Honda Spree and Elite 50 Forums

I bought the 49cc kit cylinder kit on e-bay to fix my DIO motor, since its meant for a toy for my son, i didnt bothered much. The thing is pure crap. after 1 week of usage, cylinder is out of round, rings are burned here and there, and comparision with the oem honda cylinder, the inlet ports are too much down so the port timing is completely messed up....
since i wasted 60$ i should have got the larger cylinder at least for 5 buck more....doh !

On another topic, does anyones ever bothered with engine dynamic balancing ? i would like to reduce vibrations as much as i can, given the fact that its gona be used at low rpm.

thanks.

Sounds like someone has no clue how to break in a new cylinder kit.

Bear45-70 wrote:Sounds like someone has no clue how to break in a new cylinder kit.

thats probably it. thanks.

Bear45-70 wrote:Sounds like someone has no clue how to break in a new cylinder kit.

+1

abreen89 wrote:

Bear45-70 wrote:Sounds like someone has no clue how to break in a new cylinder kit.

+1

ok, ok.

but that does not fix the port timing issue. they are all 0,060" down from the stock dio cylinder.

edit- they are more like 80 thou down !
i would need to put like 7 gasket under the cylinder to bring that to same height as the oem cylinder...and shave the head.

I beat the piston that comes with the kit sit further down... And if u would have checked it before final assembly u could have caught the issue and fixed it..... Not everything is bolt on even though is say it.....

Greetings:

Quoth The Bear:

Sounds like someone has no clue how to break in a new cylinder kit.

Now thar ya go ag'in. Don't be so hard on tha brotha, B. I had the same luck with a pair of Tai bores whose source shall remain nameless. I broke them in the same way as I did the Polini Contesta 65, the Malossi 65, the Nicasil 78, and the Corsa. None of those gave me trouble, yet I fried the first Tai kit within an hour of installation and the second in a couple of months. Sometimes it's easy to blame the User, but the quality of the metal and the precision and workmanship and matching the piston to the bore is the manufacturer's fault. The Italians (and some Asian) kits are simply better. That doesn't mean you can't compensate with finish work, but it seems to me you shouldn't have to.

Bad port timing will not cause the cylinder to go out of round. It will cause poor performance but improper break in and cheap oil cause excessive wear.

Greetings:

Yeah, but I used good oil and proper break-in with all of 'em. Only the cheapies failed despite that. Pride in workmanship seems supplanted by "crank 'em out quick and sell 'em cheap" philosophy. As If the buyer won't know the difference...

Wheelman-111 wrote:Greetings:

Yeah, but I used good oil and proper break-in with all of 'em. Only the cheapies failed despite that. Pride in workmanship seems supplanted by "crank 'em out quick and sell 'em cheap" philosophy. As If the buyer won't know the difference...

With the knowledge of the many members on this forum means that buying before checking with the forum proves that you are foolish twice at this time in scooterdom.

Greetings:

I'm proud to say I'm foolisher than only twicet. Then again, some Forumista report really good results with the same 51mm kits that failed me. I've got to conclude that it's possible to get lucky with the Piston/Bore match on some kits, and be very unlucky with others. Lacking the precision measuring equipment to get it just right means you rely on the manufacturer to do it. The Italians (and Nic) get it right For you - for a price.

Wheelman-111 wrote:Greetings:

I'm proud to say I'm foolisher than only twicet. Then again, some Forumista report really good results with the same 51mm kits that failed me. I've got to conclude that it's possible to get lucky with the Piston/Bore match on some kits, and be very unlucky with others. Lacking the precision measuring equipment to get it just right means you rely on the manufacturer to do it. The Italians (and Nic) get it right For you - for a price.

No you were one of the early experimenters, but now that knowledge is available.

I can see this problem of the op only getting worse he bought the cheapest stick kit now say he's going to buy a bbk..... So let's give him some info on how to setup up this new cyclinder correctly.... Like always check port timing before final install make sure ur postion and rings are within spec stuff like that....

every time i ask a question on this forum i get bashed on. i dont know what i am doing wrong.

for the takers, piston pin to deck is exactly the same so piston do not sit further down.
this kit is sold as a "direct replacement for dio motors, AF18E", so i dont see why in the * i would need to bother with such off spec stuff like that.

Cylinder height is exactly the same as the original dio one too.
So to me, they just machined the top and bottom of the cylinder 0,1 off the center, thats it.

I will make a shim of the proper thickness and mill the deck down. This will bring the all the ports as the same place as the dio one, and once i will mill the deck down, it will bring back compression ratio up.

patallen wrote:every time i ask a question on this forum i get bashed on. :*: i dont know what i am doing wrong.

for the takers, piston pin to deck is exactly the same so piston do not sit further down.
this kit is sold as a "direct replacement for dio motors, AF18E", so i dont see why in the * i would need to bother with such off spec stuff like that.

Cylinder height is exactly the same as the original dio one too.
So to me, they just machined the top and bottom of the cylinder 0,1 off the center, thats it.

I will make a shim of the proper thickness and mill the deck down. This will bring the all the ports as the same place as the dio one, and once i will mill the deck down, it will bring back compression ratio up.

Well... you admit that you bought the cheapest kit and it didn't work out. My question is what kit, exactly, and the seller. Would need that information to be able to figure out what was used. Then it's a Q of whether the break in was the issue, or the kit.

Rest of comment are around ensuring that the kit will work. The idea that most folks working on these bikes would check port heights, etc, post installation is optimistic in the extreme... most kids won't even check the running clearance before trying to fire it up. If they get all four bolts tight on the head it's considered an installation success.