Hi. Super newb here. I recently bought a 49CC engine kit from ebay seller boygofast and installed it on my 70's free spirit cruiser. After a good amount of tweaking (tightening the clutch cable, adjusting choke, securing wire connections, etc.), I was finally able to get it going. It seemed to be running OK, but I didn't really ride it around much—just around the block a few times. The next couple of days I had a harder time starting it and/or keeping it running. I read through a number of threads relating to starting problems and noticed there was a decent amount of smoke leaving the exhaust, and thought perhaps the mixture was too rich. So I decided to increase the fuel to 20:1, instead of 16:1. After that it seemed to be running much better. The engine sounded robust and it accelerated great. A lost idle screw and a few days later, I began experiencing similar symptoms as I did before, and now I can't get it to start at all. There were a couple of times after letting up on the clutch that the drive chain and rear wheel would lock up, so I suspected that the engine might be flooded. Accordingly, I pulled out the plug and rode it around with the engine engaged to try and dry things up. Still no go. I replaced the stock plug with an NGK B-4L, though both plugs get spark. Interestingly, there is no visible smoke leaving the exhaust. The kill switch is disconnected, though it doesn't seem to matter if it's connected or not. Any suggestions for an ignorant newcomer?
The Engine Starting Blues
- Thread starter TheSereneOutsider
- Start date
Sounds like a fuel problem, some have had the main jet to fall into the bowl of the carb. I would pull the carb and check for debris.
If you've done any reading then you have to have seen this:
The engine needs three things to run, fuel, air and ignition. Test for these and let us know what you find.
Fuel flow from tank to carburetor?
Choke plate open?
Spark?
Tom
The engine needs three things to run, fuel, air and ignition. Test for these and let us know what you find.
Fuel flow from tank to carburetor?
Choke plate open?
Spark?
Tom
Fuel Flow:I disassembled the carburetor. Fuel appears to be flowing to the carb, as the carb bowl was completely full of fuel, although it looks as though the fuel line is leaking where it fits onto the carb.
Choke: I've tried starting the motor with the choke lever at various positions—on, off, half-way, two-thirds of the way up, two-thirds of the way down, etc. From what I can tell, it doesn't appear to have much bearing on how close it sounds to starting. Previously I had consistent success starting the engine with the choke lever in the upward most position.
Spark: I can see spark coming from the spark plug when I remove it, engage the motor and push the bike. The spark plug isn't wet, but does smell of fuel. I've tested with two different spark plugs.
Almost sounds like you may have developed a vacuum leak somewhere. Did you check your carb to manifold sealing? And although it sounds like you still have compression, have you checked the torque on your head bolts after all that previous running?
Have you pulled off the magneto cover to see if all is tight, you said it was firing but if the mag. has gotten loose or sheared the key you could be out of time. Also look for fuel in that area that would indicate a blown seal behind the magneto. It would be a good idea to pull the clutch cover off and look there for fuel also.
Thanks for all the replies. Working on this engine has been immoderately frustrating, and it's awesome to get some helpful feedback.
I turned the bike upside down and slowly turned the wheel and dark fuel sputtered/dripped out of the head. Not a whole lot, but a small puddle worth. I rode it around with the spark plug removed, and then tried starting it but still no go. I was getting visible smoke when starting before (back when it would start), now I don't get any at all.
maintenancenazi, I wrapped up the carb to engine manifold with teflon tape in hopes that would ensure a better seal. I've inspected the carburetor and nothing seems out of order. I will note that I am using a replacement idle adjustment screw, which I have not yet rounded. However, it was running OK with it missing. I would just kill the engine whenever I needed to come to a stop, and then start the engine back up again.
Greg58, Unfortunately the bike fell over and landed on a loose socket bit on the floor, leaving a hole in the magneto assembly cover. I was concerned this fall may have damaged the magneto. Nothing is loose and the magneto is dry. There is some fuel on the outside cover, but that appears to have come from a leak from the carburetor. How do I tell if the magneto key is sheared?
I turned the bike upside down and slowly turned the wheel and dark fuel sputtered/dripped out of the head. Not a whole lot, but a small puddle worth. I rode it around with the spark plug removed, and then tried starting it but still no go. I was getting visible smoke when starting before (back when it would start), now I don't get any at all.
maintenancenazi, I wrapped up the carb to engine manifold with teflon tape in hopes that would ensure a better seal. I've inspected the carburetor and nothing seems out of order. I will note that I am using a replacement idle adjustment screw, which I have not yet rounded. However, it was running OK with it missing. I would just kill the engine whenever I needed to come to a stop, and then start the engine back up again.
Greg58, Unfortunately the bike fell over and landed on a loose socket bit on the floor, leaving a hole in the magneto assembly cover. I was concerned this fall may have damaged the magneto. Nothing is loose and the magneto is dry. There is some fuel on the outside cover, but that appears to have come from a leak from the carburetor. How do I tell if the magneto key is sheared?
Try the link below it may help.
https://docs.google.com/document/d/1aBeJuoS--VQWwXysc07rpscTUbPzgc93xjiQBgsyFjc/mobilebasic?pli=1
https://docs.google.com/document/d/1aBeJuoS--VQWwXysc07rpscTUbPzgc93xjiQBgsyFjc/mobilebasic?pli=1
Here is another good thread that might help.
http://motorbicycling.com/f4/motorized-bicycle-carburetor-pictures-how-install-195.html
http://motorbicycling.com/f4/motorized-bicycle-carburetor-pictures-how-install-195.html
Update: I took the bike down to a shop (Lar-eez motor bike shop, for anyone in the Boise area—really terrific guy) and had it checked out. In about five minutes he narrowed down the issue to a blown crank seal, and soon discovered about five missing ball bearings in the crankshaft. I suppose she's done for. Thanks for all the help.
Out of curiosity, does anyone have any ideas about what might have happened to those four or five missing ball bearings?
How long have you had the engine? I have had good luck so far with problems with BGF kits. I would e-mail them and tell what happened, if nothing else they may make you a deal on a new lower end only. They show it in stock.
http://www.ebay.com/itm/Motorized-B...Cycling_Parts_Accessories&hash=item27bb4df3e7
http://www.ebay.com/itm/Motorized-B...Cycling_Parts_Accessories&hash=item27bb4df3e7
It sucks that your motor died, but why not take the opportunity to rip it apart to at least learn more about how it works, if not fix it? You can buy the seal and new bearing ring cheap enough, so if you are lucky enough not to have anything else damaged in the bottom end you should be able to fix her up...
The top end comes off super easy, the bottom end is more difficult but doable, you need to use the gear puller tool that should have come with your kit to get a few parts out of the bottom end.
Which seal/bearing blew on ya', the one under the magneto?
You had Good Luck with motor problems Greg?
A problem is a problem, there shouldn't be any to start with in my opinion.
That ~$25 or so you save buying a 3rd rate motor kit off Ebay opposed to a Skyhawk is directly related to quality parts like Japenese bearings that Skyhawks use in crucial area's that cheap kits don't.
Don't get me wrong, Skyhawks can and do have problems sometimes too and the carb setup they use now with the Z intake is a joke, but still not near as 'funny' as new motors self destructing after 5 miles.
A couple of guys here swear by those 'no-name' motors but recommend you tear the whole thing down and replace things like those bearings with quality ones first.
That's fine for the guys on a really tight budget with plenty of time to spare, I am just not one of them.
I spend maybe 20 minutes prepping a new motor.
I pop the head and side covers, turn the crank a couple revolutions to check the cylinder wall and the 'feel' of it, verify the clutch disengages, port the intake tube, and button it back up with the head slanted forward.
If it is getting stock exhaust I port that pipe too, and I completely replace all stock ignition wiring from magneto to kill button which is time consuming, but still, I just can't see always having to buy parts and break down your bottom end on every new motor before you even use it ya know?
That I guess is the main difference between a hobbyist and a builder.
A hobbyist enjoys the work and usually not totally reliant on their bike for transportation.
A builder like myself and others here realize that initial $25 savings isn't.
And then there are the guys just trying to build something themselves that will be a cheap reliable commuting vehicle.
You don't want to make it a hobby and you don't want to make more.
To you I say start with something good as it is even worse for you, and you will still have plenty of challenges just keeping it running well ;-}
I suspect the "quality control" is far too random to make such assertions regardless of "brand name" KC, there's very little to go on beyond what folks favor... and what caused them to favor that "brand" in the first place is rarely known for certain, even what was once good may not always be so. The forum has always been filled with both success & failures but what "brand" has never been a constant.
For example, the highest mileage motor I have is a "generic" with over 10,000 miles on it. It's beginning to show signs of it's age with somewhat reduced compression & the chrome liner is beginning to flake (below ring travel oddly) - but it's my "ol' faithful" and just refuses to quit, never asking more from me than fuel... yet my shortest lived engine was a Grubee & yep - it ate it's lower bearings at 'bout 4000 miles. My latest engine is another "generic" and while it's too soon to report on reliability, I hafta say the castings are so much better than the Grubee's it's a night & day difference, the cooling fins didn't need straightening, there were no pits or flash ridges & the ports were the cleanest I've ever seen in one of these things (it's also the strongest, but that's more random chance I suspect heh);
Grubee;
Generic;
You've mentioned both "hobbyists" and "builders" - yet as both a builder & a commuter I've found when ya open the box & later, when the miles rack up it really doesn't matter, ALL of these el'cheapo lil kit engines have one thing in common & that's random chance. If you want to spend extra to get quality, spend the extra and get quality, like a decent clone such as Lifan or real quality like Honda, Subaru etc. - but don't bother expecting quality out of these kits regardless of how much extra you pay up front or what "brand" it may be. If you want one of these things to be the "best" then you're going to hafta go through it regardless.
I'm really not trying to say one is better than the other, that the generics are better than branded engines or vice versa, but that no matter the sticker on the side (or lack thereof) - ya buys yer ticket & takes yer chances. What more can you expect for an engine that costs $100 or less? Their low cost simplicity is their charm after all lol
For example, the highest mileage motor I have is a "generic" with over 10,000 miles on it. It's beginning to show signs of it's age with somewhat reduced compression & the chrome liner is beginning to flake (below ring travel oddly) - but it's my "ol' faithful" and just refuses to quit, never asking more from me than fuel... yet my shortest lived engine was a Grubee & yep - it ate it's lower bearings at 'bout 4000 miles. My latest engine is another "generic" and while it's too soon to report on reliability, I hafta say the castings are so much better than the Grubee's it's a night & day difference, the cooling fins didn't need straightening, there were no pits or flash ridges & the ports were the cleanest I've ever seen in one of these things (it's also the strongest, but that's more random chance I suspect heh);
Grubee;
Generic;
You've mentioned both "hobbyists" and "builders" - yet as both a builder & a commuter I've found when ya open the box & later, when the miles rack up it really doesn't matter, ALL of these el'cheapo lil kit engines have one thing in common & that's random chance. If you want to spend extra to get quality, spend the extra and get quality, like a decent clone such as Lifan or real quality like Honda, Subaru etc. - but don't bother expecting quality out of these kits regardless of how much extra you pay up front or what "brand" it may be. If you want one of these things to be the "best" then you're going to hafta go through it regardless.
I'm really not trying to say one is better than the other, that the generics are better than branded engines or vice versa, but that no matter the sticker on the side (or lack thereof) - ya buys yer ticket & takes yer chances. What more can you expect for an engine that costs $100 or less? Their low cost simplicity is their charm after all lol
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KC, I didn't say I had motor problems on BGF kits I said they have corrected the problems. Mine was with wrong parts recieved on a order, I placed a order for a few parts and got a cdi instead of a fuel tank cap. I e-mailed him to get a return number and on the same e-mail I ask about the angled clutch arm like comes on the pk-80, after he got the cdi back he sent me my fuel tank cap and the postage it cost me to send it plus the clutch arm I asked about. I know things happen for whatever reason but he didn't have to sent me the clutch arm.
Well cool Greg, we all like good news stories, especially if it involves a free bonus right?
You do have a valid point BA, most anything you get like these kits with cheap labor is a crap shoot.
Is all it takes is one worker hung over from too much Saki the night before (or at lunch) to do a poor job somewhere and THAT is where quality control comes in.
That QA guy has quota's I'm sure, and he may have partied with that hung over worker the night before too and is in no better shape to do his job right than the other guy.
My only point was for me knocking out a higher end new customer bike or two a week it just makes more sense to me to bet on a known winner even if it is a few bucks more.
Don Grube did pretty much set the bar, he is retired now so who knows what may have happened at the YuanDong Gasoline Engine Co he commissioned to make his Grubee kits, but until I see different I'm good with them.
You do have a valid point BA, most anything you get like these kits with cheap labor is a crap shoot.
Is all it takes is one worker hung over from too much Saki the night before (or at lunch) to do a poor job somewhere and THAT is where quality control comes in.
That QA guy has quota's I'm sure, and he may have partied with that hung over worker the night before too and is in no better shape to do his job right than the other guy.
My only point was for me knocking out a higher end new customer bike or two a week it just makes more sense to me to bet on a known winner even if it is a few bucks more.
Don Grube did pretty much set the bar, he is retired now so who knows what may have happened at the YuanDong Gasoline Engine Co he commissioned to make his Grubee kits, but until I see different I'm good with them.
I have the same problem I think. I havn't had my engine started yet..the bike is built. With the the plug out the engine it will turn and function fine but when I put the plug in, the rear wheel will lock up and skid when I let the clutch out fighting compression of the engine????? If you get an answer let me know. I believe I am so close to getting a functioning ride thanx Ken
