The Mordern Bajaj Chetak Rides One
 
Per Al K:



"When tightening the nut for the rear wheel you tighten it to around 90 ft./lbs. torque. In this case, you are NOT putting any load on the bearings. you are tightened the hub and inner race against a shoulder on the main shaft. The clearance of the main bearing on the rear wheel main shaft of the Bajaj engine is fixed. No matter how loose or tight you make the nut, the bearing clearance will remain the same."   



This is critical as the rear hub nut holds the rear wheel onto the splined drive shaft.  If this hub nut comes loose, there is a good chance that you will strip the drive shaft splines necessitating a major engine repair.  2003 and later models had a slightly larger drive shaft with slightly more robust splines.  This was one of the few changes made after the modern Chetak hit the American roadways, the American riders spent more time at higher speeds placing higher forces on this splined shaft.  The other major change involved a larger CDI as the American riders had the mandatory "head-light on" federal requirement that the 2002 CDI could not keep up with.
 
Only fill the tank to the first ring at the bottom of the filler neck. Look inside you will see that between the bottom ring and the top ring, there is a vent to the emissions system. Ff you overfill, the excess gas goes down that tube to the emission can that is filled with charcoal and once that gets wet it cuts off the air to the tank causing a lock the gas in the tank wont move without air. This causes sputtering, hesitation and rough running; even quitting.

In the early days, riders with this problem resorted to drilling holes in the gas cap to prevent this vacuum lock, but most found the emissions hose easy to disconnect to relieve the lock and learned to keep the gas level below the ring. 

 
This is a procedure that you should read entirely before lifting the first wrench.  To replace the lever you will need to deal with connections at the lever end and at the engine end, so it pays to know in advance what you will encounter.


To replace the clutch lever, you need to remove the single nut from the bottom of the headset on the clutch lever side. Then, using a flat-head screwdriver, unscrew the threaded bolt from the bottom of the headset. You now have to disconnect the cable from the lever. You will need to get down by the enigne and loosen the pinch bolt so you can slide enough cable up to give you spare cable at the lever to disconnect the cable from the lever. Then, be careful as you remove the lever as there are two small washers that will come out with it - one on top and one on the bottom. Save these, as you'll need them! 

This is probably also a good time to replace the cable.  Inspect the cable outer to make sure it's in good shape. Lubricate the new clutch cable using a lube of your preference - grease or chainsaw chain oil  etc (each has proponents and detractors). Thread in your new clutch cable from the headset. Don't connect the cable to anything just yet. 

Now install your new clutch lever. It can be tricky with those little washers, but be persistent and you'll get it. Grease up the clutch lever on both sides and in the bolt hole. Put a washer on each side of the clutch lever and insert the threaded bolt through the bottom of the headset, through the washers and clutch lever, and into the threaded part of the headset. Be very careful with threading the bolt in because it is super easy to strip the threads in the headset (which is a difficult repair). Once you've got the bolt threaded in correctly, thread on the nut and tighten it to the point where it is nice and snug but you can still operate the clutch lever with very little resistance. 

Now put the clutch cable into the retaining hole on the clutch lever. Grease this area well as it sees a lot of movement which causes parts to rub against each other and wear. Pull on the clutch lever from the engine side of the frame and make sure things are working well. Thread the cable properly through the adjuster and clutch actuator arm on the engine side. Attach the pinch bolt behind the clutch actuator arm and adjust the clutch cable to your preference. 

 
The method that works well for getting about the same tension on the shifter cables is to hand tighten the adjuster bolts as much as I can without putting lots of oomph into it. Then I tighten down those lock nuts while trying to not turn the adjuster bolt. The cables are evenly adjusted, which is important so they don't jump out of gear, and there's very little play in the shifter. It goes into each gear pretty smoothly and confidently.
 
The barrel adjuster is only for taking up a limited amount of cable slack. When you run out of adjuster room, turn the barrel adjuster back down to minimum thread, but do not bottom it out. Your clutch cable should now have some slack that needs to be taken out:


Look for the clutch lever on the bottom of the engine. The clutch cable goes to this lever and a bolt type cable clamp. To adjust, you loosen the bolt on the clamp (the right size wrench is in the tool kit that came with the scooter). grab the cable with some pliers and pull the slack out of it, then push the clamp up against the lever. Don't push the lever itself otherwise you will partly disengage the clutch when it is supposed to be fully engaged. Using your own third hand, a third hand tool, or a friend's hand, tighten the bolt. The clutch should be adjusted at this point. Now try riding. If you get that whining sound, and the gear change is more notchy than normal with the lever all the way out, then there is still too much slack. 
 
If clutch cable adjuster bolt/assembly snaps off

It's a right-hand thread, meaning that if you turn is counter-clockwise
(from either end) it will come out.
If there is a portion of the hollow tube extended beyond the casting, you
could saw a slot to accommodate a screwdriver. If you have an "easy out"
that would be perfect for this job, unfortunately most people don't have
one.

Soaking the part first with some penetrating oil and heating the aluminum
casting will help. Do this several times before trying to remove it. If one
end has damaged thread, you do not want to screw these damage thread through
the body, they will damage the internal threads in the aluminum casting.
Because of the hole through the bolt, this part is more fragile than in
appears. When you finally replace the adjuster, don't make the lock nut too
tight.


 
Picture
The Bajaj (and all Vespas) should be transported on their wheels, not on the center or side stand, so that the scooter's shocks and springs absorb any jolts instead of bending the stand or the metal body. Get some flat strap webbing about 3 foot or so longer than the handle bars and tie small bowline loops in each end. Run the webbing strap around the hand grips in a manner that the
loops point to the front and the strap goes direct from hand grip to hand grip.


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If you don't like this homemade web strap, you can buy one as shown in the picture called a Canyon Dancer. 

Put a used scooter tire or car tire at the front of the trailer and use tie downs to pull the front wheel into this spare tire, compressing the front shock/link slightly. The front wheel is going nowhere now.

Use tie downs on each side of the rear (the Bajaj rear seat handgrips are a good location), again compressing the shocks slightly. Now the rear wheel can't go anywhere. Basically your 4 tiedowns should now make a "v" going out from each end of the scooter.

It is ok to leave oil in the scoot as long as it is secure and can not fall onto on the battery side. Before tying the scoot down, all gas should be drained from the gas tank and the bike should then be run to drain all gas out of the carb as well.

You should have no problems if you do the above. I have trailered scoots using this method thousands of miles.

 
From time to time riders encounter symptoms they describe as "fuel starvation."  Essentially, the scooter runs and is rideable but seems to have no power or lose power at higher speeds.  Sometimes this  actually is fuel starvation caused by a vacumm lock created in the gas tank.  Please understand that the Chetak gas tank is not very high above the carboretur so there is very little gravity force to feed the carb,  Almost any blockage or kinking of the fuel feed lines can cause this symptom.  But, there can be many other causes - a bad spark plug cap, a bad CDI, and simple loose ground.  The following list of checks can be performed to rule out various causes:

SPARK

1. Check for a solid ground wire on back of the engine housing, if this ground
wire gets loose, inconsistent electrical performance results.

2. Get the right spark plug:

Champion PL7YC (OEM but impossible to find)
Champion L87YC
Bosch W5BC
Bosch W5BP
NGK BP7HS. (Easiest to find also as it is also used in small yamaha outboards)

3. Try replacing the OEM spark plug cap with an NGK resistor cap, the OEM sparkplug
cap has a history of problems that cause crappy running symptoms identical to
your description. 


4. Replace the CDI, a "New Racing CDI" runs about $14.00. All cdi's do go bad over time.

5. Check the main fuse while you are at it. The bike will run with the fuse
blown but no headlight is usually the one indication that the fuse is blown. I
have dealt with lots of electrical problems related to this.

6. You may want to purchase a spark tester - a inexpensive device that fits
between cap and a ground and shows you a spark for every revolution. Inconsistent of spark

at high speeds could be
caused by 1-4.

FUEL

1. If you ran out of gas immediately before the problems, this could indicate that you

 just sucked every bit of debris and varnish into the fuel tap screen and the carb. 
Clean the carb. Check the color of the float - white is good, brown is probably an indication
 that the float leaks and is sitting in crappy gas all the time. Check all fuel line
connections to the carb and check for kinks in lines. Empty tank and fill with
clean (preferably ethanol free) gas (use fuel stabilizer religiously unless you
run the scoot every day). Blocked carb valve, carb jets, carb ports, or a
sinking carb float can all cause "fuel starvation symptoms." 

2. Test fuel flow from fuel tap to carb. Close the petcock, pull the end of the
line off at the carb, open the petcock and watch for a vigorous flow of fuel
into a can. Move the petcock to the reserve and you should get the same
stream.If it is a small stream it is blocked at the fuel tap and you will need to
pull tap and clean it out.

3. Pull off the evap line from top of tank, blow it out to prevent any blockages
there. At high speeds, this line has been known to cause a vacuum lock in the
gas tank and prevent the gravity fed fuel flow at high speed.

AIR

1. Inspect your filer element, you may find oil in it from when the bike has
been lowered onto the battery side or you may find your missing gas - who knows?
But if there is stuff in there, then poor running will occur.


 
The only fuel filter are small screens attached to the fuel cock assembly:

If you suspect it's crudded up, you have to pull the tank. It's probably more
intimidating sounding than it really is though. There's very little to it.
Remove the small screw from the fuel cock handle, pull off the rubber grommit
around the fuel cock, remove bolts at the top of tank, lift tank up gently while
making sure the fuel cock is coming back through the hole. You should be able to
lift the tank up enough, getting the fuel cock rod out of the body with the fuel
line still attached. Tip the tank toward the back and then disconnect the fuel
line and let it hang. This is obviously best done with a pretty much empty tank.
Typically you would put your fuel cock on reserve and open the carb drain bolt
to let all the gas out. Since your reserve is suspected as not working, you'll
have more gas in the tank than you'd like and may need another method.

With the tank out, the fuel cock can be unscrewed and examined. Check the
screens for crud. The white screen filters do come off but can difficult.

 If you're going through the effort of taking out the tank and cleaning
the fuel cock, clean your tank really well! Take a wire brush and get all the
paint off to the top around the fill hole area (that's what flakes into tanks in
the first place). 

 
Here is the answer I got from Bajaj when I asked them the same
question:

The rim around the headlight is snapped on. Grab is at the bottom
with your fingers and pull forward, it will snap off.

Then unbolt the mirrors, then remove 4 screws from the bottom of the
headset that hold the top 1/2 on. Now you can access the bulb from
the rear of the head light.

You can use a 55 watt in place of the 35 watt. They are available
at automotive stores. Take you old one with you. I'm not sure of
the numerical designation.

Regards,
Tech
www.BajajUSA.com 


The Modern Bajaj Chetak Rides On The Modern Bajaj Chetak Rides On