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nudedaytona
20th September 2008, 16:43
I've got a problem with the bike - its an Aprilia RS250

It won't start. I kick the shit out of it using the kickstart, what sometimes happens is there is a loud backfire type noise from the exhaust and then stalls. Othertimes it idles poorly for a few seconds before dying.

I wonder if its the exhaust gaskets? Does anyone have any ideas?

Drew
20th September 2008, 16:49
It aint the exhaust gaskets.

There are a multitude of things that could be wrong, but I'll ignore the terminal options for now.

RGV's do something similar when the battery is dead flat, or the charging system isn't working, causing week spark. (and since the RS is just an RGV rip off, I'm sure it could be common.)

Easy test is to hook it up with jumper leads to a charged battery, and try starting it.

Hope this helps.

nudedaytona
20th September 2008, 16:56
The battery was dead, but I just replaced it with a new one. Still have the problem.

TimeOut
20th September 2008, 17:00
Was the new one fully charged? if they've been sitting for a while they can lose it

nudedaytona
20th September 2008, 17:04
Yes. Just got it from the shop today and stuck it in.

Rob Taylor
20th September 2008, 23:02
Yea but you will still have to charge the new battery.Pull the plug out and check it.If crapy replace it.Try that... Maybe coil fault too.

racefactory
21st September 2008, 07:38
top end blown? that's backfire inducing isn't it?

Squiggles
21st September 2008, 19:02
havent done something silly like gotten ya ht leads mixed up? (Front on the rear and rear on the front...)

Drew
21st September 2008, 20:14
top end blown? that's backfire inducing isn't it?


I said we weren't lookin at the terminal options yet!!! LOL

I would bet teh bike would still run on one cylinder if it had melted down, unlikely to have shit itself on both at the same time.

MotoGirl
21st September 2008, 20:22
Maybe you could ask someone on the Aprilia forum (http://www.apriliaforum.com/forums/forumdisplay.php?f=19).

This is a huge resource for everything Aprilia and has helped me with my RSVR numerous times...

nudedaytona
22nd September 2008, 10:19
My thinking now is that it could be the exhaust valves (power valves). Does anyone have any experience or comments about these?

Its NOT the battery they charged it up at the shop so it was ready for me to pick up.

nudedaytona
22nd September 2008, 10:20
havent done something silly like gotten ya ht leads mixed up? (Front on the rear and rear on the front...)

Don't know what you're talking about - ht leads?

nudedaytona
22nd September 2008, 10:21
top end blown? that's backfire inducing isn't it?


I will take one cylinder off and have a look.

CookMySock
22nd September 2008, 14:32
Don't know what you're talking about - ht leads?Spark plug leads.

DB

Drew
22nd September 2008, 14:44
My thinking now is that it could be the exhaust valves (power valves). Does anyone have any experience or comments about these?

Its NOT the battery they charged it up at the shop so it was ready for me to pick up.

Yep, dropped power valves are common, but most of the time the bike will still run, on one cylinder at low RPM and the other cylinder starts firing at higher RPM.

imdying
22nd September 2008, 14:48
Have you always had to kick the shit out of it?

Correctly tuned, a single gentle prod on the kick starter will start it. Unless it has been sitting for a month or two, then you might need two kicks, but even then should go on two.

Having to kick it over more than once isn't a good sign... worse if it's been that way for a while (or been getting steadily worse).

slimjim
22nd September 2008, 15:05
dude..also check fuel line filter...cause its sounds too like no fuel dropping in, and then when its drawning after a turn over and firing.. humm not running.. fuel line fuel filter.. then garge time,,

quallman1234
22nd September 2008, 15:55
If its turning over i doubt the Powervalves have dropped.
Espically if it runs for a couple seconds.

Check the spark on both cylinders. Sounds like a bit of a foul'd plug possibly?

Is it hard to turn over or not really your just trying to kick the shit out of it because it won't possibly start with normally kicking.
Im with drew on this one, its probabaly something simple

F5 Dave
22nd September 2008, 17:33
. . . what sometimes happens is there is a loud backfire type noise from the exhaust and then stalls. Othertimes it idles poorly for a few seconds before dying. ?

. . .So of course being a 2 stroke the first thing you did was put some new plugs in it, because that is exactly what will happen if they get fouled.:rolleyes:

nudedaytona
22nd September 2008, 17:54
. . .So of course being a 2 stroke the first thing you did was put some new plugs in it, because that is exactly what will happen if they get fouled.:rolleyes:

The spark plugs are new. They are a slightly different type from the old ones. I'll have a look at them.

Cheers,

F5 Dave
22nd September 2008, 17:58
if they are slightly wet looking then 50% chance some brakeclean or a spell under a gas torch may sort them out. or not.

As a total aside a pulsar coil that has been knocked away from the flywheel can cause same issue, but unlikely.

Drew
22nd September 2008, 17:59
The spark plugs are new. They are a slightly different type from the old ones. I'll have a look at them.

Cheers,

Being new doesn't mean much, two strokes are a fickle thing, and it takes little to upset them.

Str8 Jacket
22nd September 2008, 18:01
Being new doesn't mean much, two strokes are a fickle thing, and it takes little to upset them.

He is sooooo right! Sometimes they just go BANG! :whistle:

Drew
22nd September 2008, 18:03
He is sooooo right! Sometimes they just go BANG! :whistle:

Only when you ride them luff.

Squiggles
22nd September 2008, 18:54
Had this from Jafa's rd the other day actually, if we got it going, she'd die out quick or die before she revved over 4k, engine was warm after a while, several really good kicks and a quick trip to near the redline for a wee trip and she's all good now
Spark plugs were brand new (replaced them after it coughed out) but problem remained

centercore
22nd September 2008, 21:44
My mates rg150 did similar things when it dropped a valve. We could push start it and ride around was like it had the choke on. It wouldn't idle either.

You could check if they haven't dropped?

Drew
22nd September 2008, 21:52
You could check if they haven't dropped?

I stand by my statement that it's unlikely for both sets of power valves to clip a piston at the same time, between riding it, then trying to start it.

Plugs is the first thing to check.

nudedaytona
23rd September 2008, 09:40
I took one spark plug out this morning. It didn't look too bad - just a little bit of oily stuff on it. I cleaned it up with a rag but didn't have time before work to put it back in. I'll try with the old ones too and see how it goes.

Ixion
23rd September 2008, 11:11
Fit ne wplugs. A two smoker plug that doesn't look too bad is too bad.

racefactory
23rd September 2008, 20:55
I'll second that- it's true about the plugs. get new.

Might be worth thinkign about if your bikes compression is shot as well due to worn rings/ extreme cases- barrels. If your bike is hard to start and a lot harder to start once it's warm that's a good bet the compression is down the drain. I had a look at an NSR250 the other day ( http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Motorbikes/Sports/auction-175772824.htm ) that was so bad i could put it into gear with the engine off and the engine would turn over if i pushed the bike with my feet... I don't know how it ran but it took so many kicks to start.... sounded weak as shit too. When did you last have your top end done?