Two stroke help needed

Message

paddyz1 · #16 Post by **paddyz1** » Fri Feb 06, 2009 2:29 pm

shootmyscoot wrote:have you checked the float level??
take carb off, remove the bottom, get some 1 to blow down the fuel inlet and close the float, it should close level any more and that may be the cause off the flooding

sms

I am going to strip it down and give it a good clean with some carb and choke cleaner just to be sure it is clean.

Fausto · #17 Post by **Fausto** » Fri Feb 06, 2009 4:31 pm

Seeing as this seems to have happened after pouring yukky salvaged tank dredges into that lovely shiny bike it's got to be the dirty fuel.

It gets everywhere and takes a lot of cleaning out. You may have cleaned the carb but if you didn't flush the tank then the muck will reappear. It can also bugger up vacuum taps.

I would flush the tank out...... a lot !

Samray · #18 Post by **Samray** » Fri Feb 06, 2009 4:51 pm

My thoughts too Fausto for what it's worth.

paddyz1 · #19 Post by **paddyz1** » Fri Feb 06, 2009 6:04 pm

Fausto wrote:Seeing as this seems to have happened after pouring yukky salvaged tank dredges into that lovely shiny bike it's got to be the dirty fuel.

It gets everywhere and takes a lot of cleaning out. You may have cleaned the carb but if you didn't flush the tank then the muck will reappear. It can also bugger up vacuum taps.

I would flush the tank out...... a lot !

Agreed. I think it has higlighted a minor problem and brought it forward. Either the fuel tap or the float valve was faulty (i am guessing the fuel tap) and the shite fuel has gunked up the other.

BikerGran · #20 Post by **BikerGran** » Fri Feb 06, 2009 8:11 pm

If you need parts for carb or fuel tap I've found NRP Carbs very helpful. They don't actually list Aprilia parts but they show Aprilia in their list of makes, they're always wortj a phone call, very knowledgeable.

paddyz1 · #21 Post by **paddyz1** » Fri Feb 06, 2009 8:38 pm

BikerGran wrote:If you need parts for carb or fuel tap I've found NRP Carbs very helpful. They don't actually list Aprilia parts but they show Aprilia in their list of makes, they're always wortj a phone call, very knowledgeable.

Thanks BG

bookmarked

Falco9 · #22 Post by **Falco9** » Fri Feb 06, 2009 9:05 pm

paddyz1 wrote:
Fausto wrote:Seeing as this seems to have happened after pouring yukky salvaged tank dredges into that lovely shiny bike it's got to be the dirty fuel.

It gets everywhere and takes a lot of cleaning out. You may have cleaned the carb but if you didn't flush the tank then the muck will reappear. It can also bugger up vacuum taps.

I would flush the tank out...... a lot !
Agreed. I think it has higlighted a minor problem and brought it forward. Either the fuel tap or the float valve was faulty (i am guessing the fuel tap) and the shite fuel has gunked up the other.

But it doesn't explain the "Bang" though................this is whats puzzling me. What was that "actual" noise? (I know we'll never really know, but it would make it sooooooooooooooooooooo much easier to try and help you diagnose the problem)

F9

paddyz1 · #23 Post by **paddyz1** » Sat Feb 07, 2009 1:09 am

Falco9 wrote:
paddyz1 wrote:
Fausto wrote:Seeing as this seems to have happened after pouring yukky salvaged tank dredges into that lovely shiny bike it's got to be the dirty fuel.

It gets everywhere and takes a lot of cleaning out. You may have cleaned the carb but if you didn't flush the tank then the muck will reappear. It can also bugger up vacuum taps.

I would flush the tank out...... a lot !
Agreed. I think it has higlighted a minor problem and brought it forward. Either the fuel tap or the float valve was faulty (i am guessing the fuel tap) and the shite fuel has gunked up the other.
But it doesn't explain the "Bang" though................this is whats puzzling me. What was that "actual" noise? (I know we'll never really know, but it would make it sooooooooooooooooooooo much easier to try and help you diagnose the problem)

F9

This happened after it had been stood all day while the daughter was at work. She came to the bike and it spluttered and farted, then the bang. I think it had a clean plug when she parked it up and maybe it fired up but soon became flooded. Maybe enougth fuel/air to give it that one last bit of ignition before it completly fouled the plug.
I am only guessing here and have not touched the bike since Thursday.
What I do know is that it made a backfire each time I cleaned and heated the plug up before it fouled up again. I could be totaly wrong though

#24 Post by **Kwackerz** » Sat Feb 07, 2009 8:58 am

Hmm That sounds like timing or else the float sticking

Aladinsaneuk · #25 Post by **Aladinsaneuk** » Sat Feb 07, 2009 9:23 am

am also guessing timing

one of my KH's did the same - no matter how often i set the timing - then i realised that the actual stator plate was loose....

Falco9 · #26 Post by **Falco9** » Sat Feb 07, 2009 10:08 am

Now I understand. In that case I reckon the bike was completely flooded. Dependant upon the piston position a lot of fuel could have got into the crankcase which may have ingnited when she tried to start the bike. so I reckon you're on the money there

Still doesn't explain why the bike won't start now though. Have you tried another plug? if that doesn't work, I'd re-check the timing.

At the end of the day the 2 stroke is a fairly simple engine, so a simple process of elimination should get you there. Start with the easy stuff first, plug, leads, kill switch etc.... and go from there. It has always worked for me in the past.

I'm in the same process myself at the mo, with my old Yamaha 100, runs beautifully at low revs, starts 1st or 2nd kick every time, but no matter what I do, it won't rev!!! driving me mad, new plug, new points new condensor, spotless carb, checked float height you name it. Anyway that's my problem it doesn't help you I'm afraid

Best of luck getting it sorted, it look s a beautiful bike

F9

D-Rider · #27 Post by **D-Rider** » Sat Feb 07, 2009 10:20 am

She'd not be the first girl to fail to explain in detail to her dad the bang she'd had on the way home ......

Anyway, back on track, sounds as though this one's well on the way to being sorted.
Reminds me a bit of the problems my Joe used to have with his scooter when we first got it. Forever fouling plugs - they'd come out soaking. dry them and clean them and it would run for a while.
Eventually the problem just gradually improved - so not sure if these gummed up float valves could have eventually cleaned themselves or something.
I did have to replace piston and rings after he blew it up - ran much better after that.
Still very flat up the top end when speed has built up and it surges a bit there ... keep meaning to investigate - but that'll be an unrelated problem.

paddyz1 · #28 Post by **paddyz1** » Sat Feb 07, 2009 4:13 pm

Falco9 wrote:
I'm in the same process myself at the mo, with my old Yamaha 100, runs beautifully at low revs, starts 1st or 2nd kick every time, but no matter what I do, it won't rev!!! driving me mad, new plug, new points new condensor, spotless carb, checked float height you name it. Anyway that's my problem it doesn't help you I'm afraid

F9

You have probably cleaned this already....Have you removed the emulsifier tube? I always take it out and use the carb & choke cleaner to make sure all the air holes are free. I always make sure every hole gets a good dose of C&C cleaner and that I can see that it 'traveled' through the carb and come out the other end (if that makes sense

)

paddyz1 · #29 Post by **paddyz1** » Mon Feb 09, 2009 7:40 pm

UPDATE....

There was still fuel in the crank today (mon 9th) so i thought fuck it and got out the old faithful blowtouch. Lit it up and aimed the flame into the crankcase via the reed block (reed block removed). Spun the bike over and cleared out the remining fuel which was fun. I could see small bursts of flame as the fuel burnt. It was nothing much, just enougth to light up the inside of the crankcase.
Anyway, after reverting back to my butcherous days i came back to reality and set about giving the carb a good clean. Got that done so replaced the reed block,carb etc and filled the carb with fuel.

'Puut puut fart' then nothing, it just turned over without starting. Bollocks i thought. Took out the plug which was soaking again. After what some of you had said i tried another plug. This was the wrong plug (shorter reach) but it was all I had so i tried that. Started up first turn. Umm, lets try the original plug, 'Puut puut fart' and a wet plug again. So I tried the old plug and it started first time.

So this could have been a number of things wrong but one definate problem was the plug. As for the flooding of the crankcase I can only say what has been said and suggested.

So thanks for the help everyone, i'll see you in the bar, drinks are on me.

Oh, and an even though i like the RXS100, I will not be buying another one, EVER

#30 Post by **Kwackerz** » Mon Feb 09, 2009 7:56 pm

Falco9 wrote: I'm in the same process myself at the mo, with my old Yamaha 100, runs beautifully at low revs, starts 1st or 2nd kick every time, but no matter what I do, it won't rev!!! driving me mad, new plug, new points new condensor, spotless carb, checked float height you name it. Anyway that's my problem it doesn't help you I'm afraid
F9

had that when I put a replacement carb on the Vespa. Easily fixed when I found the problem. Sounds exactly the same as your problem

http://www.vespamaintenance.com/fuel/carbtune/

The pic shows the position of the two screws (writing below it explains the function they perform) that I had to piss about with on the vespa, if you can cross reference that to your RXS carb somehow, you may be in business? Main problem was the mixture screw was set in too far, but i had to adjust the idle as i opened up the mix.

Snipped from yamahaclub.com that might be of use?

For the record here are the seetings you need - but also remember that as it's a 2 stroke good crankase/carb seals are critical to getting the bike to idle well.

Air screw turns out 2 & a quarter
Float height 21mm +/- 1mm
Idle speed 1400rpm +/- 50rpm
Clip position 2

Start the bike and get it up to temperature then set the air screw as above and adjust the idle screw to obtain a reliable tickover. If this doesn't work I would dismantle the carb and make sure the idle circuit airways are clear by blowing compressed air through them, and making sure the idle jet is not obstructed. If this makes no difference then you need to look at the oil seals on the bike you can test this by spraying WD40 on the seals and seeing if that makes a difference to the running.