GPR Camp: Replica Racers

I have a 99 RS 50, ok so for last 3 months it sat at parents house while I traveled, I had them start it once a week so the gas wouldnt gum up in the carb. Ok so 3 days ago I finally drive 5 hrs to get my bike and it starts right up and I ride it down the street wot to get rid of the carbon build up from just starting and idling for last 3 months. Bike ran great blew all the smoke out and then put in the van and drove it 5 hrs back home. Unload the bike and it wont fire? I pulled the carb which is brand new 17mm and pull all jets and blew them out with carb cleaner and all wholes in the carb, so carb is clean. I think pull spark plug and i have spark. So I have spark and clean carb why and the hell wont it fire ??? Ive pushed start it so many times feels like Im going to have a heart attach as many times Ive pushed it.


Ok Go who has the answer??

Sounds like it's not getting gas.

If the gas is old (which it may be), I would also replace it. Drain the float bowl to confirm you have fuel there.

Next time it's going to sit, just add a fuel stabilizer and drain the floatbowl. Don't start it and run it for a short time. Use ethanol-free gas if it's available. It lasts longer and is less likely to be bad and go bad that gas with ethanol. There are also treatments for fuel with ethanol if it's the only thing you can get.

jkv357, thanks for the post. So when finally went to my parents home it started right up I drove it down the street wot to blow out all the crap, it ran great down the street. So then I load it into the minivan drive 5 hrs and unload it and now it wont run?? I pulled the carb, pulled each jet on my Dellorto 17mm carb that was bought in Dec. It looked extra clean since its new and I used carb cleaner to blow out each jet and every hole on the carb. I then check the spark plug thinking maybe I fouled the plug, I put another one in and same no go. I did notice spark was week or no spark so I pulled the wire off and cut both ends for fresh wire to screw both onto. Now I have nice big spark and It still wont run?? My battery is dying now from trying to start it so Ive pushed started it like 30 times. Ive got a couple pops like it wanted to start then bog down, and couple back fires. But at the end NADA no go. It has started 2 times with electric start but I was on my way out both times so I couldn't jump on the bike and see if I could keep it going for longer then couple seconds. Why it started those two times I have no clue since it wont do it again??


Spark, Fuel, Air? thats all I need??

It could be possible that something in the carb is not assembled correctly. Do you get a good amount of fuel out of the float bowl drain? Could the petcock or filter/screen be plugged?

Is the throttle opening and closing properly? Is the Idle Mixture adjustment set to a standard setting? Does opening the throttle slightly while cranking change anything?

Make sure the battery is full-up.

I would still replace the gas before doing much else, just so you know it's good.

Temperature or elevation significantly different from where it last ran?

well I went back down to work on the bike, took the carb off and did a complete through cleaning again, and check fuel coming out of the tank and fuel line. Nothing happened, so I pulled the plug to check spark and to my dismay no spark. Yesterday there was spark so maybe yesterday it was intermittent spark. I had the stator replaced about 6 months ago so CDI is whats left, I have to find a CDI unit now.

you have one ? lol

Interesting - glad you checked for spark again.

Not me - but someone has one...

well if I got fuel and I got a clean carb then next recheck was the spark, yesterday I had and today i dont. I even cut both end of the cable for fresh connection and nada so its come down to a CDI unit is in need.


Thanks for replying to post.

I found a CDI unit from a fellow Aprilia Forum friend he had a Top Performance Yellow CDI.

Based on the history of this bike, and that it currently has a glommed on scooter ignition from an unknown origin, it would be easy to suspect that you are having ignition problems. As I've said in the past I would just go through and replace the entire ignition system on that bike.

it came down to cdi unit, I got a Top Performance Yellow CDI and it fired right up. Im now having issue with the key not being able to turn off the bike, the kill switch works but key wont turn it off, it did before but not now ??