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Scooters - Big Bore => Xciting 500 => Topic started by: guile on November 21, 2013, 08:55:38 PM

Title: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 21, 2013, 08:55:38 PM
Guys, my Xciting 500 arbitrarily slows down. It sometimes doesn't want to rev up the way it used to...
It's about 40 degrees farenheit and very rainy here. Could that explain it?

Any ideas??
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: BigOrange on November 21, 2013, 10:55:50 PM
fuel injected or carb?  How old is the bike?  How old is the carb? How often do you ride it?  How many miles?  Does it need a valve adjustment?

Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: BigOrange on November 22, 2013, 04:28:20 AM
I am going to guess it has a carb.  Piston / Diaphram needs to be replaced in Carb.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 22, 2013, 07:24:58 AM
fuel injected or carb?  How old is the bike?  How old is the carb? How often do you ride it?  How many miles?  Does it need a valve adjustment?

It's a carb X form 2006. I ride it daily. It has around 20.000 miles on it; valves were recently checked, but no adjustment was needed.

Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: Vivo on November 22, 2013, 07:28:20 AM
I am going to guess it has a carb.  Piston / Diaphram needs to be replaced in Carb.

Sounds like it too...
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 22, 2013, 07:52:31 AM
Can anyone tell me which parts I will be needing?

http://www.yorkcyclesak.com/oempartfinder.htm#%2fKymco_USA%2fSAA0AE_Xciting_500%2fCarburetor%2f2K03110005%2f2K03110041 (http://www.yorkcyclesak.com/oempartfinder.htm#%2fKymco_USA%2fSAA0AE_Xciting_500%2fCarburetor%2f2K03110005%2f2K03110041)
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: Vivo on November 22, 2013, 08:55:51 AM
You really have to actually check which part is damaged...
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 22, 2013, 08:58:08 AM
Thanks. Please explain what to look for. I'm not yet experienced  with a carburetor.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on November 22, 2013, 11:25:14 AM
Lift the seat and take off the plastic carb access cover. There is the top of your carb. Remove the 3 or 4 screws that hold the cover/round bowl looking thing. There is your rubber diaphragm/slide. Look for tiny tear. Mine looked fine until I pressed very lightly around the diaphragm with a very small screw driver. By pressing on the rubber D I could see where it was torn about 2/3 mm. That's all it takes. I would take it to a dealer. It is only about a 10 minute job. U can do it your self, but sometimes you have to apply grease to the new D to make it stay seated in the recessed grove in the top of the carb to be able to put the cover/top of carb back on. It also has/is spring loaded. No big deal. But remember that it is there so you will not drop and lose spring. It's not a strong spring, but it can pop off and drop to ground. Also when u pull slide out, the needle jet will fall out when turned over. It's all very simple, but if u have never worked on a carb before, maybe it's better to let the shop do it. I think the part is under $40.00 They go bad due to the crappy gas we now have. Good luck. :-*
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on November 22, 2013, 11:37:20 AM
Sorry, did not see your link. There are 4 screws to remove. Vacume piston comp. 1402-828-2601. $46.28 In the exploded view u can clearly see the needle and such. The needle and little plastic piece just drop down inside the the top part of the new VPC. Drop those inside the new VPC apply grease to outer edge of rubber D, slip/snap down into recessed grove in top of carb, place spring in middle of cover, replace gently to seat cover on carb, replace 4 screws and your done. :-* 
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 22, 2013, 03:08:52 PM
Thanks very much Sissy.

I went to the dealer and he took the diaphragm out and he did not see any faults. He thinks it has to do with a too lean mixture that in cold weather acts up. He tuned the needle fot a richer mixture around 4000 rpm. He said a richer mixture in higher rpm's needs a different jet.
I took it for a testride and although the engine feels a bit more lively it still won't pass 6500 rpm (+/- 80 mph). Coming out of a slipstream of a big truck it picked up all of a sudden and revved to 8000 rpm; a minute later it stalls again... (to explain the high revs: the X has a Malossi Multivar variator installed; almost 18.000 miles on it now).
It's a weird problem all in all; very unpredictable behaviour.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on November 22, 2013, 06:05:53 PM
I don't know if the mallossi var has anything to do with it? But maybe the fuel pump is going out/not enough pressure? Maybe tech can measure pressure of pump?  :-*
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: BigOrange on November 25, 2013, 03:46:31 AM
Have you replaced the diaphram before?  No. It is the diapharam.  I don't care how many miles it is still a 7 year old rubber component.  They wear out.  It is your issue.  Your gas mileage was great, right? On the flat no problem any hill even a small one like rolling a boulder uphill and no power.  It is the diapharam.

Replace it and go back to the original setting on the air fuel.  These machines are finnikey when you screw with the air fuel mixture.  Too lean burn the piston crown, too rich foul the plugs.  Clean or replace the air filter as well.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on November 25, 2013, 11:13:51 PM
I agree with big o. I would also add a new fuel filter. :-*
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 26, 2013, 12:28:06 PM
Have you replaced the diaphram before?  No. It is the diapharam.  I don't care how many miles it is still a 7 year old rubber component.  They wear out.  It is your issue.  Your gas mileage was great, right? On the flat no problem any hill even a small one like rolling a boulder uphill and no power.  It is the diapharam.

Replace it and go back to the original setting on the air fuel.  These machines are finnikey when you screw with the air fuel mixture.  Too lean burn the piston crown, too rich foul the plugs.  Clean or replace the air filter as well.

Thanks for your reply. You convinced me to buy a diaphram. I will post the results as soon as I have it in ans installed.

I replaced the air- and fuelfilter recently so I don't expect problems coming from them.

The tech said he tuned the mixture a bit richer (he sais only half a millimeter). How should I put it in its original state? Up or down?

Thanks again you all for your replies!
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on November 26, 2013, 02:56:50 PM
It sounds as if he raised the needle jet by one notch? Or used a washer to lift it? Just have him put it back to stock settings.  :-*
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on November 26, 2013, 02:59:45 PM
I would have to travel quite a bit to have him do that. I think I would have to put it downwards one notch then?
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on November 27, 2013, 08:44:56 AM
He might have played with the air jet and not the needle? Who knows? That's why I said to have him set it back to stock, you don't know what he's done. :-*
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on December 12, 2013, 04:23:54 PM
Have you replaced the diaphram before?  No. It is the diapharam.  I don't care how many miles it is still a 7 year old rubber component.  They wear out.  It is your issue.  Your gas mileage was great, right? On the flat no problem any hill even a small one like rolling a boulder uphill and no power.  It is the diapharam.

Replace it and go back to the original setting on the air fuel.  These machines are finnikey when you screw with the air fuel mixture.  Too lean burn the piston crown, too rich foul the plugs.  Clean or replace the air filter as well.

BigOrange, your assessment was spot on! I installed a new diaphram and I can jump and bounce around in traffic again like never before!
Thanks very much.

Regards from the Netherlands,
Gijs
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: BigOrange on December 13, 2013, 12:54:20 AM
 :) I am happy to help.  The forum has been a great help to me.  I am lucky and have a great local dealer that is honest.

It is way more fun with a working scoot. Safe travels!
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on March 31, 2015, 07:29:02 AM
Have you replaced the diaphram before?  No. It is the diapharam.  I don't care how many miles it is still a 7 year old rubber component.  They wear out.  It is your issue.  Your gas mileage was great, right? On the flat no problem any hill even a small one like rolling a boulder uphill and no power.  It is the diapharam.

Replace it and go back to the original setting on the air fuel.  These machines are finnikey when you screw with the air fuel mixture.  Too lean burn the piston crown, too rich foul the plugs.  Clean or replace the air filter as well.

Unfortunately, I have to re-open this thread. After having replaced the diaprahm the scoot was very responsive again, but lately I'm experiencing exactly the same problems as described above  :(
Could the diaphram be worn already?
Please advice.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on April 03, 2015, 12:17:31 PM
Please guys, I need help.
I'm never sure if it will rev up to the normal maximum (7000 - 8000 rpm). Sometimes I'm stuck at 50-60 mph!
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: BettinANDlosing on April 03, 2015, 02:40:00 PM
Have you had your belt and rollers checked out?
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on April 03, 2015, 08:07:34 PM
No. Belt should be fine, second one installed about 10.000 miles ago.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: BettinANDlosing on April 03, 2015, 09:32:32 PM
No. Belt should be fine, second one installed about 10.000 miles ago.

I was more thinking about flat spots on the rollers.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: ce on April 04, 2015, 03:30:42 AM
Check all your vacuum lines and fittings for wear and cracks. It sounds like you're leaking air somewhere. You have an electric fuel pump, so check the connections as well.
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: guile on April 05, 2015, 03:48:07 PM
I opened the carburetor up and checked the diaphragm. Didn't seem anything wrong with it. I polished the  piston. Putting the diaphragm back was a real pita. The diaphragm gets bigger in time (gas?) and won't fit the groove. So I put the diaphragm in the freezer to shrink it a little and it fit after some cursing.
But what's more important is that it runs fine now. I accelerates normally and revs up to 8000 rpm  ;D
I hope this solved the problem permanently :-\
Title: Re: Xciting 500 arbitrarily slow, doesn't rev up normally
Post by: sissy mary on April 05, 2015, 04:38:04 PM
Next time put grease down inside the carb groove that the diaphragm seats into. That will hold it in long enough for you to put the carb top/lid back on. You may have gotten a bad diaphragm, or the mechanic may have torn it when installing? The rubber is pretty thin!  :-*