Pure_Michigan

I bought this old three wheeler that I found in a barn. It looked pretty rough, but I have it running now and functioning. With the switch set to "run" and the key in the "on" position the electric starter does not work when I push the starter button, However, if I cross the solenoid it will work and it will start the engine - so I know the starter motor is good and it works. Now, it gets a little mysterious. When the engine is running, AND the headlight is on high beam, the electric starter will engage when the starter button is pushed.....When its already running! (when the headlight is off or on "low" the starter button does nothing, only when running and in high beam will you hear the starter motor zing when you push the starter button) So, I know the button actually works, but only after the engine is already running and the high beam is on! So to recap: with the key on, the starter button does nothing. crossing the solenoid will make the starter work, and after the engine is running the starter will work with the button! Has anyone else had this problem? Can anyone point me in the right direction on solving this one? Thanks!

Hello All. I just joined yesterday. Great site! I have been riding for much of my life, but never before had a three wheeler. I found this one in an old barn. Some old guy owned it and when he passed his son was tasked with getting rid of some things so I picked it up for $100.00. Didnt know if it even ran, but the engine turned over with a pull so I took a chance. After emptying and cleaning the gas tank and changing the oil, it actually started after several pulls! I am now in the process of repairing or replacing old frozen up parts like the brakes and several cables. So far it runs good and Ive driven it through all the gears with no problems. Seems like a good buy so far. Ok, enough about the ATC, this is supposed to be about me. Im a relatively old man and Ive been working on engines, cars, bikes, etc. pretty much since I was able to pick up a wrench. I really enjoy diagnosing and solving mechanical issues. Presently I work in an engine assembly plant in Dundee, Michigan. I am a supplier quality resident engineer there. Ive been married for 34 years and have 3 sons, who are all grown and moved away. Ok, how am I doing so far? I am looking forward to communicating with other riders on this forum.

I know this is an older post and you probably figured it out by now, but backfiring could be a timing issue or valve adjustment issue.

Remove the battery cables and use a tester to check continuity between the two cables. There should not be any continuity when the bike is off. If there is continuity, then there is a short somewhere. While checking continuity with the tester, at the same time begin removing fuses until continuity stops. That is the circuit that is shorting the battery. Now that you have narrowed your search to that particular circuit, Then it is a matter of tracing the wires of that circuit until you find the short.

Because it idles when you plug the vacuum line, it is exactly that - a vacuum leak. Check the valve that the vacuum line plugs in to. It is allowing air to flow directly through it. Probably a bad valve.

What will make it leak? Well unfortunately, possibly a poorly done rebuilt upper half! Oil is getting into the combustion chambers which causes the smoke. Could be the head gasket was not installed properly, or the head deck had some debris between the gasket and the head or block. Also could be the piston rings were not aligned properly allowing oil to get by. Also check for the presence of, and the proper installation of the valve seals. Oil can get by those too and drain into the combustion chambers. Probably not what you wanted to hear, but smoke is caused from oil in the combustion chamber. These are three ways it could get there. Also, this is probably a dumb question, but I assume you are not putting oil in the gas like you would for a 2 stroke engine.

He said it is getting spark, so I dont think its the coil unless the spark is very weak. But even a weak spark should ignite the fuel. If its getting gas and spark, that of course is whats needed to start. Try some Ether to see if it will at least try to fire. Another thing to check is compression. Pull the plug(s) and check it. The down and dirty way is to put your finger in the spark plug hole and turn the engine over. It should build enough pressure to make a loud hissing sound when your finger is removed at top dead center on the compression stroke. If there is no compression, or very little, Maybe a valve is stuck open or a a timing mechanism is broken or malfunctioning. I dont know the Yamaha warrior, whether its two cycle or 4. If the warrior is a 2 cycle, then forget the valves sticking part.