Bore Kits and Racing Pipes

[Bennett]

So, I was told to get these by JD, so answer these for the newbie....

What is a Bore Kit?

What is a Racing Pipe?

What is the legality involved? :S

8-) thanks

[Cemorah]

In short I would not bother:-

But you asked so here goes:

Typically a "bore kit" or big bore kit is an over size piston & barrel taking your 50 to 65 -70cc. If you are under 17 you can only ride a 50cc so it wold be illegal to use on the road also you would not be insured. If you are over 17 then you can ride upto 125cc so it would be legal if you can get insurance for a modified bike - check this very carefully with your insurance company and check out how much extra the premiums are.

A two stroke engine uses the shape of the exhaust to to create pulses of pressure near the exhust port to help with scavenging and "port timing" useful when the engine has a large hole in it for 40% of the pistons stroke - the effect of a "racing pipe" is to tune this more accurately at high revs-this is a highly skilled art and fitting an aftermarket pipe may require re jetting the carb to suit. Have a look around at forums my experience tells me get all this wrong and your engine will run lean and hot somewhere in the rev range and melt a piston or worse. also how much extra oil will the larger piston surface require? you will need to reset your oil pump but to what is anyones guess

NB you will also suffer from the engine now 40% bigger drawing air through the same size carb will you be looking to change this for airflow gain? If so you might want to consider uprating the reed valve to give more area.

In a larger carb what jets will you need?

WHERE DO YOU WANT TO STOP AND HOW MUCH MONEY ARE YOU GOING TO THROW AT IT?

On a 50cc machine I feel the gain in performance would be limited. If the pipe works as it should you will get more power higher up the rev range meaning the engine will be working much harder than it was designed to do - leading to increased stress in the engine components and shorter engine life.

Finally to sell it you will need to put it back to standard- who will want to buy and insure an illegal machine if they are 16 and if they are 17 would they also not look for the larger 125cc bike?

Inview of the fact that it could also be illegal for you to ride the modified machine and increased likelihood of engine rebuilds I would save your money and invest in a 125cc machine when you are 17.

a standard four stroke will out perform a 70cc two stroke and will give you reliability and rideability.

Sorry to be negative but this way lays pain, MUCH MUCH PAIN, however if you want to learn a lot about rebuilding engines............

[Bennett]

Ahh best not do it then... :/ 1 more year and Ill have 125cc anyways

[Scotty]

That JayDee, he's a bad influence, he is.... ;D ;D ;D

[jonnydangerous]

i didnt do it! ;-)
oooh, maybe i did...

some bore kits dont have the cc marked on the side ;-) some even say 49cc!!! (naughty!!!).....

i once got pulled by plod for doing over 60mph on my RD50mx ont he way to salisbury, he was a mates dad and wanted to know how it was so fast, incase we could make his sons DT50mx a bit quicker :-)

there are a few good mods to perform without altering port area/open periods, that will keep the bike pretty reliable.
Bennett, give me a PM and il let you have my phone number.

jaydee.

[Thorkill_The_Tall]

So, I was told to get these by JD, so answer these for the newbie....

What is a Bore Kit?

What is a Racing Pipe?

What is the legality involved? :S

8-) thanks

Don't bother, young'un.
Spend the money on keeping the bike looked after and save the rest for your next bike.
The best money you can spend on any bike is for the petrol you use riding it

[jonnydangerous]

nooooooooooooooooo! speed speed speed! :-)
any improvement on a 50cc is TOTALLY well spent money hahaha....
send me a PM and il chat to you about it :-)

you CAN have power AND reliability :-)

[Cemorah]

Yep I remember trying to screw more out of FS1E's & AP50's but it was legal then. I agree most 50s are restricted for the UK market but at the risk of being a kill-joy a moped is now defined as:

"A moped has an engine not over 50 cc with maximum design speed not exceeding 50 kilometres per hour which is approximately 31 miles per hour"

If you de-restrict it it becomes a motorcycle! (in the eyes of the law) be careful - if you are caught at a young age it could be a pushbike next! :-[

Just my advice

[StreetHippo]

I'm with Jaydee :
Derestrict and gas flow it!!
Stu

[aprillia_dave]

if you want it go for it, I did it for my wifes brother er50, did 70mph with me on reving its nuts off. great fun poeple didnt exspect this speed froma moped! go for it you live once! SAFE RIDING!