11 replies to this topic

[fimlimbimjim]

Hi
I have just bought a 1993/4 ish climber as a non runner.

Some one has been in at the disc valve which was out, but I have
set it as per the www.rotax.co.uk uk parts list instructions (I think).

The previous owner has apparently changed the piston and rings
due to low compression. The bike now has very strong compression
maybe a little more than I would expect.

I have checked over the carb and this looks to be set up just about right.
105 main jet and needle clip second from the bottom.

I have tried the old squirt wd40 in the carb mouth to get over any carb problems.
(I know this sounds a bit daft but its worked for me as an indicator for many years)
This only leads to the occasional strong back fire through the carb or exhaust.


This makes me think its an ignition problem.
I have checked the rotor and stator, the ignition pickups are aligned
at TDC give or take a smidgin.

There is a very good spark but it almost seems to come too often

My feeling is that the engines mechanicals, fuel are fine and its an electrical fault.


I don't have a wiring diagram however the CDI is marked with wire colours three of which (brown, white, red )are connected
the fourth (black) is empty but I guess this is for the kill switch and not required.

Does anyone know if CDI will fail and still spark?


I would be grateful of any advice or pearls of wisdom.

Thanks
Jim

[fimlimbimjim]

I have checked the missing black wire on the cdi.
This does seem to work as a cut off stopping the spark when connected to ground.
I have also re checked the rotary valve. this was still a bit out. I have re done it and hope it is now just about right. the bike now splutters along a bit and sort of runs.
the carb is next on the list for a recheck. Does anyone know "roughly" where to time the stator in the adjustment slot ?

thanks for any replies

[gasgas249uk]

Jim,
I used to own a 92 280 Climber and got to know the engine well.

The wiring now sounds to be correct.

The stator / timing postion will alter how the bike runs BUT it will still run .Moving the stator anticlockwise will advance the ignition. You wouldnt do much wrong in putting it in the middle position.
If it doesnt run well then , its something else.

Clean the plug - set to 25 thou
The rotary valve will usually be open when the piston is around TDC as im sure you know.
Set the needle to the middle groove.
Check you have the standard jets.

Whats the colour of the plug like?
Does it tick over ?
What sort of splutter is it / when does it do it / at what revs?

Its the standard carb , im sure. The needle and atomiser may be worn - you wont see it by eye - the needle just wont fit the atomiser it slides into.
I had a Fantic 240 that was fully rebuilt that would tick over fine , but would splutter and cough at any revs above tick over. I changed these 2 parts from dellorto and it solved the problem

Make sure your air box is getting the air it needs and not sealed around with tape , not too much oil - in fact it out to eliminate the chance that you are starving it of air.

The plug will tell you all of this

Hope this helps

Edited by gasgas249uk, 16 May 2011 - 08:38 AM.

[fimlimbimjim]

Hi thanks for the reply.
I set the stator half way and had another go today.
bike started 3rd kick and ran for about 20 seconds
before backfiring and blowing the carb off !
This is a big impovement.
I then cleaned the carb and noticed a small broken off part leaving a small 2mm hole.
it may just be an overflow. its on the right side of the carb
main body opposite the air corrector screw.

any ideas

thanks jim

[gasgas249uk]

The Dellortos have 2 L shaped over flows , one on either side of the carb body . It may not be a problem , but id check it out with pics on the net.
Its very important to know how well it was going when it was last running. Please describe
If it was running well , then theres a fault with a component. If it was running badly , then its probably not set up right

[fimlimbimjim]

Hi I bought the bike as a non runner so do not know how it went before.
I have looked on the net but cannot find a picture of a PHBH26 with a pipe where the break is.
Carb break shown below.









I've tried running the bike with the hole filled with some gloop.
It starts reasonably reliably doesn't run perfectly but I managed
to ride it around my yard. The gearbox, brakes & chassis feel quite good
I think it just needs some tweeking now.

I will have another go at the weekend.
I currently have the air screw at 1 + 1/4 turns out does anyone know the default ?

Thanks
Jim

[gasgas249uk]

That's just one of the over flows that's broken. Try retarding the stator by turning it fully clockwise. It runs so it can't be much.
Try the float valve. It may be running out of fuel.

[fimlimbimjim]

Bad news. Broke the kickstart.
The bike starts now but very regularly kicks back through the carb.(before the break)
I took the head off just to have a look
The barrel and head look great. But there appears to be 1/4mm 'ish lateral movement on the small end
didn't hear it when the engine was running.
I almost get the feeling in the CDI, maybe a capacitor is breaking down and causing the spark whenever
the voltage reaches a certain level not when the trigger coil is pulsing.

Else I may still have the inlet valve wrong. (Pretty sure it's spot on now)

Has anyone else had problems with Aprilia electrics ?

If I can't get any further in the next week I may break the bike, sure some people will need spares.

[gasgas249uk]

Gutted Jim - Those kick starts used to snap all of the time back in the day. I snapped my 1992 one.Itll be a pity if you break it for spares , but i dont know what its kine when you dont make progress on a bike , and just want shot of it.
If you do sell it , Ebay it. It'll fetcha good price there , most stuff does.

[fimlimbimjim]

I think I will hold onto it and lookout for some spares or a second bike.
It's the backfiring which confuses me unless it's electrical.
But where to find a cdi or stator to try out. Well thats all part of the fun.

[fimlimbimjim]

Hi I have sort of got around the problem by buying a running bike :-)
I will now start swapping things over to find the problem.

jim

[gasgas249uk]

fimlimbimjim, on 18 June 2011 - 01:08 PM, said:

Hi I have sort of got around the problem by buying a running bike :-)
I will now start swapping things over to find the problem.

jim

Good luck Jim, i,m glad you didnt sell it for spares