get to this level.
The first three can be done easily on a budget if you shop around. There is enough info in this forum to help you decide what works for your needs.

picklefish said:

The first ive heard of trim the piston.....do tell?

Im gutting the stock pipe and doing the matching etc for sure.
the last two have to wait for finances to catch up. lol. Im just going up a steep incline, no intention to race the thing. lol. Although we have a nice park with a bmx style dirt track that it might be fun to race motorized bicycles on!
appreciate your advice! I love this Forums members!

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Some kits have the intake port partially blocked by the piston skirt when it's at top dead center.
Look down the intake while turning the motor and you will see the skirt blocking the port.
Trimming the skirt to match the port can help power and possibly improve vibration a bit due to better balance.

maniac57 said:

2: Gut the stock pipe for better flow or get a expansion chamber pipe.

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when u say "gut" it, do u mean all the baffles and everything?
i chopped the pipe and knocked a baffle or 2 out, but seems to be ok.