Kymco ZX50

[sidthesloth]

G'Day all, have decided to go with a cylinder kit, hopefully that will help, if not with starting then at least with performance. They seem rather expensive here, $339, in America they sell for around $199 which works out to $225 Australian at the current exchange rate.

[zombie]

Which kit are you going with?

[sidthesloth]

Hi, I'm going to try a 50mm kit from taiwan, I figure the scooters are made there so the kit should be ok. Obviously cheaper than anything I can get locally. If it is a mistake I only have myself to blame. This is my first time so hoping for the best.

[zombie]

Before you order check the wrist pin size on your scoot. MOST zx's are 10mm, but some have 12mm. That will determine which piston to order.

[sidthesloth]

Hmm, I have already bought it, I didn't know some had a 10 mm pin. may have made my first mistake. Still, I won't pull it apart until the bits arrive as I am still using the scooter. thanks for the warning.

[zombie]

Not to jump ahead, and create trouble where there is none. Your supplier may have the 50mm piston in both wrist pin sizes. You will also want to open your main , and idle jets to get the new jug working right. I found torch tip cleaners work great. You can open the jets slightly until you get a good mix ratio, and not have a pocket full of extra useless jets. Hey man ps, I love the avatar. I tried to upload several animated avatars, and couldn't get them to run.

[sidthesloth]

Thanks zombie, I will need all the help I can get with the tuning so be warned I will be hounding you for info as I go. for the avatar I just googled ice age avatars and picked the one I wanted, Sid, of course.

[wordslinger]

Not to jump ahead, and create trouble where there is none. Your supplier may have the 50mm piston in both wrist pin sizes. You will also want to open your main , and idle jets to get the new jug working right. I found torch tip cleaners work great. You can open the jets slightly until you get a good mix ratio, and not have a pocket full of extra useless jets. Hey man ps, I love the avatar. I tried to upload several animated avatars, and couldn't get them to run.

..not meaning to hi-jack ur thread or nothin', sid..but.......

..zombie..they may have been too "big"...there's a limit on the file size for ur profile pic...dunno what it is..

..animated pics are usually gif files, and usually aren't very large unless there are a bunch of frames..

..that may have been your problem..

[zombie]

Yeah, that's why I tried several. Just couldn't find the magic number. Is there a way to reduce the file size?

[wordslinger]

..not with the animated gifs...well, there is...but u gotta save each frame...edit and down-size them...it's waaaay too drawn out...lol...

[sidthesloth]

G'Day zombie, with regards to the piston pin size, having checked the service manual it shows as 12mm. This is for the SC10AS engine which mine is. This manual was printed in 2000 and my scoot is a 2007 model so they may have changed it in that time but I think they would have changed the engine model code if they did, here's to hoping. Will find out for sure as soon as it turns up.

[sidthesloth]

G'Day all, the 50mm cylinder kit turned up today so tomorrow I will find out for sure if it will fit. comp. tester turned up as well so will see what that tells. Has been a long time since I have had any trouble with the police and hope to keep it that way.

[Shaka]

Good deal Sid!  Almost sounds like x-mas!  Stay away from the cops!  I figure I was due, it's been almost a year since the last time I got stopped on the scoot.  The way I figure, at least it wasn't for anything serious!

[sidthesloth]

G'Day All, did compression test on Sid today, 105 psi, I don't know what the limit is but that doesn't sound too bad. Fitted the cylinder kit today also, piston pin was a 12mm one so that was a relief, the only thing I had to do to accomodate the larger barrel was file a bee's dick off the inlet manifold, the cooling covers went back on but did not quite meet up perfectly at the top, the spark plug cap sits a little proud of the covers. Sid is now 82cc. Now for the problem, after about ten minutes of riding she seems to get hot and sieze, allow to cool for a few minutes and starts again ok. Is this to be expected until the piston/rings/barrel wear in or should I be using mineral oil until worn in or perhaps increase the oil flow, (I am still using the original oil pump). This job has been both an experience and fun to boot. You blokes are an inspiration, thank you for your encouragement and advice, it is much appreciated.

[zombie]

ASAP Either add 3/4 oz 2t oil per tank, or zip tie the injector pump open. The pump goes as low as 100:1 at idle, and 40:1 full thrott. You need at least 50:1 to wear in the rings. Did you check the end gap? It should be between 2-5 thous. Have you re-jetted? The easiest way to tell what is happening is check the plug. Also do what you can to reseal the engine shrouds. If air is getting out, it is not cooling. Try these few things, and let us know. Hey Congrats on the new baby! It'll be screaming by the end of the week!