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| Thread ID: 82079 | 2007-08-15 08:57:00 | Scooter Issues | roddy_boy (4115) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 581347 | 2007-08-16 05:07:00 | Hi all, I recently replaced the clutch hub which had completely sheared in half . The engine loses all power when I try and accelerate . TIA . Is the clutch slipping? |
joemac (9739) | ||
| 581348 | 2007-08-16 05:55:00 | If the clutch was slipping the engine would rev up. Trevor :) |
Trev (427) | ||
| 581349 | 2007-08-16 06:08:00 | 2-strokes need proper backpressure from the exhaust system to work correctly. Proper resistance from the air filter is necessary to get the right air/fuel mixture. A good spark at the right time is essential. Lack of power on acceleration "usually" indicates a fuel problem. If it has reed valves, they might be damaged. If everything is right, it will work. ;) Joe: The motors on some very cheap Chinese generators are straight "Chinese copies" of Honda industrial motors. Some people buy the generators to use the engine parts on genuine Hondas. |
Graham L (2) | ||
| 581350 | 2007-08-16 08:03:00 | Crikey I hope I haven't completely shat the thing. I haven't had a look at anything today, too busy hitting the beers at the pub. While I was using it without the gasket, it chewed through the petrol really bloody fast. I have no means to do a compression test, will the rings be visibly damaged if I were to pull the motor apart? I'm trying to do this all at home without the cost of getting a mechanic involved, so will have a look tomorrow when I'm in a more sober state of mind. |
roddy_boy (4115) | ||
| 581351 | 2007-08-16 08:07:00 | Also to add, it revs fine and wheel spins when lifted off ground, will go to full throttle. However when there's resistance, (ie when I'm sitting on it) that's when it'll cark it. If that helps with the diagnosis at all. | roddy_boy (4115) | ||
| 581352 | 2007-08-17 02:35:00 | I honestly don't suspect the timing is messed up . . . as it's usually set by a woodruff key into the flywheel/mainshaft, where the magnets are located for the magneto to fire the plug . The woodruff could be sheared . . . good ol' Chinese crappy alloys . There MAY also be a set of points inside the flywheel, and that's much more likely to be worn out . . . possibly retarding the timing and making the engine very weak . However, if this engine is a cheap-o copy of a Honda, then they use a non-points system . . . like a capacitive discharge ignition that just depends on the reversal of the magnetic flow as the magnet(s) pass over and then away from the induction coil, triggering the ignition . Go simple first . . . what has changed is the first thing to ask . Do the plug change . . I have seen 2-cycles with poor quality oil that can mask the spark so bad with deposits and ash that the engine won't run under load, but revs freely and can idle pretty good . I don't really suspect the exhaust could clog up as quickly as you said these symptoms came on . A baffle inside the muffler may have moved and plugged up the pipe, but not likely . Fresh gas? Correct mixture if it's not oil-injected? Real 2-cycle oil and not just something you had laying around? Pedestrian stuck in air intake? How does the engine sound? Is it laboring or whizzing freely? Is the exhaust manifold glowing red? Is it badly discolored? (These usually indicate late ignition timing or fuel with too much octane rating . ) I once checked one out that the owner's kid had put brake fluid in . It cherried up the header pipe and seized the piston in short time . |
SurferJoe46 (51) | ||
| 581353 | 2007-08-17 06:58:00 | Do the plug change..I have seen 2-cycles with poor quality oil that can mask the spark so bad with deposits and ash that the engine won't run under load, but revs freely and can idle pretty good. Hi Joe, thanks for the in-depth post. I will change the spark plug this weekend. I don't really suspect the exhaust could clog up as quickly as you said these symptoms came on. A baffle inside the muffler may have moved and plugged up the pipe, but not likely. Yeah I don't think this is likely the case either, everything seemed in good order when I put the new gasket on. Fresh gas? Correct mixture if it's not oil-injected? Real 2-cycle oil and not just something you had laying around? Pedestrian stuck in air intake? Yeah new gas etc, it chewed through a tank really quickly when the exhaust was leaking. Got proper oil etc. How does the engine sound? Is it laboring or whizzing freely? It actually sounds really healthy at idle, and when it's rev'd up with no load on it. It just dies as if there is no air intake when it's trying to haul me around. Revs drop and it carks it. Is the exhaust manifold glowing red? Is it badly discolored? (These usually indicate late ignition timing or fuel with too much octane rating.) I once checked one out that the owner's kid had put brake fluid in. It cherried up the header pipe and seized the piston in short time. Not glowing or discoloured. |
roddy_boy (4115) | ||
| 581354 | 2007-08-17 13:47:00 | It's a Chinese model there there would be your problem I'm trying to do this all at home without the cost of getting a mechanic involved, cheaper to buy a new one, and mechanics don't like them as they are too dodgy Also to add, it revs fine and wheel spins when lifted off ground, will go to full throttle. However when there's resistance, (ie when I'm sitting on it) that's when it'll cark it. If that helps with the diagnosis at all. oh, what mix are you running it at. i'd bet money that's you problem: i got a 50cc pocket rocket (www.trademe.co.nz) for 250 bucks, and after a whole host of other disasters i then got those symptoms too: a talked to a friend with a kawasaki kx85 (www.trademe.co.nz) and he said that 16:1 was the best he'd ever done for it. turns out that despite the manual saying to run 25:1, 16:1 is bloody brilliant (pay to keep the throttle open to stop the exhaust blocking, or clean it) do try, and the best part is the extra oil offers better engine protection and cooling. but being chinese crap, expect problems; it may be better to fork out for a yamaha scooter or even a suzuki fxr150 (commuter/learner/sport bike) |
motorbyclist (188) | ||
| 581355 | 2007-08-17 20:00:00 | Dont listen to bull**** about oil mix it should be manufacturers specification anything else would be stupid. I have OMC outboard which runs 100:1 tedheath |
tedheath (537) | ||
| 581356 | 2007-08-18 01:33:00 | Dont listen to bull**** about oil mix it should be manufacturers specification anything else would be stupid. I have OMC outboard which runs 100:1 tedheath OK..guys...this needs a little light on the subject...and I'll try to keep it short as usual. OIL and fuel pre-mix engines require the right ratios as designated by the manufacturer. You cannot use regular engine oil even though your twice-removed aunt Shirley's husband's nephew did it in '55. Oil for four cycle engines is just for lubrication with various additives for purposes that I shall not go into now. Two-cycle engines actually need to burn the oil after it has lubricated the bearings and piston/rings. Two-cycle oils are designed to not leave an ash-y residue or gum up the exhaust system either. Some 2-cycle oils are designed to be run at 16:1. 32:1, 50:1, 100: 200:1. Adding more oil, although it may seem like a good idea actually leans out the fuel:air ration, making the engine run hotter and possibly burn up because there's too much oxygen in the combustion chamber trying to remove aluminum and metals from the internal parts. Piston hole-ing is common as are splash deposits on the internal sparkplug insulator, making the plug not fire under load but instead the spark gets bled off not igniting the fuel. Wrong oil, bad oil mix, dead fuel, bad plug(s), plugged air intake or plugged exhaust are all things that can be corrected easily. A hole in a piston, scored pistons and rings lose compression...loss of power results. Metal splashed plug electrodes make the engine run poorly. Just go back to square one... fresh fuel... good 2-cycle oil...and make sure it's oil designed for air-cooled engines! There is no such animal as a 2-cycle oil that works in both air-and water-cooled engines!... and a new plug in the right heat range with the correct reach... and then report back what you get...OK? |
SurferJoe46 (51) | ||
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