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Bennett
18-12-09, 10:24 AM
:D

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
18-12-09, 05:06 PM
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
18-12-09, 06:59 PM
Ahh best not do it then... :/ 1 more year and Ill have 125cc anyways

Scotty
19-12-09, 03:09 PM
That JayDee, he's a bad influence, he is.... ;) ;D ;D ;D

jonnydangerous
21-12-09, 04:05 PM
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
21-12-09, 11:26 PM
:D

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
22-12-09, 01:28 PM
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
22-12-09, 06:40 PM
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
06-01-10, 01:09 AM
I'm with Jaydee ::)
Derestrict and gas flow it!!
Stu

aprillia_dave
06-01-10, 12:21 PM
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!

Kevinb
06-01-10, 03:07 PM
Apparently you can get a 2.1 Ltr big bore kit for my MT-01. ;D
Now that would be mad

Jon_W
22-01-10, 02:34 PM
:D

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.... the best bore kit you can buy is a bigger bike....

Bore kits are legal but you will need to tell your insurers that the bike is modified and it will still have to pass the emissions test for the original engine.

Racing pipes are not road legal if they are too loud or marked "not for road use" or "for race use only". Again you will have to tell your insurer that the bike is fitted with a racing system. A lot of insurers will not insure a bike fitted with a non-road legal exhaust.

My advise is keep the 50cc in as good a condition as possible, maximise the re-sale value. Flog the 50cc get a 125cc, do the same maximise the re-sale, get a full lisence, flog the 125 and buy a big bike. Lots more speed!!!

jonnydangerous
27-01-10, 01:39 PM
like i said, if you want to PM me for tuning data please do.

life is for LIVING...... :-)

Thorkill_The_Tall
27-01-10, 10:26 PM
like i said, if you want to PM me for tuning data please do.

life is for LIVING...... :-)


Yeah - and it certainly ain't living when you're having to catch a bus because you've been a complete knob and blown your engine because of some dodgy big bore kit and badly made can.
Do as you wish, kiddo, it's your money.

Why are humans the only animals who fail to learn from the previous generation?

Davey
28-01-10, 02:10 PM
I've run big bore kits on numerous bikes with no ill effects apart from extra aching muscles in my face from extra smiling :)

If it is done right and within the tolerance of the bike and corners not cut to save money - now't to worry about! Manufacturers do it all the time!

But as mentioned before you should mention it to your insurance etc wouldn't want you to be illegal on a bike

Thorkill_The_Tall
28-01-10, 06:00 PM
I've run big bore kits on numerous bikes with no ill effects apart from extra aching muscles in my face from extra smiling :)

If it is done right and within the tolerance of the bike and corners not cut to save money - now't to worry about! Manufacturers do it all the time!

But as mentioned before you should mention it to your insurance etc wouldn't want you to be illegal on a bike
I agree, Stu, but the key words are 'done properly'.
How many of the bolt on kits for small bore two-strokes take into account any increased oiling for the crank, etc, etc?
These kits are, more often than not these days, cheap, nasty and made from recycled Pandas in Chinese sweatshops.