Yet another mixture thread, or...? (Starting problems)

To clean out the exhaust/muffler, grab a spray can of Brake Cleaner from your local auto supply.. I usually throw some kitty litter in a jar or something to catch the run-off so I don't have a mess where I did it. Assuming we're talking about the 49/66cc 'stock' muffler here, you can also undo the 10mm nut on the end and slide it apart to clean out any oily deposits. If you do that, check the holes drilled in the internal pipe for manufacturing waste (I've seen everything from clean and nice to something that might have been dragged through the metal-shavings bin on the way to being boxed up) and clean them out with a file or drill bit if needed.

Now, having just sold a nicely broken in bike to someone who then came back to me with "My friend said I should do this and that etc" I might be a little.. touchy.. on this point. In my opinion, I built it, I broke it in, I know what I'm talking about. His friend does a good job of sitting around getting wasted and talking sh*t.

Your friend should know better after having built "a couple dozen" of these. The mix advice you were given is probably (again, in MY opinion) some of the worst you could have gotten.

Switch to 32 or 40:1 and change/clean the plug.
16:1 is good for nothing but reducing warranty claims the first few weeks.
The chinese factories don't care HOW it runs, as long as it runs more than 30days....
If I had a dollar for ever time I had to say this....I'd own a Vincent Black Shadow.

2door said:

Clean or replace your spark plug, check the muffler to make sure it isn't clogged and inspect the exhaust port on the cylinder. Mix a new batch of fuel and mix it at 32:1, drain what is in your tank now and dump in your new mix.
Get back to us with the results.

Oh, and tell your friend to log on here and do some reading from builders with a lot of experience, years in fact, with these little Chinese engines. He might change his mind.

Tom

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Well said Tom and I have to completely agree , I used to have the exact issues described by teratoma and was using a 16:1 mix ,some friendly advice by you guys has me change up to a 32:1 mix , my motor never misses a beat , takes 10-15 seconds to warm up and as such reaches wot after this short time perfectly, never again will I use the recommended syrup mix and will stick with 32:1

No excess drips from the exhaust and the motor doesn't have that somewhat unpleasant 2 stroke smell

We have oils with determind flash points, at which are more clean and free of carbon deposites etc. A proper clean burn.

Here is some forum stickies. http://motorbicycling.com/showthread.php?t=24873

http://motorbicycling.com/showthread.php?t=305

Wanna say from my understanding. Too much oil can fool some one with their plug reading somtimes?
16 to one will lean out a air fuel mix as there is a little orfice the gas has to push through ''jets''. Resulting in less fuel from the fuel being thicker and the gas being deluted with oil.
However the flash point of the oil is heavier and the bike will soot up running with less power IME. You will get deposites in your motor and plug.

You want Air cooled two stroke oil. Not a water craft kind as flash points are designed differantly. Water cooled motors run cooler. From everything I have learned.


Now wanna say good oil at the manufacture's recommendation is a place to start . If one says 50 to one going 42 to one is nothing like 16 to one lol.

All this rymes with proper jetting. Then the engine will develop good power and run clean!

2door said:

Ditto, Goat.
Those of us who are weird and strange and mix @ 100:1 can tell you all about jetting to match your oil content.
It's confusing to newbies and they have to stop and realize what adding or subtracting oil from the ratio does to the fuel/air mix.
It's just another facet of 2 stroke fun to be learned over time.

Tom

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Right on right on right on......!

Turning the fuel valve to the off position is like an 'insurance policy'. If the float, needle, and seat function as they should, your carb won't know the difference between 'off' and 'on' when the engine isn't running. If you do have a slight/major problem, you won't flood your engine with fuel mix. You won't run fuel mix onto your garage floor. You won't possibly explode your house when those fumes reach the hot water tank's pilot light.

Pretty cheap for an 'insurance policy'!!

Im not gonna bash anyone here but I can say that judging from the advice you say you been getting there is one of two things going on here.... either your "mentors" ars screwing around with you... or they for the most part dont have a clue what they are talking about, right now as you read this post you are in the presence of many people who have 10-20-30-40+ years of experience in some cases with many types of engines and other mechanics in general that aint gonna yank your chain and BS you on this stuff so based on what you have said thus far I'd say quit listening to the "mentors" and use good ole common ( but not so common anymore horse sense) and refer to this forum for correct info on what ails you with your bike because so far everything your buds have told you is flat out wrong plain and simple, not bashing your buds here but shooting straight from the shoulder and just telling it like it is.

Best wishes and I hope the new mix will resolve the issues you been having.

Map

Teratoma.. sorry, didn't intend to "bash" your mentor. However in my opinion the advice you have received so far is not the best.

As for shutting off the fuel.. As xseler said, if the float valve in the carb works right it shouldn't matter.. I've forgotten to turn the fuel off on a bike more often than a I care to admit to myself, and to date have only had a problem once. If the float valve lets anything through you have the potential for fuel to drip from the carb, or to flood the motor. Either way you have excess fuel vapour which is not good in a contained space. If the engine floods (as happened to me), you have to pull the plug and turn the motor over to clear it, which can be a messy process.

Teratoma said:

No no you guys are fine - I'm not offended. I'm the one most likely to go off on them - I'm a bit pissed and I just meant I didn't want to take the thread in that direction.

I've already decided I'm not going to ask my roommate for any more help. He's dismissive of everything I've relayed to him from here, yet has no answers himself.

So no apologies necessary fellas! Your advice has been invaluable and I'm very glad to be here!

Cheers!

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Thank you for your understanding and I can tell you straight up I wish we could get more new members with such a good attitude and outlook, my hat is off to you and anything I can tell you that I know for a fact is true .... you got it and if I dont know there are several other excellent more knowledgable people on here which you have already heard from some here in this thread that can and will be more than happy to help with solid advice to someone like yourself that has such a great attitude....

Welcome

Map

That's great now ride safe and enjoy....!

Map

Good to hear your problem is solved. 16:1 oil ratio is fine for break in (about four tankfuls) to help lube the rings & chrome plated cylinder bore, but once the rings seat, 16:1 is overkill. I prefer to err on the side of caution with a dash of Marvel Mystery oil on top of 32:1 two cycle mix. Spark plugs are cheaper & easier to replace than rings & bearings. But my final ratio is probibly closer to 30:1, and it works for me. There are some here who swear up & down they burn 100:1 all day every day, but they also burn the real expensive synthetic oils. I cannot find a store here locally that sells it so I run the generic stuff for lawn equipment.

Burning a fat oil mix makes the fuel lazy, or rather it slows the burn rate, ideal for a fresh motor to minimize compression blow by and aid break in. By the time you have gone through 4 tankfuls you should have traveled around 200 miles, at which time you can use half the oil as before. If our motors were crafted in Germany or Japan, our cylinder bores would be coated with nickalsil, but they aren't. Instead, they are made by the Chinese, who are masters of slashing costs by using cheaper materials, hence our cylinders are chrome plated, which is softer & less durable, hence the need for a richer oil ratio.

Again, congrats for finding a solution for your problem. If any more come up, know that there is centuries of accumulated experience with these specific engines from hundreds of forum users right here on this site. Many of us are eager & willing to lend advice providing you don't act like a jerk. A lot of us have already gone through what you are right now and can tell you how we overcame those difficulties.