Maintenance tips - sliders vs rollers, valve adjust, new tires

[mrbios]

Paul, after all my testing the Dr. Pulley Slider Weights at 18 grams are the best compromise, and it will drop the rpm to 7000 rpm at 70-75 mph.  ...
Eric

Eric,

Thanks,  I decided to try with Dr Pulley 19g sliding weights.  I installed them today and road around the block.  The rattling noise I would hear while coasting by parked cars around at 15 mph or faster seems to be gone.  In a little while I will go on the highway.

Question:  when putting the front pulley back on - that is the variator - I saw that the aluminum threads were stripped.  I think I might have done this by powering the nut on with my air impact wrench.  Does it matter?  I could not get the belt out of the way to get started on the splines.  Does the holding tool help with that? 

Thanks,

Paul

[windwheeler]

OUCH!   The spline is VERY important, so important that you have to park the scooter immediately until replaced!!!  I hope you are not talking about the thread on the crank shaft, right?  You are talking about the spline on the face plate pulley, right?

The procedure to get the belt correctly back on requires that you push the other pulley (at the clutch, or "final drive") a bit apart and the belt there a bit down INTO THAT pulley, usually by turning it a bit. that gives you then a bit more length for the front assembly.

Make sure you use before putting all parts/pulleys on the crank shaft a blue = serviceable thread/nut lock like Loctite

In the front you can not use the impact wrench from start; that was your mistake.  You have to use a regular socket wrench to ease the face plate pulley onto the shaft and match the spline at the same time!  This works with tightening and  slow turning at the same time and letting the belt work its way "up" to a larger circumference on the front pulley.

When all is tight, you can use the holding tool and torque to specs, or the Impact wrench shortly until the nut stops moving in relation to the pulley (that you can hold by hand with a strong leather glove). 

Sorry, but what you describe, if you ride the scooter you could damage the crank shaft irreparably and that would mean an engine rebuild, new crank, etc. EXPENSIVE! So DO NOT RIDE the scooter until you have the face plate pulley replaced, only about $27 +shipping... 

[richard1958]

"I agree, I would not replace a belt at 4500 miles.  The wear depends how "hot" the belt gets.  Interstate riding is harder on the belt than just around town with lower speed.  So, I would "inspect and measure it"; belt width should be above 22 mm, and no big signs of rubber shaved off in the casing.  I bet you have none of this.  I changed a belt at 11,500 miles because it started to slip, and that was my former 2005 G/V, and I ride a lot of interstate miles always around/above 70 mph GPS..."

Again thanks for the good advice.  I  inspected my belt and it looks good at this point.  The width which I measured at several points is:  .94 inches = 23.9 mm.   Sorry for the clunky way i did the quote above.  I need to figure out how to do it correctly.

Rich

[mrbios]

Paul, after all my testing the Dr. Pulley Slider Weights at 18 grams are the best compromise, and it will drop the rpm to 7000 rpm at 70-75 mph.  If you have standard roller weights you will see an improvement.  You can go to 20 g Dr. Pulley weights for a bit less rpm "in the middle" but you will loose acceleration.  Your gas mileage depends on that big windshield that is a barn door to push, and yes, I loose also mph and mpg when I have it on it in winter.
Eric

Eric, I installed the Dr. Pulley 19x23mm 19g flat slider weights and the three plastic clips aka guides?.  As you stated the rpms are cut and there is a small decrease in the midrange.  I noticed I never hit 8000 rpms now which is fine with me.  I set a speed record following an suv down a big hill on the highway 87mph indicated and the rpm stayed below 8K.  I probably didn't need to replace the guides so I saved my old ones.  Thanks for the advice!

[windwheeler]

You are welcome!  I am sure you will set more speed records, 87 mph indicated is already pretty good.  Usually 90-92 mph (true 83-84) is as much as one can get out of the engine,  and then it is even with the slider weights turning 8000+ rpm. 

So what was the "stripped aluminum threads" you were talking abbout? 

[mrbios]

You are talking about the spline on the face plate pulley, right?

Yes, just the soft aluminum pulley splines.

The procedure to get the belt correctly back on requires that you push the other pulley (at the clutch, or "final drive") a bit apart and the belt there a bit down INTO THAT pulley, usually by turning it a bit. that gives you then a bit more length for the front assembly.

Thanks, that solves that mystery.

Make sure you use before putting all parts/pulleys on the crank shaft a blue = serviceable thread/nut lock like Loctite

Will do and I have plenty of it.

Updates:
New speed record: 90mph indicated - again down hill on the highway following an suv.  Speed record for me, routine driving / "crusing" for the suv.

I adjusted the valves today and made sure to convert the 0.10mm to 0.004 inches.  I rotated the crank three times to TDC.  Both valves were very tight.  I couldn't get the feeler gauge in until I loosened the lock nut.  After I started the motor the valves make a ticking noise where before they were silent.

Also, I noticed the head gasket is leaking some oil but not too bad.  The nuts on the cam shafts look like they were removed and reinstalled. I bought this scoot with only 2,600 miles from the second owner (they bought it 3 months earlier than I did with 1,600 miles).  They had to have the carb cleaned / rebuilt as it was clogged from sitting with old gas.

I checked the air cleaner - it had the original mfg date of 03/2005 on it.  It was pretty dirty so I brushed it off and plan to replace it in the fall.

I removed and checked the spark plug and it looked great.  I bought a new NGK DP87EA9 at Autozone for $2.50.  The generic 90w gear oil was an amazing $5.99/qt.  I changed out the gear oil.  I poured the old dark gear oil into a mixing bottle and it was low by about 1.5 oz.  It was probably original.  I want to take a compression test but I will need to cut the old plug and weld to use it as an adapter as my gauge is too big. 

Thanks for the advice, I will post pictures when I get a chance.

Paul

[windwheeler]

Paul, if the splines on the aluminum face plate are "compromised" you are playing Russian Roulette driving this scooter.   They are absolutely crucial for the power transfer, and if they "ratchet through" due to 20 HP pulling on them not only will you get stranded, could theoretically even crash (block rear wheel) if the belt entangles, but it also can damage the crank-shaft, belt, etc, and then you need to rebuild the engine with a new crank...  I saw one Kymco G/V where this happened.  I is a quite significant issue you should not ignore, and really not ride the scooter in that condition until fixed.  All I can do is "warn" you, the rest is your decision...

[windwheeler]

As I said before, OEM Kymco valve clearance is 0.10 mm factory recommended setting, but reducing it to 0.07-0.08 mm is no problem, makes no difference in performance and safety, and yes, it is quieter (less ticking noticeable; but a it ticking is OK!).  However, any setting under 0.05 mm is just too tight and also dangerous for the engine in the long-run if they get tighter.  Think about climbing a longer hill or longer time wide open throttle on the interstate...  Too tight will burn valves.

[mrbios]

As I said before, OEM Kymco valve clearance is 0.10 mm factory recommended setting, but reducing it to 0.07-0.08 mm is no problem, ....

Ok, good news.  I went back in there and this time I put feeler gauge blades that were bigger than 0.10mm  I was able to fit as large as ~ 0.17mm.  So I readjusted things and came up with exactly 0.10mm (0.004") on the intake and (0.12mm for the exhaust).  Now things are nice an quite with only a tiny almost in audible slight tick.  I decided to go with 0.12mm for the exhaust because I know the exhaust will tighten up over time. 

I installed a new NGK DPR7EA9 ($2.50 at Autozone).  The old plug looked really good with 10,400 mi on it.  I put some anti-seize compound on the threads gapped it to 1.0mm.  I going to do the fuel filter next.  It is brown.  I also tossed in a few oz of fuel injection cleaner.