Break In Chinese YD100 no power

[MinimumVK]

Hello! So I bought a chinese YD100 kit from a german seller. Anyways i installed it onto my frame and tried to start it... I spend about 30 minutes trying to start it. Was checking if it was getting fuel, if the plug was wet all those things. It was backfiring like crazy at first. After about 30 minutes it started but would not idle. After about 15 more minutes of trying i got it to idle but the throttle response was non-existent. Again after about 15 more minutes it started responding to my throttle inputs. Tried to ride it and it bogs down when i get it going. I let it run for 15 minutes and rode it on a flat road for about 30 minutes but when i came to a hill i wanted to die so i had to pedal with it. Is it normal that it has no power at all while in break in. Before putting the engine on the frame i checked all of the bolts and such and i found out that it had no gasket between the cylinder and the case (it has a 1 piece cylinder and head). I made my own out of gasket paper. There are no obvious air leaks. The needle pin is set on the 3rd groove from the bottom. Should i try tweaking with the carb first? Thanks in advance!

 

[MinimumVK]

UPDATE: I tightend the head bolts and crankcase bolts when the engine was cold. They werent tight and after that if i would spray carb cleaner on the case the idle just dropped a little bit (not that much that it would die). I also recorded a video of it running so you can hear it. (It has a weird sound coming out of the carb like it would be blowing back). Also when i cold start it, it backfires and smokes comes out of the airfilter. Just to ask... these engines are suppost to have gaskets on the cylinder because it didny have it from the factory (i made my own but dont think that would mess something up)
Here is the YouTube link of the engine running:

 

[DAMIEN1307]

(i made my own but dont think that would mess something up)

Depends on how thick the gasket is that you made...Most of these motors come with double gaskets on them and needless to say, the thickness does effect the height of the cylinder jug which effects the overall engine timing when running...The backfiring and excessive blowback into the carby was your first clue.

 

[MinimumVK]

Depends on how thick the gasket is that you made...Most of these motors come with double gaskets on them and needless to say, the thickness does effect the height of the cylinder jug which effects the overall engine timing when running...The backfiring and excessive blowback into the carby was the first clue.

Interesting. I made a gasket out of an old notebook cover (we did this on mopeds and it worked fine) I guess i will take the cylinder off and try to find something thinner. But still why wouldnt the factory install a gasket. I know some 2 strokes dont need cylinder gaskets because it seals with a taper.

 

[GW's Motorized]

Quality control isn't the best with these engines

 

[DAMIEN1307]

Interesting. I made a gasket out of an old notebook cover (we did this on mopeds and it worked fine) I guess i will take the cylinder off and try to find something thinner. But still why wouldnt the factory install a gasket. I know some 2 strokes dont need cylinder gaskets because it seals with a taper.

Like anything else made in China...Their expert 12 year old quality assurance people didn't pack the gaskets with the motor kit...lol...lol...Very common to have missing items in alot of these kits, especially when they come from E-bay vendors.

I know some 2 strokes dont need cylinder gaskets because it seals with a taper.

With a taper???...lol...Not very bloody likely coming from China with these motors...lol.

 

[MinimumVK]

Ok thanks for the info. I guess i will try to make a thinner gasket and come back with an update.

 

[DAMIEN1307]

Ok thanks for the info. I guess i will try to make a thinner gasket and come back with an update.

Just order these gaskets for the bottom end, use both of them and be done with it the easy way...Only $1.99 for the pair...I don't Know if they will ship to Slovenia though.

Cylinder/Crankcase Gasket 2 Pack (Part #7)

Your source for 2-Stroke and 4-Stroke Bicycle Engine Kits, Performance Parts, and Accessories!

www.bicycle-engines.com

Or contact wherever you got the kit from and tell them it didn't come with the two bottom gaskets and have them send them to you which should be free since they are supposed to come with them.

 

[Chainlube]

Ok thanks for the info. I guess i will try to make a thinner gasket and come back with an update.

Before you do that, get a length of solder and put it in the spark plug hole and up against the side of the cylinder. Turn the engine over, i.e. roll bike, and then measure how thick the piece of solder is on the end. Should be .7-.9mm.

 

[MinimumVK]

I tried contacting the seller about this but i would have to send the kit back to them which is too complicated at this time... Im also not paying $20 for shipping for a $2 gasket set. Does anyone know what thickness the gasket or gaskets together should be?

 

[MinimumVK]

Before you do that, get a length of solder and put it in the spark plug hole and up against the side of the cylinder. Turn the engine over, i.e. roll bike, and then measure how thick the piece of solder is on the end. Should be .7-.9mm.

I tried this (hopefully you meant by the exhaust side of the cylinder since the spark plug hole is angled like that) and it just kinda grabs the solder but doesnt actually pinch it.