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auto choke
by: scooter - Nov 12, 2015 11:09:42 GMT -5
Post by scooter on Nov 12, 2015 11:09:42 GMT -5
The enricher on my motomia 150cc has packed up,bI amvon my way to purchase a new one. What size main jet should I fit for high altitude? The difference in air density from sea level and 5,000 ft is about -11%. I'd  you'll end up dropping the jet size between 01 and 05. |
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Post by scooter on Nov 11, 2015 11:54:12 GMT -5
There once was a man from the sticks Who liked to compose limericks But failed at the sport For he wrote them too short Now ain't ain't that a kick in the knicks?  |
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Post by scooter on Nov 11, 2015 11:42:17 GMT -5
Ok, a quick follow up - Before I made photo, i did tryied to adjust A/F screew (hoping this helps). Result had no major effect (as i had an air leak) but i noticed that engine responds in lower/higher RPMS. I did taped it up and the engine did not started. Then tuned-up A/F screew again and managed to start. I can go bit higher in revs but still it goes off. Moto start perfectly and idling ok. Do I need to be super accurate with A/F screew?? no. It's not that critical. |
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Post by scooter on Nov 10, 2015 9:09:21 GMT -5
It could be. Try putting some tape or gasket goo over the cracks and see if your performance is any better. Any air leaks can cause fuel delivery problems, especially at higher RPM.
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Post by scooter on Nov 2, 2015 14:58:16 GMT -5
Does anyone have any info on this scooter, specifically looking for info on the engine and body. It's a 2009 that my buddy bought new. I have worked on it before (mostly just oil changes, tire changes and such), but recently he had an issue with the exhaust, it keeps coming loose and losing the studs from the head. I think we've replaced the studs 4 times now, they seem to be in there good and tight, I even loctited them last time. They lasted for almost a year but now they are gone again. Anyway, he and his wife decided to get rid of it and it landed in my garage haha, so now I'm looking for a solution to the exhaust issue. I would just order a new head, but the scooter is a 170cc and a normal 150cc head won't fit on it (compared it to my other 150cc). I guess if I could find a suitable head, I'd just as well replace it. Otherwise, could I just pull the current head, fit new bolts in and have a shop tack-weld them in place? Thanks for any info / advice. Locknuts, locktite, and you could tie steel wire around them like they do on airplane fasteners. Twist the wire onto one nut, take it around to the other nut and twist it onto that one. Should never come loose, ever. |
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Post by scooter on Oct 31, 2015 2:07:22 GMT -5
Now I think that maybe my exhaust is the culprit... ever since i've put a performance exhaust on this scoot, it seems to come loose at the engine and causes this issue and some backfiring. What I don't understand however, and am hoping someone can fill me in is as to why this causes the issue. it seems that if I remove the exhaust pipe and re-seat it is fine until it comes loose again. since this is EXHAUST how is it that it affects performance??? I could understand if I had an air leak on the intake but am confused... I'm not an engine guy so I'm not that well versed on it... maybe put lock washers on them |
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Post by scooter on Oct 29, 2015 16:39:06 GMT -5
closed circuit
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Post by scooter on Oct 22, 2015 12:16:16 GMT -5
Hey gang, Question for those who have more knowledge about these things than I do. Put a BBK on my bike. its a 2014 taotao 49cc. since the upgrade there has been more difficulty starting the engine. thought it might be the starter or lack of battery power. yesterday i put a new clutch on it and some new slider weights in the variator, and after doing it, the engine would not start. it would turn over half way, but never fully turn the engine over. tried w/ a more powerful battery and same thing. tried a different starter and same thing. took the plug out and the engine would turn over great. the plug was wet, and looked pretty fugly for only being in 1 day. (changed the plug to an ngk iridium the day before this happened). w/ the plug it will only turn over a half turn there is too much compression in the engine! it really doesn't help that the kickstarter doesn't work, so I cannot get the engine to turn fully over. my mechanic buddy says that should fix the issue.. but im not sure how it happened in the first place. from what i read, it sounds like maybe there should have been an thicker or extra gasket on the bottom to decrease the compression. not sure where to go at this point... would like any advice that you guys can offer. my mechanic buddy says that for some reason the engine has been sucking in more fuel than it can burn and thats why the compression is so high. fun facts.. the old plug did not look bad or wet at all.. but a new plug should not be able to change the way the engine is sucking in gas though... If you have a stroker crank then you might need a spacer/gasket between the cylinder and case. |
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Post by scooter on Oct 22, 2015 11:50:44 GMT -5
I did clean the carb. It was really clean when I took it apart, but I disassembled it anyway and cleaned everything with carb cleaner & compressed air through the passages. There really wasn't anything in there. I took the spark plug out & grounded it, and it looks like it has good spark. Is it possible that the emission system with all the hoses and junk would make the scooter act like that. Is it ok to remove that junk and plug it off? If you have compression, spark, and fuel, then it should run without quitting. I'd suspect low fuel supply due to low vacuum pressure or a dirty or failing fuel pump. That's about all I can figure from here. |
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Post by scooter on Oct 22, 2015 11:43:19 GMT -5
Hi guys and gals, I'm still new to the boards. I have a 2011 Peace sports 50cc scooter, that I would really appreciate your help with. The scooter always backfires on deceleration, and dies when taken off the center stand. It has either too high an idle or too low an idle once warmed up. The smog system has been removed. Adjusting the fuel/air mixture screw makes essentially no difference in rpm unless screwed all the way in (clockwise). Here is the work that has been performed thus far: Carb has been completely torn down and cleaned thoroughly. New cdi, stator, solenoid installed, each played with individually so as to verify integrity of each component. Spark plug gapped at .020,.021,.022,.024,.028,.030,.035, and scooter tested to see if each gap setting made a difference. So far, .020 seems to produce the best results. Valve clearance set to .003 for both intake and exhaust, exhaust gasket at muffler/head replaced and tightened new wiring harness installed, new vacuum operated petcock installed. New (keyed) ignition switch, kill switch tests good. No air leaks at intake manifold to carb or head. No air leaks at airbox to carb, vacuum lines replaced, gas lines replaced, fuel filter replaced. Float level adjusted, bowl does fill with fuel. No gas detected in air cleaner. I cannot keep this scooter from backfiring when letting off the throttle from WOT. My current thinking is that SMOG removal = needs 1 size smaller jets = an always rich condition?? = backfiring?? Any help with this would be greatly appreciated. Any thoughts? Sounds like too much air in your exhaust. If you had one of those EGR things on your exhaust pipe, you'd have to seal it off. Maybe check your exhaust nuts and also look for holes or cracks in the muffler if it's old. |
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Post by scooter on Oct 21, 2015 21:28:34 GMT -5
It has spark, fuel, haven't checked compression but sounds like it does when cranking, just wonder if it has enough spark. When I give it throttle past half way it sounds like it's hitting the rev limiter, which it's not, but that's the way it sounds. Sprayed carb cleaner around the intake and all the hoses when it's running and doesn't make any difference in the way it runs. I'd clean the carb. I'd look at the spark and take a wag as to whether I thought it was strong enough. I've seen weak looking ones that worked fine. Check engine ground. I think there are videos on the site on how to actually check your electrical components. Certainly some on youtube. |
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Post by scooter on Oct 21, 2015 18:54:56 GMT -5
i've used 20-50 in bikes for a real long time,,,never had a problem,,,altho it gets really hot here in southern cal,,,,and gear oil is what should be run in the rear gearcase,,,i would not use "engine oil" it is not up to the task Is there 30wt or 10w-40 gear oil? I have seen this recommended in some manuals, but it does not say gear oil or engine oil. It just says oil. What are they referring to? |
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Post by scooter on Oct 21, 2015 18:52:11 GMT -5
Curious if you ever pulled the spark plug right away when it wouldn't start to see if you have spark or not? Use one of these if you like to spend money spark testerThat looks nice. I don't like removing plugs if I don't have to. These scooter engines are so soft that I'm always afraid of stripping threads. Worse, if someone else has already partially stripped them before you work on it. |
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Post by scooter on Oct 21, 2015 18:46:10 GMT -5
2014 Velocity MP150-5. The engine cuts out after half throttle. Sometimes the engine won't start at all without pulling off the fuel line and putting it back on or removing the spark plug and putting it back in. When it does start, the choke doesn't raise the rpm's, but it will idle and run, but when I raise the throttle position over half way, the engine cuts out like I'm turning the switch on and off. It stays running but cuts out. When I drop it below half throttle, it runs normally. This is all being done with the scooter on the center stand, not riding it. It will stay running until I shut it off. After I shut it off, it will not restart unless I mess with the fuel line or spark plug. I have cleaned the carb and adjusted the valves. It started doing this suddenly, was running fine then started slowing and wouldn't go over 20 mph, then when I shut it off it would not restart. When I first pulled the wire off the spark plug, the metal end part of the wire was stuck to the spark plug. It has threads on it and I screwed it back on inside the spark plug boot. Is this possibly the symptom of a coil going bad? I'm a decent mechanic, but this has me baffled. Maybe there is an expert that has some advice. I'd check the plug for spark and examine the plug, check for vacuum leaks, and check compression by feel or sound if you don't have gauges. Of course check the gas and fuel filter for funk or debris. |
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Post by scooter on Oct 21, 2015 18:38:05 GMT -5
Air filter looks great, like brand new. New spark plug installed for testing today. Scooter ran great around the hood. Soon as I hit the open road for testing, same issue, sputtering out. I let it sit for 30 seconds or so and it would get me another 100 yards or so before it sputtered to a stop again. I managed to do that all the way home. I will note, towards the end I Sprayed carb cleaner on the intake side of the carb. It did seem to run a better for a bit but still went back to sputtering to a stop. Here's a pic of the new spark plug after this test session:  Yes. Sounds like a vacuum leak. I assume you have a vac operated fuel pump or petcock. |
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