Airhead Problem, Any ideas???

[GSSTEVE]

Airhead boffs out there, just looking for ideas on a not well R80 g/s 84 model.

Was out for a bit of a bimble around the Dales and had covered about 25 miles, all good, stopped for an hour and then carried on another 25 mile and stopped at a friends house and had a brew. Went to leave problem starts, starts, idles, bring on the gas 1900-2000rpm and bike dies.
You cannot even force the revs, just splutters, sometimes spits!! No go.

The g/s has been faultless since its refurb, have covered a good shakedown 500 miles and was all running sweetly..

Symptom, will start and idol on choke, soon as you bring on the throttle to about 1900/ 2000rpm the bike cuts out instantly. Start again bring on the revs and dies again and so on.

Have checked thoroughly the carbs, jets, diaphragms, linkages, float heights etc.
Full check of New coil all readings on secondary and primary windings as per the book, all resistances good, i.e. spot on readings.

The bike has a Full electronic ignition system inc the bean can with an electronic advance, again all New as is the full wiring loom. Replaced the Electronic control box with another New one and still same this controls the advance.
New spark plugs, leads, Coil, Single with 2 outlets New, New Electronic regulator.
New battery holding 12.8 volts.

I am open to all ideas and your Airhead knowledge base, I know it's just a process of elimination but someone may have had similar symptoms on there machine..
It's certainly foxing me for now??
Thanks in advance
Steve.

 

[Ogmios]

Fuel starvation?
Particularly, dirty filter(s) and the vent in the filler cap.

Good Luck.

 

[solidstate100]

I would swear its out of fuel, or fuel starvation at least....you HAVE checked the fuel level, no?

 

[GSSTEVE]

Thanks so far, cleaned carbs thoroughly when put back on bike after rebuild and rechecked again now, all float height/ level all good.
Have ran with no petrol cap off and feeding carbs straight via fuel lines, still the same.
As I say the bike has been running spot on, I just stopped for 1/2 hr and the problem arose. I always try and wind back odd noises or uneven power delivery and it was running a beaut!
As soon as it reaches 2000rpm it just cuts out like the ignition has been turned off instantly.

Keep the brain waves coming, thank you.
Steve

 

[JJH]

Why not run it to 2000 with a plug out and Earth the plug and watch for the spark to die at 2000 rpm. JJH

 

[Damien]

Have you pulled the petcock and checked the filter in the tank?

 

[DrFarkoff]

change the bean can for std one

Sounds like some one has used one of those crap CYHME56 sensors I went through 3 of a batch of 6 before I figured it was the sensor @ approx 1800 revs they just cut out but would restart and run as long as you didnt exceed 1800 rpm

You could try a 1 K ohm bridge between 12v and the sensor wire (what the tech suggested I tried with the batch I had)

The Clue

Symptom, will start and idol on choke, soon as you bring on the throttle to about 1900/ 2000rpm the bike cuts out instantly. Start again bring on the revs and dies again and so on..

 

[GSSTEVE]

Thanks Dr F, I am going to put original bean can etc back on when I'm back at home at the weekend, the electronic can is looking suspect. I have heard of them failing before even when new out of the box.
Thanks to all for the input, I will keep you posted and hopefully get to the bottom of it...I'm wasting riding time. I will probably put the standard parts back on as they always had-worked for 20 odd years. My bean can was converted to points and condensor and i just wanted ease of electronic. There's me thinking modern electronics were the future!!
Steve

 

[GSSTEVE]

Problem solved..

All sorted, back out on the road..turns out it was the bean can which has been replaced by the supplier no problem.
I hope this was a one off and only time will tell.
Thanks for all the input here, much appreciated, and the suppliers who have been 100%.
Steve

 

[Sunny Jim]

Looks very nice Steve - Scar House Res too

(One of my favourite rides and getting built into the ride-out I'll take at the Dent weekend)

 

[solidstate100]

Nice!

Just out of interest, are those tyres Distanzia's? any good?

 

[tuftywhite]

Nice!

Just out of interest, are those tyres Distanzia's? any good?

As you mention tyres, I've got my Metzelers fitted and I'm really pleased with them. Especially after the TKC's. Very smooth. I had Distanzias before the TKC's. They were okay, but never bonded like I did with the Gripsters. Happy with the Metzelers so may stick with them.

GSSteve, great bike. Glad you got the problem sorted.

 

[GSSTEVE]

Yes the tyres are Distanzia's as they stopped producing the Gripsters. It's had Gripsters for the last 20 odd years and they were a great all rounder, and they were a good price..So far the Distanzia's feel great even in the wet, not quite off road stiley but ok for gravel trails if required and good enough to get the pegs sparking on the road
Thanks for all comments and help, I may get across to the Dent Do in late May as its just up road , may meet a few of you there to have a beer or two!
Steve

 

[solidstate100]

Yes the tyres are Distanzia's as they stopped producing the Gripsters. It's had Gripsters for the last 20 odd years and they were a great all rounder, and they were a good price..So far the Distanzia's feel great even in the wet, not quite off road stiley but ok for gravel trails if required and good enough to get the pegs sparking on the road
Thanks for all comments and help, I may get across to the Dent Do in late May as its just up road , may meet a few of you there to have a beer or two!
Steve

Cool, thanks for the feedback chaps, may well give the Distanzias a go after I wear out the Metzeler enduro 1 and 2's (which I am pretty happy with) I have on at the mo, pays to try em all out dunnit!

 

[thestockcar]

looks v.nice and good to see you got sussed.....