The Engine Starting Blues
- Thread starter TheSereneOutsider
- Start date
If you are talking about walking along side the bike, releasing the clutch and the wheel locks up and skids, that SHOULD happen. You will need some weight on the bike and some momentum to overcome the compression in the motor and get her to turn over....
If the plug is too long an extra head gasket or a spark plug washer would fix it, but as mentioned it should be hard to get the motor to turn over when engaged.
Another thing you mentioned is the sudden lack of any exhaust, that could well be a plugged exhaust pipe from running way too much 2-stroke oil to gas mix, ever hear of the old 'potato in the tail pipe' trick?
Take the tailpipe off and try starting it without one.
A handy 'tool' to have is a spray can of 'engine starter fluid'.
Take off the air cleaner, open the choke and throttle and spray some right into the carb throat and then IMMEDIATELY try to start it. That stuff evaporate in a hurry so don't dilly dally.
If she fires, runs for a few seconds and dies you have fuel issues.
FUEL TIP:
Though you could probably get one of these motors to run on Kerosene or even diesel fuel for a ways if you had to, don't start out that way.
I like to eliminate fuel as ever being the cause of a problem by simply using premium gas and good 2-stroke oil mixed 25:1 for a new motor, 32:1 once broken in, and I make double sure I keep it clean, fresh and free of debris.
Going back a page in this topic....
One other note about 'Brand Name' motors, when I talk about Grubee's I don't mean any Grubee, I mean specifically the Skyhawk motors not those startfire and other models they quit making back in 2010 as that has been my experience is all.
Like fuel, on a new build I just want to minimize the chance of some given part not performing as expected due to initial defect even if I am seemingly 'throwing money away'.
I'd say 95% of my builds have started right up and run, and when one didn't it wasn't because it was missing frigg'n crank bearings or something like that, and it wasn't because of something as silly as crap gas ya know?
A new builder will inevitably have a problem and have to trouble shoot it.
I just recommend you at least always be thinking about what usually can be a problem as you build it and checking it as you go.
You will have a much better chance your build will fire right up, but if not you will still have a huge head start on your troubleshooting the likely problem.
In short, an extra $20 and an hour checking things as build can save you days of frustration ;-}
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I seen this today and just had to share it in this topic.
Women just don't get us and our toys ;-}
Women just don't get us and our toys ;-}
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I just bought a BGF 80/66cc brand new motor myself. The other motor I had the back mounting bolt broke off inside the motor case, so I just bought another one until I can get it out. So going back to KCvale point, I had the same problem. Mounted and connected everything back up using the new motor. Running a 16:1 (maybe richer?), the engine would not start. I replaced the spark plug with a NGK B6hs and it started right up. Rode it for about 15 mins and everything was fine. Alot of smoke coming out of the exhaust though. Waited for a little bit and was gonna go for another ride, but it wouldnt start this time. It would sputter and feel like it would want to spark and go but nothing. So, I took the air filter off and the exhaust pipe and sprayed some starter fluid into the carb. Jumped on the bike and it started right up (died due to idle issues but started never the less). So I put the exhaust back on and it still started up. After a little bit later, tried to ride again but no start. Took the exhaust off and sprayed it out and a bunch of gunk came out.
So, where I stand right now is no start, but tomorrow I am going to change out the fuel and go with a leaner mixture. Clean out the carb and hopefully that does the trick.
Does anybody agree with the steps taken here? Just asking cause I really want to get this bike going again.
I usually run 20:1 mix for break-in at least 100 miles, then 100 miles of 24:1 and then finally 32:1 (thats just my routine). Some people recommend you use 24:1 for break-in, which I think is ok as well, 16:1 is really oily for sure.
I'm wondering if you had turned the fuel valve off while it was sitting? (before the ride when it didn't start?) Sometimes leaving the fuel valve on can lead to flooding...
I think you are on the right track with what you plan to do, I would probably pull and clean the plug again too, and turn the motor over a few times with the plug removed to flush out the cylinder. (make sure there is no flame or spark near the spark plug hole to ignite fuel that may come out)
Not a lot to add, these guys have covered most. One thing, if your carb is mounted at an angle even if you turn off the gas at the tank it could be leaking the gas in the bowl into the engine. So I'd check the float adjustment also.
You are on the right track I think.
What you need to visualize however is that the carb intake does not go directly into the cylinder, it goes down through the crankcase first and then back up.
That's why you have to put oil in the gas, that oil is what lubes your lower end.
The thing is if your carb is always dripping fuel into the crankcase it fills up, hence all the gunk. That's a float bowl level adjustment.
Shut off the fuel, pull the plug, exhaust and carb, let out the clutch and pedal it up the street and back to blow all the crap out if in doubt. Been there, done that, and it was an instant fix and after a carb float adjustment the problem was gone for good.
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I highlighted your BGF replacement motor choice for a reason, if you buy the cheapest thing for sale it's cheap for a reason and it ain't profit, it's materials.
Just as a side note about motor kits, gasbike.net has sales for most every US holiday and this 4th of July it's $25 off 66cc SKyhawks, the coupon code is J46625 limit one. I have two coming for $173.56 each delivered on separate orders, what does one of those BGF's cost delivered?
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But back to fixing what you have...
Once you get the gunk of the crankcase you can try just resetting it up the way I do which of course like everyone else just my preference and not necessarily the best.
I only use premium gas. I mix it 25:1 non-synthetic 2-stroke oil for 2 tanks, 32:1 with synthetic 2-stroke oil thereafter.
I often just test ride a new bike around the block a couple of times and then just let it sit and idle for half an hour, shut it off and let it cool half an hour, and repeat a few times. That takes the pain out of break-in.
If I use a stock 1 prong plug I gap it at .032, for those 3 prong ones I just make sure all 3 prongs are back far enough, but when I want performance I use an Iridium plug, it is the only item under $10 you can buy that you can actually feel the performance increase with besides good gas and a good mix.
I hope that helps.
RL, while you have the carb off remove the intake and spark plug. Then roll the bike with the clutch out and watch the piston through the intake port, you will see the piston skirt as it clears the port. I have a bgf48cc that the piston skirt did not clear but about 3/4 of the port, I did the piston skirt mod. found in the high performance section to correct this flaw. As KC said sometimes spending a little more at first pays off in the end.
I am all for someone that can take a weed whipper or old lawn mower engine and fab it on to a bike, that takes some creativity and a some mechanical skill and no matter how it ends up looking the thing runs and you have a new toy to play with!
If you actually really need to build yourself some reliable transportation because you need to rely on it for your only transportation that is another story.
I only put out a couple of new bikes a week this time of year but a good 90% of those customers want just that, something reliable and they come to me because I just don't compromise on quality.
That's not a sales pitch, it's the way I build, when everyone gives up on quality I'll find something else to do before I start buying Ebay engines and Huffy bikes.
I hope we helped you get your bike running but if you fall into that Need It For Reliable Transportation group the best I can do is sum up all my advice in 4 words.
Don't Start With Crap!
Sorry it took me so long to reply to all of you, but I want to thank all of you who have put in your input. And very good input I might add. So, after sitting down and just thinking for a bit. All I needed to do (lol, yeah this is me shaking my head) was change out the spark plug and hook up a new CDI. It started right up after that and I have been riding like crazy for the past couple of weeks. I dont know but I think my old CDI just didnt have enough power along with the old spark plug to give fire to this new engine. The BGF engine is OK at best, for the money anyways. I paid $75 for it, but next time, yeah, I am going with a higher end engine. Oh and by the way, I dont even have this engine mounted right. I bought a universal mount from SBP and just now got it so tomorrow I am stripping everything down and remounting it and adding the slant intake pipe as well. Thank you again everyone and RIDE HARD! 