1. Dead Battery/Stator 2. Engine knocks below 2500 rpm 3. Starter won’t turn, full of oil 4. Fuel coming out the overflows 5. The “Vision Stumble” 6. Rear cylinder misfire 7. Bike dies when put in gear 8. Fuel tank & petcock leaks 9. Engine “hunts” at idle, hard to start or stalls 10. Misc electrical problems #1 Dead battery/stator Aside from lack of normal maintenance, this problem typically manifests itself after riding, the bike fails to restart, but will take a jump. A quick test with a meter shows battery voltage only. (11.5-12.5 Volts) If inspection of the 3 wire connector between the stator & reg/rec shows evidence of melting, then check for continuity between any of the 3 white wires on the stator side of the connector and ground. There should be none. An inspection of the other connector on the reg/rec going to the wire harness should also be done, paying particular attention to the heavy black wire. This wire is the shunt ground and must be in good shape also, or reg/rec damage will result. Download the charging system fault finding chart on the Electrex USA website To accurately diagnose charging system problems, you must start with a fully charged battery. It is strongly suggested that a bad stator or reg/rec be replaced with Electrex units, their quality is far superior to Yamaha’s, for a lot less money. #2 Engine knocks below 2500 rpm A knocking or rapping sound at idle that goes away at higher rpm’s is an indication that the starter clutch bolts have loosened. Ignoring this problem will cause damage to the clutch and eventually failure. The reason this happens is that the 3 factory bolts that hold the clutch to the flywheel (rotor) begin to back out of their mounting holes. The solution is to replace the bolts with slightly longer bolts and peen over the exposed threads to prevent them from backing out. Details of the repair can be found here. #3 Starter won’t turn, full of oil The nose of the starter sits in engine oil and contains a seal. This seal is a single lip non-spring design that will leak due to age and wear. Brush damage is common result. The solution is to replace the seal with a double lip, spring seal. Specs and sources for the upgrade seal are available here. Only the stock seal is available from Yamaha. Some members of the ROV Forum also have extras for sale. Complete brush plates are still avalable from the dealer for about $55. Jason Morris in CT also reconditions our stators, contact him at jsmthefix@msn.com #4 Fuel coming out the overflows The cause here is twofold, first dirty carbs can block passages in the carbs, causing a backflow situation, second Float height should be lowered by 2 to 3 mm. It seems that quality control when inserting the drain tubes in these carbs left a lot to be desired, as a result some tubes are shorter than they need to be, causing the carbs to over flow when the floats are set to specs. The addition of an inline fuel filter is a must! I offer a carb reconditioning service for $60 a set, contact me at luckyvision@hotmail.com #5 The “Vision Stumble” Defined as a hesitation or “bog” when the throttle is quickly twisted open. Again this very common problem is now usually related to dirty carbs, & improper adjustment. Again, addition of an inline fuel filter cannot be stressed strongly enough! Originally Yamaha offered a recall on the early 82’s that consisted of replacing the airbox & front carb top with one containing a vacuum operated flapper door, jet changes and lengthening the accelerator pump rod. Most of the early 82’s have been updated, all the later 82’s and 83’s should also have had this upgrade stock. These carbs are very susceptible to any dirt in the system, and many of these bikes have sat for years, allowing the fuel in the carbs to dry and gum up. The solution here is to dip the carbs, thoroughly clean & properly adjust them. After the carbs are clean, follow these steps to help eliminate the stumble: ? Synchronize the carbs for equal vacuum. ? Adjust pilot screws to approx 2.5 front, 4.25 rear from lightly seated. ? Adjust accelerator pump rod to give a full shot for entire throttle travel. Accelerator shot should spray a nice cone pattern between the throttle plate and the wall of the carb. If most of the shot hits one or the other, carefully bend the nozzle as needed. ? Eliminate any vacuum leaks in the system If the previous steps don’t help, or only partially cure the problem, there are 2 more things you can try. The first is to locate the mounting screws for the dashpot that opens the flapper door. You will find that the mounting holes are slotted. Slide the dashpot back until it stops, and tighten the screws. There have been reports that several ROV members have had success epoxying 1 or 2 nickels onto the flapper door, causing it to open later and improving response. #6 Rear cylinder misfire If after ruling out coils, plugs and wires by swapping components, the problem still persists, try disconnecting the black wire with the yellow stripe at the TCI 6 wire connector. This wire is connected to the rev limiter in the tach, and tells the TCI to kill the rear cylinder until a lower rpm is reached. Problems with the rev limiter can cause the misfire #7 Bike dies when put in gear Side stand switch has failed or shorted to ground. Disconnect the switch and repair or replace as needed. Trouble shooting the safety relay may be needed. #8 Fuel tank & petcock leaks Often the lower corners of the fuel tank develop pinhole leaks because these are the low spots in the tank, water and sediment collect here and eventually cause rust holes. Generally these holes are easy to seal and a coating of POR-15 should be applied to the inside of the tank to remove any rust, seal and prevent any reoccurrence. After 20 years of use the petcock will often leak as well. While this is not generally a problem if the inlet needles in the carbs are in good shape, it can cause a problem if fuel leaks past the diaphragm in the petcock and enters the crankcase via the vacuum line. A crankcase full of gas would not be a good thing. Fortunately for us a rebuild kit is available from: Cycle-re-cycle part II 2255 E 10th st E-Mail: cycle@crc2onlinecatalog.com Indianapolis, IN 46201 Part# # 2698 $24.95 #9 Engine “hunts” at idle, or stalls at lower RPM Typically the engine idle will rise and fall several hundred rpm over a period lasting from 5 seconds to as long as 45 seconds. The culprit here is usually a leaking YICS canister. Diagnosis and repair info is here #10 Misc electrical problems Many of the Visions problems stem from a history or period of time in the bikes life when the bike has sat idle for several years or was neglected. A common result is an electrical system fraught with gremlins. Very often the solution is to go thru every electrical connector on the bike, one by one, and clean every connection to bright and shinny. Be sure to coat them with a coating of light grease. As tedious as this sounds, it will solve many potential problems before they start, and allow “bonding” time with your bike as well. |