Ben1098

You need to do some checks before pulling the electrics. Resistance test of stator 3 Ph "Y" connection...3 heavy wires coming out...all the same color. The 3 windings have common connection at the center.....just like a Y. Measure the resistance from A to B.......B to C.......C to A. None are marked....you label them (in any order you want) with a marker on the pigtail connector.. Resistance will be under 1 ohm and most meters don't start at "zero" when the test leads are shorted. If your meter starts at say 2.3 ohm with the leads shorted.....expect a reading around 2.8 between pairs at tested leads. Check for Shorted stator windings (A B C) to ground......go to your highest resistance scale.....should read OPEN. VOLTAGE Live test....motor running at idle.....Meter to AC VOLTS. Voltage output (Leg to Leg to Leg) should be in the 30 VAC to 50 Vac (at idle). Increase throttle to half speed.......expect a higher output voltage....say 80 Vac. Be careful as this can really ruin your pants. CURRENT Load test......motor at idle. Using a 120 V "banned" 60W incandescent light bulb for the load, connect to the A-B, B-C, C-A terminals on the pigtail. light should glow.....bump up idle-----brighter. You cam blow (over voltage) the light bulb if you go too high on the Rs. If the above tests are good.....and you stated a new voltage regulator-----you need to check for the Regulator wiring connections. +12 Vdc lead from the battery. Use a test light with a 12 v bulb. I changed one over with a old Chevy dome light (these get hot...remember how the snow would melt off the roof if the door lock iced up and the door stayed "open"). OR make one for a 2 A load from a brake light bulb ----1156/1157 bulb with a socket and pig tail leads will work. Connect one lead to the Neg battery lead for this test. Check the test light circuit by probing the other lead to the + battery post.....bright. Move to the Regulator + output (heavy RED wire) Move the test lead to battery connection at Regulator....bright again.....HOT side wiring is good. GROUND lead from battery. Same as above but connect to the Battery POS terminal this time. Tap the NEG terminal....bright. Tap to the frame/motor case......bright. Move the test lead to the Regulator Neg (BLK) terminal.....should be bright.

What is the problem you are chasing? Charging systems are pretty well cut and dried. Does the motor turn over and run AOK other than the battery going down?

Check the spark plug. Tells the fuel air mixture ratio. Tan color is what you want. A fouled plug....dark and or sooty will blow out (not spark) under heavy ignition energy requirement such as acceleration. Example was late night bed roll traveling H-D Sporty rider who wanted to "impress" me (sitting on a V65 Honda---V4 of grunt) while waiting on him so I could pull out after he went by. Yellow headlight......his regulator has croaked.....battery getting low on minimum ignition voltage level. Predictable cough stumble, and misfire instead of hearing his shorty pipes go by. Tailed him waiting for the death knoll. 6 miles later on a gradual uphill 3/8 mile long hill......he puked.....Naturally, I slowed for him to pull over and land so he could see with my headlight.......then give him a 1st gear 60MPH redline header romp. Now, that is what is what it should sound like. Gone. Lots of info in the above short story. Weak ignition will run ad idle but fail under load. Fouled spark plug. Ignition wiring rubbing on sharp metal edge and a partial insulation failure.....will only corona (ring of fire) under load. Fuel air mix.....BOTH a right mixture and lean mixture will foul a plug. Rich is obvious. Lean mix gives a misfire and UNBURNED fuel to wet down the plug and then fail. Mice.....remove air intake plumbing to give free air at the carb inlet. Check air box and all plumbing for mouse house. Fuel pump diaphragm getting hard....low fuel level in the carb bowl. Test bottle of gas for this test. Last...............bad pump gas...getting bad here over non-national gas station buyouts. My favorite station (always good gas for old Ford gas tractor and Grasshopper). Station bought out.....didn't know. Bought 8 cans of junk premium 93 and when used, the Grasshopper run OK for about a minute. Switched on the deck and died....hard to restart....pulled back to shed and drained slop.

I did a still frame of the little blue flash around 35/38 sec.......that is a problem......to get this, you have 2 problems going on. 1. Intake valve leaking or open-----bent (timing wrong and dinged the piston) or no valve clearance. Leak down test and listen for air whistle. 2. Intake leak in the casting area after the carb intake air boot. The lean air mixture "spit" will also cause the faster idle speed. Recheck the ign timing with the copper wire "feeler depth gauge" TDC piston location. Check that the cam lobes are pointed down-----valves closed and not on overlap and then paint dot the cam index point at 12 o'clock......the dimple is under the metal tab covering the flyweights. I posted a detailed instructions in an earlier post about the paint the cam trick. Recheck the valve clearance. Ensure you are not on the decompression pin for the exhaust valve adjustment.......rotate the flyweights to retract the decompression pin. The BLUE FLASH. Visual. By the size of the blue flash it has to be easy to spot.

Massimo badged HiSun clones has the diodehiding deep inside the wiring harness. Pass side of the machine, radiator side of the firewall. Look for a thick harness bundle run toward the pass side then turns downward.......the diode is DEEP inside the lump of cable going down.....were the wire color changes from the brn-??? IGN ON (HOT) to the black-red tracer going to the switch. AIN"T WORTH IT. Jump from the IGN ON HOT to the blk-red wire.....If you DO want the snuffer diode, insert at the new joint but have the diode band on the blk-red wire

If the new boot is a good fit and function, buy...... Cheaper than engine rebuild if you use on dusty trails. The boot might be petrified anyways. Down side is there might have been different jetting and/or a different spring constant----the stiffness of compressing the spring. The diaphragm slide spring selection is a calibration of spring stiffness, length, and the needle hanging out of the bottom of the slide. The slide position (air flow and fuel from the main jet) = engine RPM.... is determined by the difference in air pressures vs the spring pushing it back closed. These stupid "I need the more speed" wantabe racers have problems with the carb hop up kits like race and full race for crotch rockets-----which literally fouls the plugs when just idle cruising the WHIP. If the air boot modification changes the runability, simply disconnect and and plug---most noticeable when the air filter is starting to get clogged----restricted......changes the designed pressure difference at the slide porting. Try and see.

OFF....both the small tube and the bigger atom vent tube stay open. The tube out of the bottom of the carb fuel bowl is smaller in diameter. That is the gasoline overflow drain for the bowl. Look at the bowl's other side bottom and you might find a screw head, OR a boss pad that COULD be drilled-tapped for the screw. EPA restrictions and/or bean counters deleted the function. This screw (with a tapered end) lets gas will drain from the bowl when cracked open. The bowl drain hose should be open. The external nipple the hose is connected to goes inside the carb to an open ended vertical brass tube. Think of a standing drain pipe for a lake overflow. Function is to keep a flooding carb from filling to the point where raw gasoline runs into the engine cylinder----wash down. The atom vent hose bottom is an open drain. TRICK--------squirt some oil into the hose bottom but now fill to the "T". Blow excess for just a coating that keeps bugs from becoming a squatter. Q. for you. Picture is framed too low. You routed the atm vent thru the air boot molded mounting.......DID YOU FIND A SPOT to connect to WHERE THERE IS FILTERED AIR?

Open drain for dust and water to get in. High water will get sucked in by manifold vacuum if a bug calls the other end home. The vent inside the carb goes directly to the bowl. Water sits on the bottom, jets cannot flow with higher viscosity water and DEAD.

The T hose would be the CV carb's atmospheric vent. The problem with the open ended hose is bugs and dust. Bugs build nests and block off the vent. Dust ingestion is bad for the engine. Older motorcycles would have the open end routed to the INSIDE of the air box and it's own little filter. Yamaha 750/920 Virago vents went to a pair frame mounted steel tubes......open ended.......wasps loved these open ended tubes under the steering head.. Test hose assy by removing the tube at the carb (between the CV slide and the intake horn). Blow shop air thru the just removed tube and it should flow out both the ends. Install a clean tube to the carb and mouth blow air into the tube. You should have no resistance down to the carb bowl and and if blown hard enough, you can bubble gasoline up thru the fuel jets. Function......the fuel bowl has fuel sucked up thru the pilot jet (idle), main jet, and the fuel enrichment (choke cable on the left in the picture. For the fuel to flow, a pressure difference is required.......intake creates a vacuum relative to the bowl's ambient air pressure. Also, the CV carb needs the pressure difference to open the slide against the spring. For funnys, put your finger over the hose nipple and see how the engine stumbles. Now, I see on the air intake rubber tube it has a molded push in tube mount....very close to the end of the tube in your photo. Check around the air box......there might be a hose connector to connect to.

Compression release not lowering the fuel-air mix pressure. Start T/S with removing the spark plug. Put back on the boot and ground the threads away from the open plug hole. Crank over......if it cranks without stalling, the compression release is the culprit. Next, you need to remove both the valve adj lids and the round side of head cover for the cam gear. Rotate the crank and bring the piston to TDC....use a bare copper wire thru the plug hole to feel the TDC highest position of the piston dome. NOTE: there are 2 TWO TDC positions on a 4 stroke engine. OVERLAP.....Exhaust valve just closing and the Intake vale just opening. This not the one you want to mark the cam gear. Rotate the crank a full 360 deg and recheck the valves.......Both should be closed with the cam lobes facing away from the rocker slipper pads. White paint the top 12 o'clock position tooth. Next, check the intake and exhaust valves rockers for the spec clearance. Now for the good part.....the compression release cam within the cam center bore. I did a post a couple months back: T/S a no start with spark that ended up being the wrong Delphi ECM module....timing off by 90 deg. Find this series of posts and it explains the compression release mini cam......the small dime sized disk with the flyweights "pin coupled" at the very center of the cam gear face outside. In a nut shell, rotate the mini cam disk.... Sling weights moved out against the springs tension. The mini cam pushes up an internal pin against the exhaust rocker thus holding the exhaust valve for a short time to bleed off some compression and then the starter can spin over the motor. Things that go wrong: 1. Valve adjustment wrong. Rotate the crank/cam slightly off the pin or hand rotate the weights out to lower the pin and now be able to adjust the valve clearance. Now to check the operation of the decompression release pin rubbing the exhaust rocker. Rotate the crank backwards a couple of teeth on the cam gear. Rotate forward and watch the exhaust rocker. The rocker should hold the exhaust valve slightly open and then snap closed as the pin rotates past the rocker slipper pad. Repeat the reverse rotation and this time rotate the flyweights out to unload the pin.....the rocker should not snap back and have the spec clearance. 2. If the pin did not do anything....as in no compression release......you might have the "pin grove" gouged out of the slipper pad. The rocker shaft needs to be removed with a slide hammer. Check the rocker compression slipper pad....small tab vs. the much wider cam lobe slipper pad for inspection. The gouged out stripe will be obvious.

COMMENT that Reverse works fine..........no bog down as in it revs up ok? See rev limiter posts to bypass at the ECM.......MC DOCTOR has good drawings.

This SERIES snubber diode is to BLOCK the reverse EMF (voltage spike) created when the power is interupted by the thermo fan switch (current stops and the magnetic field of the DC motor collapses). In industrial applications with the control voltage circuits using 24 VDC, the relays will have a SHUNT snubber diode across the coil relay terminals (cathode on the + 24 v terminal and the anode to the - side..........that is put in backwards. The PLC's electronic driver switch, hates to have a back hit from the relay coils turn off (- spike components of the waveform) EMF spike. 120 VAC control voltage circuits relays do not require the diode (would fry on power up). A good visual example is to take an old style Ignition coil and feed 12 Vdc to the + post with and the - or gnd post tied to the - side. Coils were actually 6-8 V and the resistance wire in the harness (GM) or the Chrysler ballast block dropped the voltage to 6 V. Touch and remove the +12 v feed wire....notice the reverse voltage arc flash.....better yet, for a shocking example of what NOT TO DO is grab a good ground and touch the bare wire end of the feed when opening the circuit....the hole in your finger tip will grow back. The magnetic field from the current flow is stored energy........cut the current flow.....the energy has to go somewhere (other than to the high voltage side of the coil. That is why points burn up with a pit and a mound. The size of the capacitor (condenser) is "matched" to the ignition coils "L". The capacitor value size above or below the "ideal match" value will result in the deposit (triangle mound) to be on the base contact or the movable arm contact. The worst thing to do to an old points ignition motor.....TUNE UP. New points and condenser. If the points had little deposit transfer, the capacitor was a good match.......long point service life......only to be thrown away and a new RANDOM value capacitor installed THAT NIGHT NOT BE A GOOD MATCH. Time to quit.

Surprise answer. The units are Yamaha Rhino clones. Yamaha put in a SERIES DIODE SNUBBER........ready for this.......inside the wiring harness. The Massimo 500 units have this diode on the passenger side wiring harness trunk line about half way down the vertical run of the wrapped harness bundle (buried inside the bundle to boot).....along with a wire color change at the diode. Let's make it easy here!!!!!!!!! Not worth digging and cutting the wrap for the diode. Feed is the ignition switch ON lead. When the diode OPENS, the circuit end at the diode. I would tie a wire to the IGN switch ON lug, fuse with a inline 10 A, and then to the itty bitty red/blk wire. Do this jack leg fix and then jumper the fan thermo switch to test....and don't look back.

Quick test. Sounds like the fuel pump is not keeping up with demand. After the 30 sec or so run time, and starts to die, give it a wiff of starter fluid and see if it recovers........fuel starved. Key OFF wait 5 sec or so....Key ON only------no start position. The fuel pump is turned on for about 5 sec to PRIME/PRESSURIZE fuel rail.....signal is from the ECM.......wait it out for time out......then start. Listen for the short prime time running. Start.....ECM should now keep the fuel pump full time. Put a test light on the pump connector (clamp to Gnd) and check for 12v. Then reverse the clamp connector from Ground to a hot +12v.....you can now check for a good ground at the connector.

HS800.....should be HS500. See Motorcycle Doctor store....has several units for the HiSun 500. While you are talking, confirm the flywheel P/N also. Talk about going 20 steps backwards...............been there as we usually ended up with the dogs after $$$$$$$$$$$$$$$$ wasted and they did NOT usually get the "good" parts back as there are no returns on electrical. My personal best was a Honda 350 ATV. Dead IGNITION. 3 H shops, 1 Independent. Shotgun parts. Had thick folder. From Chicago area. Drove down and stood in line a busy (pulled up front) Sat AM. Seen ALL parts for the IGN replaced shop WO parts list. Clue: Asked what he used it for. IDNR food plots. OH! Took clip lead and meter to his PU. T/S in the bed......first guess at the sales counter was right. Run. Boss didn't even know I left. He was charged for 7 minutes. MY take on the whole story...............exhaust cam wear and low compression was the initial killer. CHOW.....hope you finally win. BEN