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Post by czechmate on May 23, 2008 22:04:50 GMT -5
I always learn the hard way. A little bit impatient I was trying to start up my Linhai 300 scooter that was hesitating until the engine got flooded with gas. I checked the oil dip stick and there's definitely gas in the oil. I understand I have to change the oil but do I have to monkey with the spark plug as well? Is there anything else I have to do so I won't damage the engine? Thanks,
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Post by allworld on May 23, 2008 22:34:48 GMT -5
Czechmate How did the gas get into the oil? Is there alot of gas in there?
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Post by rerun2 on May 23, 2008 22:59:27 GMT -5
Flooding the engine should not get gas into your crankcase, unless I am missing something here... I think you would practically have to submerge the engine to do that... wish I could help with that...
As to a flooded engine, there are a couple of ways to deal with it... first and most obvious is to just leave the scooter alone for a while and let evaporation deal with it... that can take some time but is sure fire.
Another way to deal with it is to open the throttle to FULL POWER, then do NOTHING for at least a full minute, then cycle the engine starter for a second, you should get some response from the engine, a chug or so if it does not actually start for you. If it responds at all, try hitting the starter with NO THROTTLE, this should pretty well get things back to a 'normal condition'. It should start at this juncture.
Whatever else is happening, remember that these batteries are small in more than one way, so letting one rest some at times is not a bad idea...
I am sure there are more tricks out there too...
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Post by czechmate on May 23, 2008 23:18:04 GMT -5
Hm... I'm was going to change the oil anyway so no big deal about it. I THINK I got gas in the oil maybe I just... don't know what I'm talking about. I was thinking there's no way for the gas to get to the crank case. So maybe there's no gas in the oil. The scooter will be "resting" for at least another day. I hope it will start then. This all started when I was trying to start up the engine and it was running for a few seconds and then it died. I had to give it some gas to keep it running the next try. You know the rest... It seems that there's something funky and I just don't know what it is. Anyway, this all is so frustrating and I really hope that it'll run so I can finally ride it. Thanks for your input. Nik
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Post by Gary on May 23, 2008 23:29:44 GMT -5
This may be totally irrelevant, but my GY6 150cc scoot was really tough to start (would easily flood out) until I got the valves readjusted. With valves properly set, it starts like a charm.
On the other hand, my 250cc scoot strarts great first time every time, and the valves haven't been touched in 10K kilometers.
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Post by earlwb on May 24, 2008 0:09:37 GMT -5
Patience, let evaporation do its thing. Gasoline evaporates pretty fast. Wait about 5 minutes or so, take a breather to get over being frustrated. Then when you try to start it, if it doesn't quite catch, give it about 1/8 to 1/4 throttle and try again. It should catch and fire up.
What did you do to get gasoline in the oil? As I see it, you had to drown the engine in gasoline and risk getting hydraulic lockup in the cylinder combustion chamber.
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Post by scooterollie on May 24, 2008 7:58:55 GMT -5
Sometimes when the carb. float sticks open, the combustion chamber may be flooded with gas, some of which can work its way down past the rings into the oil. Don't think that is the issue in your case.
If you really think the engine is flooded, remove the spark plug and look at it. If the electrode tip is wet, it was flooded. If so, hold the throttle wide open while you crank the engine a few times, about 10 sec. per time. Then let it set. Allow the plug to dry off. Some folks used to hold a lighted match at the tip of the plug to burn away the gas. It should evap. on its own, though. While the plug is out but connected to the ignition wire, you might want to hold the silver metal side against metal and crank the engine a little to verify that you are getting a spark. Re-install the plug, being careful to catch the threads properly. Don't tighten too hard. Try starting the engine again. Don't twist the throttle. The auto enricher should do the job. If it still won't start, you need to check that the carb. is getting gas.
To verify that the gas pump is working, you will need to remove the left side lower panel under the foot rest. This allows you to see the gas pump and filter. Disconnect the discharge hose from the pump. Hold the hose over a bottle of something to catch the gas. Turn the ignition switch on and the pump should run. I have never had to do this on my Linhai but it should work to tell you whether or not your pump is supplying gas to the carb. The pump should run when the key is switched on. I don't think you need to hit the starter button. If no gas comes out from the hose end, you may have a defective gas pump.
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Post by Andi on May 24, 2008 13:16:03 GMT -5
Sometimes when the carb. float sticks open, the combustion chamber may be flooded with gas, some of which can work its way down past the rings into the oil. Don't think that is the issue in your case. That's about the only way I know the crankcase can get filled with gasoline. I see it on small equipment like generators or industrial equipment, the fuel valve of the tank was left open and during transport the unit shakes up and down and the fuel makes it way past the rings into the crankcase. Great way to clean the inside of the crankcase, which is one way of telling even after the oil (and gas) was drained out. In your case though I doubt that it happened from trying to start the bike even if it was flooding, it would take a good while for the gas to get past the rings, definitely not a few starting attempts. If you really have gas in your fuel you want to make sure to replace it with proper oil before running the engine, as the oil will be to diluted to provide proper lubrication. Furthermore as per your problems keeping the engine running, I don't want to open a can of worms, but I'm getting the feeling that some of the Linhai engined scoots may have an ignition problem. I have a Race 250 and now finally with no spark at the plug, it all started with having to change the sparkplug frequently, after a good long drive the bike wouldn't start the next day, put in a new plug and it started and ran just fine again - 4 plugs in under 400 km and at speed it seemed to bog down, but then ran OK when backing of the throttle. Going from a D8EA to a D7EA seemed to help some and the plug lasted longer, until now I have no spark at all. I suspect its the pick up coil (exciter coil) or the CDI, the ignition coil seems to test to Yamaha specs anyways. I have read a good few problems on here in recent months with the same Linhai engines, complaining on starting problems, flooding, not running good at high speed etc. Some thought it was fuel related and changed and/or added fuel pumps, changed over to an Iridium plug, or changed the CDI and coil altogether, to rectify the problem. Putting it all together I wonder if there is a common denominator? An inherent flaw of one of the ignition components. It brings to mind a bulletin issued by Honda USA for some of the 2004-2005 CBR 1000, which had a problem with the charging system: "American Honda has determined that riding a 2004-2005 CBR1000RR motorcycle in the low rpm range for an extended period of time may cause the ACG to overheat, which causes a short circuit of the stator windings,resulting in insufficient battery charging." Simply, the problem was that the flywheel clearance was to close and the fix was a new flywheel and stator covered under warranty by Honda. Now this is just an example, I'm not saying this is the problem with the Linhai engine, but the point is if Honda can have a problem like this its even more likely on a Chinese scoot and I may just have been lucky ( ) enough to get the worst end of the problem. I'm sure it will be some time yet, if ever before we'll see any bulleting as to problems from any of the Chinese Mfg's. I'm now looking to get a peak voltage adapter for my multimeter to check my pick up coil, CDI and primary coil Voltage and hope to come to a conclusion in identifying the problem. Changing all the ignition components may fix the problem, but doesn't identify the root cause. I'm looking to see if I can sub with Honda parts as they are easily available to me or at least Yamaha parts, which in theory should work as it was cloned form there, the same Chinese parts may just cause the same problem again. Andi
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Post by allworld on May 24, 2008 17:20:04 GMT -5
I have to do a little prep to my scooter( just recieved it last night) and I'm not able to get to it till Monday. I have the same scooter with Linhai engine. I am hopeing that this problem is not a inherent flaw. I will post any difficulties I have that are similar.
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Post by scooterollie on May 24, 2008 19:15:47 GMT -5
You have to remember that it isn't the fault of the Linhai engine if the assembler (company) that bought the engine used substandard electrical components, wiring harnesses, hoses, fuel pumps, etc. The engine won't run if the component parts don't work!!!!! No different with any of the other cheaper Chinese scoots with sub-par components and assembly quality. Just because the engine might be made by Linhai it does not mean that all the other parts associated with it's proper operation came with the engine. A BMW engine in a Pinto would not make the entire product a BMW!
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Post by motomech on May 24, 2008 20:17:51 GMT -5
Motorcycles have the crankcases filled with gas all the time, but a few things have to happen simultaneously. They are; 1]Gravity fed fuel supply. 2]Gas valve left on(manual)or vacuum valve malfunctioning. 3]Float stuck in carb. 4]Intake valve open.
<<<...I have read a good few problems on here in recent months with the same Linhai engines, complaining on starting problems, flooding, not running good at high speed etc... ....Putting it all together I wonder if there is a common denominator? An inherent flaw of one of the ignition components.>>>
I think you are making a bigger deal out of this than it is. Pick-up coils fail in Japanese motorcycles and scooters. In fact, for modern Japanese small engines, they are the most likely "to fail" componate in the ign. system. Next would be the CDI and lastly, the secondary coil. If the Japanese can't make these bits "fail-proof", it's not a surprising the the Chinese items go bad.
<<<...Changing all the ignition components may fix the problem, but doesn't identify the root cause...>>>
If it fixes it, does it really matter why it happened? These parts fail because of slight defects on the manufacturering process. A small fissure in the insulation, a section of the winding that is too thin, something that is brought on by heat and vibration(guessing here, since all these goodies are "hermetically sealed for our protection").
<<<...I'm looking to see if I can sub with Honda parts as they are easily available to me or at least Yamaha parts,...>>>
A quick look at the Majesty 400 parts fiche shows that they do not offer the Pick-up coil as an individual part. You have to buy the stator asm. I couldn't find a fiche for the Linhai electrics at the Parts For Scooter site, but at the Roketa site, it too, was shown as only available as the Stator asm.
The CF Moto 244 pulse generator(as Honda calls it)was $34. Strangely, the genuine Honda part is the same price. You would have to splice into the wires and hope that the mounting bracket is the same. But that seems riskey to me. Roketa lists the Linhai "stator loop" for only $70($200 for the Majesty 400 stator) and if you think it is the pick-up coil, that's the way I would go.
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Post by Andi on May 25, 2008 6:39:03 GMT -5
Hey motomech,
Ignition failures compared to common repair issues are rather rare and therefore are not typically stock items. Besides I was talking about the CDI and coil to exchange for Honda parts if possible. The pick up coil would likely be difficult due to design configuration and I don't know if the majesty coil would even fit on the Linhai.
I don't know about you, but I wouldn't like to exchange the whole ignition system if all I need is one component. Root cause analysis is the most important part of trouble shooting and also the most difficult. The part needing to change isn't always the cause it may just be part of the symptom some other component may have caused it to fail. As with the Honda CBR1000 bulletin, the symptom was stator failure, the cause was the flywheel tolerance. A customers recently came by, asking for help with his 2005 CBR1000, that's why I used the example. He was frustrated as he had the stator changed and rewound many times, but it was always just a temporary fix. I checked with Honda, got the bulletin and ordered the listed parts, problem solved. That was simple and easy as Honda had already determined root cause, but I'm sure it took their engineers some time to analyze the problem, as I'm also sure that they never intended this engineering flaw.
Our technical training manager, a master mechanic having served with the US Navy for 30 years once told me that working on an engine is like surgery, the mechanic is the doctor and the engine is the patient. Why fix the heart if the liver is the problem and why transplant his liver if your patient is an alcoholic and you can't get him to stop drinking, you've fixed nothing ...... root cause analysis.
Andi
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Post by czechmate on May 26, 2008 21:30:06 GMT -5
Guys, Today I tried to start the scooter again and as soon as I touched the starter the engine started and kept running nicely. I really don't know what happened the other day. I know that I panicked and I was trying a little bit too hard to make the engine run. I also changed the oil -there was no sings of fuel in it. Again, in my state of panic I THOUGHT I smelled gas. I adjusted the idle speed again and took it for a short ride. Everything seemed to work the way it should. Thank you all for your input -it is very much appreciated. Nik
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Post by scooterollie on May 26, 2008 22:00:14 GMT -5
Nik, Great news!!! Sometimes a new, dry engine will run a little, stop, run a little, etc. until the fuel feed is continuous. Sounds like you now have proper fuel delivery.
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Post by oldkid on Jun 3, 2008 15:46:11 GMT -5
Nic, The only time my Mainstreet has not started perfectly was once and I think the side kick stand switch was stuck. Scooterollie told me to clean and lube the switch. I cleaned with WD40 and added a little engine oil. It has not happened again. If this happens again you need to check this. I did swap to the Iridium plug but so far have not adjusted any screws on carb. or anything.
Oldkid
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