Sorry you couldn't figure out what is wrong, it sounds like it's running very rich for some reason and it's flooding out. Send it back and get a new engine is all I can say.
Brand new engine wont stay running
- Thread starter Indy420
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I don't know. I don't see how two brand new carbs can have the exact same symptom.
I think there is a problem in the magneto, which is causing it not to fire, which is causing it to flood out.
It was running pretty good earlier today. I'd shut it off and restart it just fine. Once it sits for 15-20 minutes, it's done. It won't restart till the next day.
I have personally had the same problems the two wires coming out of the coil are messed up some times they'll work fine for a bit sometimes wiggle them a bit i willing to be that's the problem
I know these things can get frustrating. There is a learning curve with this hobby for sure. I was a total rookie when I got my kit, I had some of the same troubles and thoughts that you probably are having. I know its frustrating to buy all new parts and still not solve the problem you are having. My first engine lasted about 500 miles until the needle bearing broke apart and went through the cylinder destroying my piston and parts of it got shot out the exhaust pipe. I took the entire engine apart including splitting the crank case to try to learn what broke, and to try to understand all I could about how these engines work. I never really tried to fix it, I decided to just get another engine instead. When I found out about balanced cranks and better bearings I got a better engine. They are relatively inexpensive little engines and not always worth it to bother fixing but I learned quite a bit taking it all apart. Other things went wrong for me too but nothing I couldn't fix and figure out how to keep it from happening again. After awhile I was able to get all the kinks worked out and it became reliable. I learned which screws vibrate loose and which ones don't. You should carry some basic tools with you while you ride it, at least for a while in case something happens on the road, it could save you from walking or peddling it home. but there is a light at the end of the tunnel.
Intermittent Magneto is something that can be doing this maybe. I not sure except for a recent post you said the Magneto and CDI were fine. I though there was a new replacement of the magneto in the mail to you. Did you try it? If you have it definitely give it a try. I wore out my arm trying to start that used Coleman generator that was gifted to me. Then a magneto was it.
Itermittant problems are hard to figure. The bike not able to restart after sitting a while I would wonder if fuel is some how continuing to flow even if the engine is not drawing a vacuum when not running. Even if the fuel valve is shut off there is enough fuel in the bowl of these gravity feed fuel systems to maybe flood and engine.
I returned a carb I got that always was doing this. I'd even bet another of the same brand would have done that again if I had just a replacement. I went back to using a old tested carb I had. Sure it was one without an idle adjustment, which is why I got the newer carb, but some stuff is just not good because it is new. The seat and float needle valve I could never get set right. If fuel is not fowled with anything, then the fuel should not flood the engine if float adjusted right. The height of the fuel tank I would hope has a range that it can work with on the frame and not cause any issue.
I want to add this about some design of carbs. The one I returned I noticed that flooding could happen when the engine was running even if the float valve was operating properly. There was a seal that was used along with the mounting of the bowl nut/main jet that was supposed keep fuel from bypassing the main jet. If that seal leaked, the main jet was completely compromised.
Itermittant problems are hard to figure. The bike not able to restart after sitting a while I would wonder if fuel is some how continuing to flow even if the engine is not drawing a vacuum when not running. Even if the fuel valve is shut off there is enough fuel in the bowl of these gravity feed fuel systems to maybe flood and engine.
I returned a carb I got that always was doing this. I'd even bet another of the same brand would have done that again if I had just a replacement. I went back to using a old tested carb I had. Sure it was one without an idle adjustment, which is why I got the newer carb, but some stuff is just not good because it is new. The seat and float needle valve I could never get set right. If fuel is not fowled with anything, then the fuel should not flood the engine if float adjusted right. The height of the fuel tank I would hope has a range that it can work with on the frame and not cause any issue.
I want to add this about some design of carbs. The one I returned I noticed that flooding could happen when the engine was running even if the float valve was operating properly. There was a seal that was used along with the mounting of the bowl nut/main jet that was supposed keep fuel from bypassing the main jet. If that seal leaked, the main jet was completely compromised.
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The new magneto and CDI should arrive today. I will install it as soon as it gets here.
Thanks, Troy
bummer that you're going thru all this - at my shop, it usually takes 10 to 15 minutes to sort out a non-start problem
for a new rider, this is not the case tho, as it takes some knowledge specific to these little POSs to spot the cause that quickly, so many folks just keep replacing good parts with new good parts and hope for the best
in your case, you will need to work hard to get familiar with these and understand how all the parts work together, or find someone in your area to help you, or get another one that works well and part by part compare the two
keep in mind that these are simple with only about 12 moving parts in the whole thing
for a new rider, this is not the case tho, as it takes some knowledge specific to these little POSs to spot the cause that quickly, so many folks just keep replacing good parts with new good parts and hope for the best
in your case, you will need to work hard to get familiar with these and understand how all the parts work together, or find someone in your area to help you, or get another one that works well and part by part compare the two
keep in mind that these are simple with only about 12 moving parts in the whole thing
The first one I built last summer started right up. Never had a problem. I just sold it for $400 2 weeks ago. This one is a nightmare. I've been working in transmission shops for the past 20 years, so I kinda know what I'm doing. After I build a few more I should know what to look for when, and if these problems ever happen again.
I've had less problems working on a v8. lol
I'm trying to start a business selling these things. You never see these in my city. People love these things. The new moped laws require a drivers license to ride a moped above 49cc here in my state. These bikes are exempt from all laws. I know I can sell lots of these. I've already got this bike sold if I can get it running. I'm asking $600 for this one.
My new magneto, CDI, and plug wire should arrive in about an hour. I'll post pictures of the burning pile of scrap metal if it doesn't run.
it takes seeing 6 or 8 of these with problems to get a feel for them - seeing a large number with no problems doesn't help at all
hardest thing is customer swaps top end and throws away old one, then has good running, but low power issues - this is often a port mapping problem, but without the old one to measure against, one is sometimes just stuck
hardest thing is customer swaps top end and throws away old one, then has good running, but low power issues - this is often a port mapping problem, but without the old one to measure against, one is sometimes just stuck
UPDATE:
Installed a new magneto, a new CDI, and a new plug wire. This P.O.S. still wont run!
WTF?!?!?!?!
Installed a new magneto, a new CDI, and a new plug wire. This P.O.S. still wont run!
WTF?!?!?!?!
REPLACED:
Carb
spark plug (gapped at .024 then again at .027)
magneto
CDI
plug wire
fuel
fuel line
CHECKED:
for dirt in tank (cleaned tank, put in fresh gas)
petcock flow (drained tank using petcock, it has good flow)
exhaust (unhooked it)
floats (adjusted both ways)
kill switch (unhooked it)
throttle needle (adjusted multiple times)
head bolts (they were slightly loose, tightened up with 3/8 ratchet, no torque wrench, did it by feel. I'm a mechanic)
FUEL RATIO:
I have it around 21:1 (It does not matter. I should be able to fire this thing up on straight fuel and run it till it blows up)
My last motorized bicycle was at 16:1 and it ran perfect.
WHAT IT'S DOING:
Starts hard. Once it's started I can ride it for a couple miles. I can shut it off and restart it fine. Once I shut it off for more than 10 minutes, I'm done. It has to sit for 15 hours before it will start again. Then it's the same way all over again.
It backfires when trying to restart it after letting it sit.
When I do get it running it feels like it's going around 30mph. It does not feel like it's running at 100%. It feels like it's "4 stroking".
WHAT I DO KNOW:
I know it is not my gas, or my gas/oil mixture.
I know it is not my carb. What are the odds of 2 carbs having the exact problem.
I know there is no dirt in my tank.
I know my petcock is not plugged.
I know my fuel filter is not plugged.
I know I have good fuel flow to my carb.
I know there is no dirt in my carb.
I know my exhaust is not plugged. I can blow through it. I loosened the 2 manifold bolts up and pulled the exhaust pipe back away from the engine about 1/2 inch and it didn't make a difference in how it ran.
WHAT I DO NOT KNOW:
I do not know how to adjust this new magneto. I do not have a feeler gauge. I am going to do a search right now and teach myself.
WHATS NEXT:
Milwaukee SAWZALL!!!!
Carb
spark plug (gapped at .024 then again at .027)
magneto
CDI
plug wire
fuel
fuel line
CHECKED:
for dirt in tank (cleaned tank, put in fresh gas)
petcock flow (drained tank using petcock, it has good flow)
exhaust (unhooked it)
floats (adjusted both ways)
kill switch (unhooked it)
throttle needle (adjusted multiple times)
head bolts (they were slightly loose, tightened up with 3/8 ratchet, no torque wrench, did it by feel. I'm a mechanic)
FUEL RATIO:
I have it around 21:1 (It does not matter. I should be able to fire this thing up on straight fuel and run it till it blows up)
My last motorized bicycle was at 16:1 and it ran perfect.
WHAT IT'S DOING:
Starts hard. Once it's started I can ride it for a couple miles. I can shut it off and restart it fine. Once I shut it off for more than 10 minutes, I'm done. It has to sit for 15 hours before it will start again. Then it's the same way all over again.
It backfires when trying to restart it after letting it sit.
When I do get it running it feels like it's going around 30mph. It does not feel like it's running at 100%. It feels like it's "4 stroking".
WHAT I DO KNOW:
I know it is not my gas, or my gas/oil mixture.
I know it is not my carb. What are the odds of 2 carbs having the exact problem.
I know there is no dirt in my tank.
I know my petcock is not plugged.
I know my fuel filter is not plugged.
I know I have good fuel flow to my carb.
I know there is no dirt in my carb.
I know my exhaust is not plugged. I can blow through it. I loosened the 2 manifold bolts up and pulled the exhaust pipe back away from the engine about 1/2 inch and it didn't make a difference in how it ran.
WHAT I DO NOT KNOW:
I do not know how to adjust this new magneto. I do not have a feeler gauge. I am going to do a search right now and teach myself.
WHATS NEXT:
Milwaukee SAWZALL!!!!
QUESTION.
In the video's I am seeing and in all the pictures I am seeing, the magnet that sits in the magneto has the key-way slot positioned at the 1 o'clock position. Mine is at the 12 o'clock position. I will post pictures in a minute.
In the video's I am seeing and in all the pictures I am seeing, the magnet that sits in the magneto has the key-way slot positioned at the 1 o'clock position. Mine is at the 12 o'clock position. I will post pictures in a minute.
What are the odds of 2 carbs with the same problem? Pretty damn good. Most come pig freakin rich anyway. Maybe your engine has good enough compression and needs a smaller jet. The little pos carbs on these engines only have a single jet for all ranges of rpm. Buy some micro bits. You can buy them at a hobby store. Use the bits to figure out your current size. Use some solder to close the jet hole off, then drill it a few sizes smaller.
That's if it is, in fact, 4 stroking. There's bogging, and 4 stroking. 4 stroking is when you hear a machine gun from the engine and the rpm sounds like 1/2 what it should be. That's because the mixture is rich. If it's bogging, it just won't go. Period. That means it's lean.
Does it wear you out while pedal starting? You hear good compression on the cylinder? You have a new cdi, magneto, all that jazz. You have spark. (you cant adhust the magneto, btw). Air, fuel, spark, compression. You get those in the right proportion, you get a running engine.
That's if it is, in fact, 4 stroking. There's bogging, and 4 stroking. 4 stroking is when you hear a machine gun from the engine and the rpm sounds like 1/2 what it should be. That's because the mixture is rich. If it's bogging, it just won't go. Period. That means it's lean.
Does it wear you out while pedal starting? You hear good compression on the cylinder? You have a new cdi, magneto, all that jazz. You have spark. (you cant adhust the magneto, btw). Air, fuel, spark, compression. You get those in the right proportion, you get a running engine.
See new update above:
"QUESTION.
In the video's I am seeing and in all the pictures I am seeing, the magnet that sits in the magneto has the key-way slot positioned at the 1 o'clock position. Mine is at the 12 o'clock position. I will post pictures in a minute."
I've seen that on a few, but haven't looked into it much yet - my best guess is that the one with slot closest to vertical is used on the newer balanced cranks, which may have the slot cut in them in slightly diff position from the older cranks. Haven't seen a problem with that yet as long as the rotor & crank are used together, swapping one of those rotors with the other type might cause a problem.
It sounds like its so rich that it almost fouling the plug, I've had that happen to dirt bikes. Have you tested it without the air cleaner? If it runs better it definatly rich, not oil to fuel rich but fuel to air rich. (Jetting)
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