Star Vstar Dragstar 650 Maintenance and Troubleshooting Series





The collection of XVS650 Maintenance and troubleshooting Procedures are all included below.







Yamaha Star 650 Carburetor Remove Clean Rebuild Reinstall Sync - Part 1 of 2

In a previous video I discussed the possibility of cleaning the jets on this bike without removing the carb in certain conditions where they get plugged due to ethanol.  In most cases there are issues where the carbs must be removed for a complete break-down and rebuild.  This video begins with the removal of components from the bike required to remove the carbs from the bike.  This also includes the emptying of the take of any remaining gasoline into a canister.

     Basically with the removal of the gas tank, the carb is exposed to work can begin in and around the carb to detach components from it.  This includes the air filter assembly , hoses and air-box.  The choke and throttle cables, electrical connections,  and fuel-line.

     Loosening the carb off of the manifold is all that is required to unseal them by gently rocking them and then pulling up. They can be lifted up and out of the bike. The manifold ports and inspected and then stuffed with clean paper towels to stop contamination.

     With this the carbs are moved to the cleaning table for inspection and its already apparent that one slide is binding.  The separation of the carb begins by removing the brackets.  Working on one carb at a time, complete disassembly is accomplished, each part is inspected for damage and dirt.

**NOTE as I was working on AC this week I referred to the Emulsion tube as an Orifice tube***

     On this carb there was a definite corruption on the lower end, which will require a more intense cleaning.  With everything stripped, the cleaning begins, one piece at a time the O ring had to be replaced on the bowl for the solenoid. It was solid.

     Every passage was cleaned out and checked for flow with carb cleaner.  When it was shown to be clean and flowing good, it was all blown out on the compressor, after which, assembly will begin as demonstrated.

     A test is done to ensure air tight integrity of the float bowl needle seal.

The second carb, reassembly and testing continues in the second video.




Yamaha Star 650 Carburetor Remove Clean Rebuild Reinstall Sync - Part 2 of 2

Continuing in the second half of this series, the second carb is now disassembled, this one has some minor differences such as idle speed adjustment, however upon opening this carb was found to be much cleaner inside as compared to the first.  It will still be completely disassembled and cleaned like the first, it just wont be as difficult.

   Once the carb is cleaned and reassembled, it is time to bring both carbs back together.  I note an important mistake I made in the video and corrected on a spring between the throttle linkages and balancing adjustment that I had done accidentally earlier and then fixed.  A quick discussion worth having about the solenoids which throw errors because they are expensive and easy to fix so measurements are taken to show what they look like when working and how an open is repaired. Also a check of TPS is conducted as well.


   At this point the carb was reassembled back onto the bike with each connection reconnected exactly opposite as removed.  Once the system was closed up fuel was added with an affixed funnel allowing the pump to purge the air until the carbs were filled to leaks could be checked for. Also checking up to for flooding from a stuck float.

    The next Phase has the air-box and attached hardware all the way through to the air filter installed back onto the bike.  We throw on the tank right quick add a little gas to give it a test run.  I realize I should have used the pump to purge the old gas in the system, but it was not terrible so I would just let it burn through.

   Satisfied with the initial run of the bike I let it cool down so that the rest of the assembly can be completed. Once the assembly is completed, the bike is again brought to full temperature so that the carbs can be balanced.

   After the bike was balanced and throttle response was tested. The boss lady took the bike for a test drive, having checked the brakes, oil  and added air into the tires.  I too took it for my own test drive on the gopro.  Happy with the performance, the project is brought to an end.






Yamaha Star 650 Maintenance - Oil Change With Filter

In this video I narrate as my wife conducts the oil and filter change procedure on the Star / Vstar / Dragstar / XVS / 650.  Though I do explain my reasoning as to why I do not first turn on a bike that has been sitting for a week right before I'm about to dump the oil, your choice.

Note that I would have preferred a small 17mm spanner to open the nut below but I could not find it and went with a crows foot as shown in the video.

The filter cover O ring should be inspected and replaced if necessary.  If you don't know the last replacement, replace it.

Refilling the oil is a two person job unless you have a big stand on level ground.

I use Yamalube 10w40. Check with your local Yamaha dealer if you are not sure of the proper oil weight.




Yamaha Star 650 Valve Adjustment - Checking  and Adjusting PART 1 of 2

Today we will be doing the inspection and adjustment of the valve lash on a Star 650, also known as a Vstar 650 or Dragstar 650, depending on where you live.  This is an important, labor intensive, and often overlooked critical maintenance item that must be performed on any motor with solid lifters.  There must be a prescribed amount of clearance and the margins are small, very small.

  An opportune time to do this is any such occasion that the carbs are removed, such as a carb cleaning or rebuild.  The 650, as opposed to the 1100 still requires much more faux chrome removal even after that just to get to the tappet covers.  Consider this when you think how much your mechanic charges per hour to do this job.  Its not a quick job.  It can't possibly cheap. Maybe someone could tell me though.

  Even with the chrome covers removed, and one ignition coil, each cylinder has its own side cover for the cam to be removed allowing for a particular dot to be aligned to a point on the head.  This dot moving when the engine turns through yet two more covers removed to being this into position.  This having to line up and corresponding to the correct marking on the crank through the inspection hole, depending on the cylinder.

  The final test of this alignment is the wiggling of the tappet, there should be audible play as whey wiggle ever so slightly up and down. If not,  you either messed up, or they are really in a bad way.  Confirming this, and as luck would have it, three of my four were on the outer limits of acceptability.  This means they were good. But I like them in the middle. So, adjust them I did.  This involved the usual technique with a feeler gauge, a hex key and a box wrench. Lock nut is 10 ft/lbs

  Satisfied with the new clearance, I clean the tappet cover, mating surface and put the cover back on. No need to keep it off and risk contamination.  The screws are 7 ft/lbs.  On the exhaust values, paper towel should be used under them before opening as some oil will leak out.  This is especially true for the front exhaust value.  The measurement is one value less than the first gauge that doesn't fit.

INTAKE        .004in     .102mm
EXHAUST    .006in     .150mm             

  Finishing the front cylinder tappets brings an end to part one.  Part two continues with the rear cylinder and reassembly.




Yamaha Star 650 Valve Adjustment - Checking  and Adjusting PART 2 of 2

  We continue here with the inspection and adjustment of the valve lash on a Star 650, also known as a Vstar 650 or Dragstar 650, depending on where you live.  Having just finished the front exhaust value, the inspection cover for the cam is closed after both the cover and mating surfaces are cleaned and the O ring inspected.  This, as well, torques to 7.5 ft/lbs.  

  The process would then continue to the rear cylinder again having to remove the cam cover for the rear and rotate the engine, this time to the TI mark.  On this side, one can see the dot on the cam as the engine is rotated making it somewhat easier.  Aside from this, the adjustment on the valves for the rear remains identical if not slightly easier on the exhaust side than that of the front.

  Having completed the rear adjustment, all chrome pieces are first washed with dish detergent and then using windex and chrome polish, dressed to a shine.  Before installing them however, the spark plugs have miles of room for installation and should be added first.  Make sure as the covers are installed that the pretty hex screws are used on the top covers; don't make the same mistake I did.

  With all of the covers back on, be sure to re-add the hose clip for the breather, and then remount the rear ignition coil.  A final cleaning to remove fingerprints removes all work evidence. A successful job awaiting a carb reinstallation.






Yamaha Star 650 Carburetor Test & Adjustments - Floats, TPS, Heaters, Solenoids, PMS, Leaks Part 1

Today begins the first in a two part series where we go into specific detain with regard to specific testing of the Star 650 carburetor and its components to ensure that it is working within operating parameters.  This is not a rebuild video. I have made those already. This could be considered a post rebuild exercise to determine good working order before installation.  Another thing to consider is the screws that had to be torn up in order to take the carb apart.  The original screws are terrible!!!

The first task is a trip to Ace Hardware where the original screws will be swapped out for better quality hex screws for both the carb and the air box and associated housing.  Though not exhaustive I came up with:

2X M4 .70x20
2X M4 .70x25
2X M4 .80x10
2X M4 .80x12
2X M4 .70x14
8x M4 .70x various

These are swapped out on the carbs, pipes and airbox before I continue.

All of the required parts and tools are gathered for this project before we begin, its better than stopping to hunt for stuff mid-test.  Amongst these would also be a rebuild kit.

The first test will be blowing air into the fuel line and turning the carbs over to see if it is blocked.  A failure of this test would mean immediate attention to the float needles and or seats to resolve this issue.  Though fine here we assume everything fails and replace everything later.

Next, the bowl is marked for the positions where the fuel level should be using the calipers and a razor blade to leave light marks as demonstrated.  That would be 8mm below the line. and .5mm above and below that line.

Its worth pointing out that the carbs are not level in the bike when the bike is level, they are cantered to the low side 13 degrees, so a structure is assembled to pitch the carbs 13 degrees for the level testing.  This is critical.  With the carbs in position we set up the second test which is the hose and funnel on a scaffold filled with gas to see if the level holds.  This proves out the float needles as liquid tight.

With that next test passed, we move to the float level hight test.  using the translucent hose the bowl drain is opened to reveal the level within the carb.  Mine are adjusted higher, but demonstrates how the position can be measured.  I conduct this on both carbs. We can see the level on mine are the same on both.

In the next video, the float adjustments will be done as well as all of the fixes, repairs and testing of the carbs to address all possible issues.







Yamaha Star 650 Carburetor Test & Adjustments - Floats, TPS, Heaters, Solenoids, PMS, Leaks Part 2


We continue with the second video in this two part series. Here we will look at the carbs as if all sorts of problems were found so each issue can be addressed. The first step being to drain out the whole system through the bowls back into a gas can so that the fuel line can be detached and the bowl cover removed.

The first step will be the replacement of the float needle and seat from the carb with the ones from the kit.  My kit required swapping the screen from the old one after cleaning to the new seat before installing.   I further take this opportunity to demonstrate float level height adjustment before reintroducing the float into the carb.

I then assume that the bowl cover seal is also bad, though it probably isn't far off from bad anyway, and demonstrate replacing that as well before closing up the float cover. This would be the time to do float measurements and leak rechecks.

Having moved past the floats I move onto the heaters and their resistance testing, though noting that the readings off of the cable can be deceiving as two are in parallel, so its best to check each one for about 8 ohms, and then continuity through the harness.  The solenoids should be about 12 ohms.  When they break, put a 12 ohm resistor off the cable connection to ground and forget about them.

TPS is just a spring loaded pot.  The first measurement across is the total resistance, the next measurement tests the sweep.  It will never start at 0 ohms installed in the bike.  So long as its between 650 and 750 ohms in the closed position its ok.

A requirement for a deep ultrasonic cleaning allows for a demonstration of TPS removal as well as the drilling out of the PMS needle plug.  An account is made of the turns of the PMS needle to full seat and recorded. The carb is submerged in solution to about 60degC simple green and distilled water until it comes to temperature and then two sessions of twenty minutes with the oscillation.  After this the carb is cleaned in distilled water, blown out with compressed air and reassembled.

The PMS needle is screwed in to full seat and then dialed out to the appropriate turns.  This is followed by the TPS which is installed and then calibrated to 700ohms at closed plates with the meter as shown in the video.


Having completed all tasks, the other pieces for idle are re-added to the carb. Also the wire looms are added for the cables. This carb is now tested and ready for installation into the bike.








Yamaha Star 650 Fuel System Testing and Troubleshooting  - From The Fuel Tank to the Carbs


In todays video we will be going through the complete fuel system from beginning to end to identify problems from within the system that might be causing issues with the bike.  This demonstration is conducted with the tank removed for ease of viewing and conducting the demo.

  In the first half of this exercise the assumption is that the delivery is hindered or corrupted by foreign matter requiring testing of flow from the tank and requiring possible parts replacement at the fuel valve and onward towards the furl filter as well.  As a follow on to this, if flow could be achieved an instruction of purging the system of old gas is demonstrated so that all of the old gas is not re-introduced into the carbs.

  The second half of this video deals with the normal sounds one hears when the key is heard and run switch actuated, this, which can point towards a possible fuse issue if an expected sound is not heard leads us to check all of the fuses in the fuse box.  If its determined that all of those fuses are good, a further check of all electronics can be made by running gas right to the carbs and starting the bike that way, a good test to rule out the switches, relays and ignitor.

  This doesn't fully rule out the pump or electric to the pump though, because if all of that worked, we should see the 12vdc at the pump connections on startup, so we gain access to the pump connector to check both the resistance of the pump as well as the expected voltage.  If the resistance of the pump is infinite or short, well, its gonna have to be replaced.  If there is no battery voltage when power is applied, then there is an electrical issue to trace.

  If its determined to be the pump, we demonstrate the removal of the pump from the bike as a unit replacement for resolution of the problem.





Yamaha Star 650 Ignition Testing and Troubleshooting  - From The Battery to the Spark 

There is also a pickup coil check to be done next this is between 182-222 ohms, this is pass fail. If it fails, well, this is a different video altogether, but at least points to the problem.  Following this a good test if to measure battery voltage to the back of the coils as demonstrated.

This brings us to a test section where we want to make sure there is no gas in the carbs, so we run the starter until the carb bowls are empty, and/or drain the bowls.   Using the spark gap test tool mentioned before, we can check for spark outside the engine by connecting this from the wire to the cooling fin and running the starter.  Such a test confirms good ignition.


Still no spark with this good, this points towards the plugs, so its time to pull the plugs for inspection and gap measurement or replacement.  The standard gap is .035.  A plug test I use though not recommended is to ground the plug to the cooling fin to see if they work.




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