New motor won't fire up?

GoldenMotor.com

bp88

New Member
Sep 13, 2012
7
0
0
Orange County, CA
I'm posting this thread for my dad who recently installed a new motor kit from China. I realize that you usually get what you pay for but he didn't want to spend a lot on this project because the bike is only going to ridden every now and then. It's a 50cc single cylinder 2-stroke.

Anyways, last night we finally got everything together and went to fire it up but it didn't start nor did it even try to. We have fresh fuel coming through and good spark. We even tried spraying starter fluid directly into the cylinder and still nothing. The only thing I can think of is air flow/compression but it's a brand new motor.

Any ideas?
 

JonnyR

New Member
May 13, 2012
1,203
1
0
37
ronkonkoma, new york
if you are getting spark is it in the right place 2 people have had this problem from the magnet being in backwards in the magneto there is a post if you search for the magnet orientation which will tell you if its backwards also check to see if the plug is gaped right most are around .030. if thay arnt the problem check the carb out it might be a internal issue like the barrel slide is in wrong
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
assuming your wiring's correct and not grounding out, if you've got fuel and spark, there's another issue.

you say it's not trying to start. what do you mean? is the motor going through the compression stroke (and going "thup thup thup") or does it feel like there's no compression?

the clutch cable may be adjusted too tight. when you pedal and release the clutch lever, there should be a noticeable amount of compression to kick it over. if it's still easy to pedal, loosen the clutch cable.

if you push the bike with the clutch lever released, the back wheel should skid.

also, you said you have fuel, but is it actually getting into the carb? check to make sure the float bowl is full. make sure there's no intake leak as well.

keep us posted..
 

bp88

New Member
Sep 13, 2012
7
0
0
Orange County, CA
I told my father to purchase an NGK plug and wire later today. He told me he gapped the original plug at .20 (derp!) so he'll gap the new one at .30.

I also thought there wasn't any fuel getting into the cylinder but he said when he pulls the plug he can smell gas; however, with the amount of time we've spent trying to get it to fire up we should've flooded the motor way more than what we're seeing so I too personally think it's a fuel issue.

The compression is good and the clutch is adjusted properly, it's just not firing up at all.

I will let him know about the magnet issue and deal with the rest of the issues then get back to you guys. Thanks so much for the help, guys!
 

bp88

New Member
Sep 13, 2012
7
0
0
Orange County, CA
Sorry for taking so long to reply.

We actually discovered that ours wouldn't fire up because the clutch was slipping. My dad originally thought that the motor required oil in the crankcase but he was later told it doesn't, so he drained it out and apparently there was enough left in there to cause the clutch to slip. He cleaned the remainder out and all is working fine now.