My bike wont start

[CaptainLunatik]

Ok guys so here's the deal. So I bought a motorized bike from someone on offer up about a week ago ..It ran no problem from the second I got on it until now...Well basically I had seen on you tube a few different things I could do to increase compression and power whether it be torque or top end I was basically just trying to make my engine more efficient well anyways I modified the head by grinding off the little ridge around the gasket area of the head so as to make it all a flat surface ..Which in turn was supposed to give better compression well after doing that I went ahead and rebuilt the motor without grinding the piston to match the port in the cylinder. Because I wanted to see how the first modification went ....

Well I put it all back together and its not even trying to start.....I checked my plug I got spark I bypassed the kill switch just in case that was it...I been working on it all day and I'm so frustrated .....Any ideas anyone please

 

[CaptainLunatik]

So I sanded the head to make the joint between head and cylinder a better match which is supposed to increase compression. I was also going to grind piston to fit intake port. But after I did the head I put it back together and it wont start .....doesn't even try to start...the plug is fine its getting spark it's getting gas it's getting air......idk what else to do up until I sanded the head it ran fine just a little sloppy but at least it ran....any suggestions please I'm so freaking frustraited

 

[Tyler6357]

You should have sanded the cylinder to increase compression, not the head. How far down did you sand it? I bet it's leaking air at the head gasket.

 

[gary55]

Generally if it was running fine before you messed with something then the something you messed with is the first place to look. Check the compression.

 

[Spare_Parts]

X2, compression test.

Did you replace the base gasket(s)? If you sanded the head flat and used a new head gasket it could be the base gasket.

 

[CaptainLunatik]

I didn't replace any of the gaskets just used the old ones.....I need it to work it's my ride to work.

 

[CaptainLunatik]

So when I pedal it I have quite a bit of resistence when trying. too start it.......And I woke up this morning and a bunch of gas n stuff had come out of the exhaust while I was asleep......flooded maybe?

 

[gary55]

You need to take your carb. apart and clean it reset the float level.Their are youtube vids. on this. the reason your engine is flooded is because the float stuck and you left the gas petcock on over night. Then you need to pull the plug, clean it, and ride the bike around with the plug out and the engine engauged to evacuate the fuel from the crank case. You can also do this with a drill and a 14mm socket on the magnet nut rotating the engine with the clutch lever locked in. So whst is the compression? It may be ok and the flooding carb was the problem or the added resistance you were feeling was from the liquid fuel in the combustion chamber causing greater compression.

 

[Freddy Snottgrass]

Is it trying to start? In my experience the stock spark plug cable fails. I'm new to the hobby but my first bike ran for about a mile then stopped. After troubleshooting and pedaling my ass off I realized I had no spark. I bought a cheap coil wire from autozone, cut it in half and I haven't had a spark issue since. Get a drill and a socket that will fit on the magneto nut and see if you are getting spark. Make sure the drill is turning in the direction your engine rotates. My second bike wouldn't start on my initial trial so without testing I used the other half of my coil wire and it started right up. Since then I've only had one issue without it starting and that was due to running too rich and fouling my plug

 

[gary55]

Is it trying to start? In my experience the stock spark plug cable fails. I'm new to the hobby but my first bike ran for about a mile then stopped. After troubleshooting and pedaling my ass off I realized I had no spark. I bought a cheap coil wire from autozone, cut it in half and I haven't had a spark issue since. Get a drill and a socket that will fit on the magneto nut and see if you are getting spark. Make sure the drill is turning in the direction your engine rotates. My second bike wouldn't start on my initial trial so without testing I used the other half of my coil wire and it started right up. Since then I've only had one issue without it starting and that was due to running too rich and fouling my plug

He said he has spark in reply #1, but no harm in checking it after he is finished evacuating the liquid fuel out of his crank case. Might wanna dry up any fuel that may come out of that plug hole before checking the spark Captain.