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

[Teratoma]

I dug around on this board for a thread describing the exact symptoms my bike is displaying and came up null - though I am suspecting my fuel/oil ratio to be the culprit.

That being said I'm going to describe the problem as best as I can to see if it sounds familiar to anyone:

The bike/engine are under 4 weeks old. This problem seems to have developed within the last two.

Basically, I have a hard time starting. I have to pedal and pop the clutch several times over several blocks before it'll "start". In quotes because it will start and die a few times after that. Once I get it to idle, I can gradually rev it until it stays running, but it still takes a few minutes after that to "perform".

Once I deal with all of that and the bike is 'warmed up', it *will* perform. I can then stop the engine, and as long as I don't wait too long, it will start right back up and perform just fine. If it cools off again - it's back to the beginning.

I was told by the person who helped me put this together that "you can't use to much oil" and as a result am probably using a richer mixture than even 16:1 - but after reading the forums I know that isn't true. He insists that isn't my problem but I'm asking here; does what I've described sound like it could be anything else?

tl;dr: new bike quickly developed problems starting/performing - but works fine once warmed up.

 

[2door]

Any reading on mixture here should convince you that 16:1 is too much oil. Every kit instruction manual will tell you to mix @16:1 and in almost every case it has been proven to cause problems much like what you are experiencing.
Your spark plug can foul, the muffler can clog and exhaust port restricted by the excess oil in your fuel mix.
The general feeling is that the 16:1 ratio is based on using regular engine oil, not oil formulated for air cooled two stroke engines. Which by the way we highly recommend you use.

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

 

[Teratoma]

Yes, this is pretty much the kind of response I was looking for. Everything you said pretty much tells me that is my issue.

At one point I replaced the spark plug and it seemed to help tremendously at first but then it was the same.

I'm using MasterPro 2-Cycle Sport but in my first couple of tanks used Valvoline Multi-Purpose 2-Cycle.

I didn't mention this, but I have observed absolutely NO LEAKAGE from the muffler. I thought it may be clogged and causing the problem - and that trying to start the mike with the muffler removed would reveal that to be the case, but it still wouldn't start. Now it sounds like that might just be another symptom of the mixture issue.

My friend has built a couple dozen of these - having access to his experience is what finally made me build this - but he can be stubborn. I appreciate the "community knowledge base" myself!

Thanks - I will let you know how it goes.

 

[CTripps]

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.

 

[maniac57]

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.

 

[Henshooter]

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

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

 

[Goat Herder]

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]

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

 

[mapbike]

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

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

 

[Teratoma]

Thanks for the great responses everyone! As I indicated earlier, I was pretty sure my mixture was the problem.

My friend does have the experience - I lived next door to him for years and now we're roommates. I have learned a lot from him - which includes when to get a second opinion, believe me. Especially now.

@Maniac57: at one point last week I did change the plug and noticed a substantial improvement at first, but then the issues returned. This just re-enforces what's being said by everyone else here.

Well said Tom and I have to completely agree , I used to have the exact issues described by teratoma...

This is my favorite response so far - since you had "the exact issues" I described and resolved them easily by changing the mix.

SO. My work is cut out for me this weekend, and I will report back soon. I know that joining this forum was definitely a good choice - thanks again.

Cheers!

 

[Teratoma]

And hey - without turning this into a bashing-session for my "gas-bike mentor", I have another question:

What problems might be caused by leaving the fuel valve in the 'on' position while parked?

The reason I ask is because a certain associate of mine told me that its only purpose was to prevent leakage, and if my bike wasn't leaking gas I should just leave it 'on'.

Well, another associate of mine (who told me his 'mentor' had suggested a 32:1 mixture) said that I would be constantly flooding the carburetor by doing that. Sounds reasonable.

After trying to remember to shut it off ever since - it seems to have made a bit of a difference. Not a substantial difference, but perhaps a noticeable one? Meaning I can start the thing in ONE block as opposed to two or three... Of course I realize the mixture is my main issue - but a carb flooded with syrupy goo would certainly compound the issue, right?

tl;dr: How can I explain to someone why leaving the fuel-valve 'on' is a no-no?

Not worth starting a new thread for - I would've included this in my OP if my other friend had mentioned it sooner.

 

[xseler]

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'!!

 

[mapbike]

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

 

[CTripps]

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.

 

[2door]

I concur. Get in the habit of shutting off the fuel valve when the bike is parked.
Have you ever noticed that almost all motorcycles have fuel shut off valves? They're there for a reason. You might forget to turn it on once or twice and suffer the humiliation of running out of fuel. But no big deal. Most of us have done it a couple of times too. I once pedaled for a block, wondering what was wrong, before I realized that I had forgotten to turn the fuel back on.

I too apologize if I seemed to be bashing your friend/roommate. We simply want you to get the best advice possible. It's why this forum was created and why we'll sometimes poo-poo on bad advice. No offence intended.

Tom

 

[Teratoma]

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!

 

[mapbike]

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!

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

 

[Teratoma]

Thanks for that Map!

And let me just say that Lola and I just got back from one freakin' EPIC ride - and more importantly - PROBLEM SOLVED!!!

I filled the tank with a mixture close to about 40:1 give or take, and went for a 20-or-so mile ride up into the foothills, with a few substantial changes in elevation.

She started right up, and pretty much SCREAMED and PURRED the whole way instead of sputtering or lagging like she's been doing.

Absolutely gorgeous night for a ride - and I'm just giddy that it was such an easy fix!

Thanks to all of you for your help and for welcoming me here.

Much love!

 

[mapbike]

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

Map

 

[SuperDave]

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.