Question about big bore kits for a baja sc 50

[completenoob]

Hi all, I know this isn't a scooter forum, but unfortunatly all the other scooter forum sites have very low traffic on them and I was thinking that my question would go unanswered.

Long story short, I have a baja sc 50 scooter (generic chinese brand from pep boys) i bought off a friend real cheap. was considering getting a 80cc big bore kit put on, but i just recently read something that it can damage the engine

I found the following on yahoo answers, and this is the only information i could find ANYWHERE on the internet:

"when putting a big bore kit in you have to be sure your cylinder walls are think enough if there not and you still put it in you could warp the walls and loose compression so yes it could damge it

big bore kits blow the bottom end bearings. Ive been there and done it ,it is fun until it lasts. i don't recommend putting a big bore on your bike."

This information vs what I've heard from friends who have had it done to theirs and from local shops I have called said that they have never heard of a big bore kit, and more specifically, on a sc 50, ever getting damage from it.

I was curious as to why someone would even make something that would eventually screw up an vehicular investment such as a scooter in the first place, especially when your average big bore kit is roughly 200-300 bucks, on top of what you already pay for your scooter....just doesnt make any sense to me, but hey, if you pay to put something on your scooter, have to get messed up a year later, and take it back to the same person to get fixed, then i guess it kinda makes sense...nonetheless its still messed up business practice.


I was just wondering if anyone is knowlegdable in this field, any responses are more than welcome, thanks!

[FNA]

I don't know why you have any questions. You have found a website that says if your engine is in too poor of shape to be fitted with a big bore kit, you should not fit a big bore kit.

That's a surprise?

You know why bottom ends blow after a top end has been blown so bad it needs a bore job? Because the bike was ridden so hard it needed a bore job and the bottom end should be replaced anyway.

There is no replacement for displacement, but

If it will cost you $300 for a big bore kit, why not look around and buy a real used motorcycle? I bought a 750 BMW in running condition two years ago for $1700. You ought to be able to get a Honda 250 for a few hundred.

[MagicRat]

Originally Posted by FNA

I don't know why you have any questions. You have found a website that says if your engine is in too poor of shape to be fitted with a big bore kit, you should not fit a big bore kit.

I think this thread is pretty academic, since such kits are not available.

Any 50cc scooter is just basic transportation anyways, especially for ther newbie rider.
As noted above, if it's too slow now, simply sell it and buy something bigger. Most riders' developing skill level allow them to outgrow their first bikes pretty quickly.

Personally, I have had some success with tiny air-cooled 2-strokes by removing the head gasket (use a thin layer of Loctite Ultra-copper sealer in its place), high-octane gas and a proper carb adjustment. With experience and a sharp ear I can tell when I have arrived at the best adjustment for max power.

Chances are, though, that the engine's bottom end will not tolerate a power increase and break. Then your scooter will be worth approx. $0.00