Matt Burr Posted March 3, 2012 Share Posted March 3, 2012 I just bought a yamaha DT-175 as my first bike, it runs great and is a blast to learn on, but I find that as you drive, everything gets dimmer. I had it out today for almost 2 hours, and by the end, the headlight was pretty dim (with it running, dead when turned off) and the turn signals wouldn't work at all. I know it must be producing SOME power because it runs even with the battery dead, but the lights are very dim so it clearly isn't producing enough to keep the battery charged and everything working at full power. Any suggestions? I've never owned or worked on a bike, but have fairly extensive experience in cars, which is where I draw my conclusions from, so I apologize if any of the assumptions I made are wrong. Thanks, Matt. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 3, 2012 Moderator Share Posted March 3, 2012 You say EVERYTHING gets dimmer, need a little bit more here before offering a response. Pop the chassis number so we can check ( minus the last couple of numbers if your worried) up as this sounds like the 12v eleccy start model with a generator, bit more complex. Link to comment Share on other sites More sharing options...
Matt Burr Posted March 3, 2012 Author Share Posted March 3, 2012 it's 6 volt system, kick start (which makes finding bulbs...interesting) Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 3, 2012 Moderator Share Posted March 3, 2012 Ok well your extensive knowledge of cars will be useless here, only joking the mechanical principles apply as my Dad puts it " its only nuts and bolts" but bikes do it differently. For starters there may be not a whole lot wrong with any one part just 30 years of age. First, make sure the battery is OK, i mean proper ok too as it is most likely buggerd. Second check all connectors and earth points, clean them and check they are tight. As a help for duff indicators a electronic relay helps no end with lower rated bulbs. A last consideration, a couple of the lads on here have swapped the electricals (well documented process in the thread) around to run 12v instead of 6. Have a search see what you think it may be a better option. Link to comment Share on other sites More sharing options...
Matt Burr Posted March 3, 2012 Author Share Posted March 3, 2012 The battery is new as of about 2 weeks ago, I've checked the grounds and they seem good, no broken or damaged wires on the outside of the bike, but I Don't actually understand their charging system. Terms like 'stator' might as well be latin for as much as I know about them... Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 3, 2012 Moderator Share Posted March 3, 2012 Ok here goes nothing.... The stator is the stationary part of the charging system. On the stator plate you have some coils, an ignition coil that generates the power for the ig system. As well as the charging coil which on most of the 175's is also the lighting coil. You also have the rotor, look behind your LH (chain side) engine cover and you will see a heavy round unit, this is the rotor. This as the name suggests rotates around the stator and contains a number of magnets. These excite the coils and cause the electical energy to be created. DO NOT use the oldskool removal method of a hammer on the shaft and screwdrivers to pry. You stand a very real chance of damaging the rotor, magnets or crank bearings. All of them if your really lucky. A puller is available from the auction sites for around a tenner VERY worthwhile as it fits most Yams at or around this cc. The electricity thus generated is high frequency AC, this is good if a little awkward. The elecrical energy for the headlight travels via a rather unsophisticated diode to make it DC after a fasion. At the same time via the ig switch this is also connected to the regulator, depending on the model it will be under the seat on the rear muddy or behind the kicker on the frame. This keeps the electrical energy at around 6 volts. The spare goes to the battery and feeds other electricals like your brake lights, indicators etc. With the lights off the same happens but without the lights (amazing huh) and the juice just feeds anciliries and charges the battery. The biggest problem is that motorcycle manufacturers are always after making things as small/light efficient as possible so if the bike needs 300W to power everything then it will generate 310W max. So there is very very little spare. Hence reccomending you check everything. Do you know your way around an electrical test meter for ohms primarily? Link to comment Share on other sites More sharing options...
Matt Burr Posted March 3, 2012 Author Share Posted March 3, 2012 Yeah, I can check for ohms. Also, I know the guy who owned it before me couldn't get the headlight to work, he traced the power wires down and found out it wasn't getting power, so he spliced it into another power wire, I don't really know which one, he just said the headlight wasn't getting power so he spliced it into something that was hot when the key is in 'on'. is it possible that he spliced into something that isn't part of the lighting power system? Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 3, 2012 Moderator Share Posted March 3, 2012 Sounds like it, probably the battery line. Would explain why everything dims together as the headlight is killing the battery you may not even have a proper generator lighting feed. Reving the engine to 5000rpm you should have around 7v at the battery terminals with the lights off. Next, have a look on the LHS of the bike near the neutral switch there should be a conector/connectors (models/bodgers differ) there should/will be a green/yellow wire which should be .30ohms +-10% and a yellow wire which should be .18ohm +-10% when checked using the engine as earth. Link to comment Share on other sites More sharing options...
YPVS TONE Posted March 4, 2012 Share Posted March 4, 2012 Hi Matt If it is only a 6 volt system I think you will find that the lights were designed only to come on with the engine running as they are powered by lighting coils on the stator. With the ignition on and engine off you should have power that works the horn,indicators,brake light and neutral light. If not as cynic say's check connections and earths (plain black wire on Yamaha's) and make sure the main fuse is ok. Link to comment Share on other sites More sharing options...
Matt Burr Posted March 4, 2012 Author Share Posted March 4, 2012 I just read up on this (I.E. I bought a manual) And apparently the headlight DOES run on a separate circuit...AND it AC instead of DC. Guess this just keeps getting more interesting. I'll make a point of trying to rewire the headlight up on the AC circuit tomorrow morning. Link to comment Share on other sites More sharing options...
YPVS TONE Posted March 4, 2012 Share Posted March 4, 2012 Could you tell us what year the bike is or post a picture or as Cynic suggested the first few digits of the engine / frame number. Does it have twin shock rear suspension or monoshock rear end. Link to comment Share on other sites More sharing options...
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