Bean Can repair

[(RIP) maverick]

Have anybody tried something similar before as to this link

Replacing the hall effect sensor

I have a R80TIC which was working fine one moment, sorted a few bits out for MOT. Brakes, indicators, horn, brake light switch, fork seals, tighten headstock the usual suspects but nothing to do with the ignition whatsover. It was running perfectly fine until the MOT. Parked it up and couple of days later when we started it up would only run on one cylinder

Sometimes it fires up on one cylinder some times on both. So far I have checked

Coils - swapped with another bike
ICU - swapped and checked
Plugs
Plug wires
Carburettors - checked and cleaned

Anything over 2k rpm it seems to run fine. When I close the throttle it sometimes dies or backfires quite loudly, when shutting the throttle riding under 2k rpm between cars it will also pop and backfire randomly.

My next guess is the bean can/ignition triggering unit, I will swap it out with another bikes unit and check, was just wondering if anyone tried to fix them before?

Is it basically the Hall Sensor that goes faulty in the bean can or something else? The hall sensor is just over £10 and some fiddling as per above link compared to a new or 2nd hand unit which seems quite expensive.

 

[DrFarkoff]

Are you sure you've not got a carb overfull on the sidestand?

Rush of liquid kills spark and clears after a few revs

Hall sensor tend to die or cause Inexplicable erratic running

and they are siamese coils so the fire at the same time so a fuel prob more likely

Backfiring on over run Could be drawing air in somewhere

 

[(RIP) maverick]

Are you sure you've not got a carb overfull on the sidestand?

Rush of liquid kills spark and clears after a few revs

Hall sensor tend to die or cause Inexplicable erratic running

and they are siamese coils so the fire at the same time so a fuel prob more likely

Backfiring on over run Could be drawing air in somewhere

Not sure Jaythro how do I check whether the carbs overfull? I hardly ever use the sidestand and it is always stored on the main stand overnight

When I realised it was only starting up on one cylinder I checked the offside? (sidestand side) plug for spark and there was nothing although the near side was fine.

On the motorway running around 4-4.5k rpm it does not miss or backfire it goes fine. It is only when I slow down for traffic that it will either die when I pull the clutch in or if I keep the throttle open slightly it will give a almighty bang

Is there a way to check the bean can short of swapping it around with another unit?

I would be surprised if it is drawing air somewhere as we did not fiddle with anything related to that at all before the problem.

 

[DrFarkoff]

The float level is adjustable

Carefully tweaking the tang you want the flow to just stop when the seam on the float is parallel with the base of the carb

Because it's a breaking down of the pulse usually when hot it's not really possible to test

But a known good unit will indicate if your problem lies there

Airheads can't spark on one side and not t'other cos they are a waste spark system with both plugs firing simultaneously

So my feeling is coil / coil lead / plug if you say no spark on one side

 

[Rob Farmer]

Maverick,

What year is your bike?

If it's 79/80 it will have a bean can but there will be points in there instead of an electronic pick up.

 

[Rob Farmer]

The hall sensor is just over £10

Where are you getting them from? I ordered from farnell/Newark. They appear to be cheap but there is a minimum order + postage. It worked out to around £54 for 3.

 

[(RIP) maverick]

This is a 1984 and not points/condensor model Rob. I just looked at Farnell site earlier but did not see the minum order

Will check the float level when I get home and test again before I swap the cans around. Jaythro I was also thinking it must be the coil/plug or lead but that would mean that my other bike's coils are also on their way out

 

[Rob Farmer]

It may have changed since I order the hall sensors. the minimum was higher because the sensors had to come from the States. Just looked at their site

It says :-

Placing Card Orders
Use your card to place an order via any channel:*

Phone: 08447 11 11 11 (8am - 8pm, Monday - Friday) (9am - 12pm, Saturday)

Web: www.farnell.co.uk (£20 minimum order value applies)

e-mail: [email protected]

Fax: 08447 11 11 12

*£20 minimum order value applies to all credit card orders

There is also a £15 one of chrge with each order from the states http://uk.farnell.com/honeywell-s-c/2av54/hall-effect-magnetic-sensor/dp/2093844?Ntt=Honeywell+2AV54 so 3 will cost you £46(ish) + Vat

 

[(RIP) maverick]

Rob have you had success in repairing these before?

 

[Rob Farmer]

Done a couple but not for a while. I made a mandrel as per ebbo's page http://www.ebbo.org/2av54.php I've no idea what happened to the mandrel

be a good excuse for you to fire up that lathe of yours.

 

[(RIP) maverick]

Thanks for the info Rob, will test it with another unit first to check whether that is the problem. I adjusted the float levels slightly on my way home tonight but made no difference.

What I can't understand is that it only happens when I throttle down and it goes under 2k rpm. Above that it seems to run fine and no missing or intermittent cut off's

Would a loose wire somewhere earthing or not making proper contact be able to cause something like this?

 

[Rob Farmer]

Have you checked valve clearances? You get similar symptoms if the inlet valves slightly open.

 

[toadjam]

misfire

if its the sensor wouldn't it spark on both sides or not at all .
have you swapped ht leads / plugs .

 

[Beemerboff]

My local electronics store, Jaycar electronics, has the sensors for around $AU 10-with a quantity discount.

Order a dozen and I could probably get them to you for 70 quid the lot.

 

[steveo]

mine had similar problem , turned out to be the bearing in the bean can , when under load it was ok , so i assume it took up any slack at revs ?

 

[Beemerboff]

Just checked with Jaycar , they are now $24-, the $10- was an instore special which is no longer availible, so they end up the same price as yoursor a few bucks less.

 

[(RIP) pastyman]

As you still dont seem to be getting anywhere,can I throw another suggestion into the ring... I know you have checked the carbs, but have you included the diaphragms. I had one once with a tiny split which did all sorts of silly things at different revs. Sometimes it seemed ok then at others it would cough and run dog rough........ Only a suggestion

 

[(RIP) maverick]

Have you checked valve clearances? You get similar symptoms if the inlet valves slightly open.

I had some time this morning to check the valve clearance. The left intake was completely closed up and the right front exhaust was also very tight. Have set them to spec again and the bike sounds more responsive and starts quick as before. Won't be able to take it for a test run until tomorrow though - on baby sit duty.

When I took the rocker covers off there was loads of silicon. I replaced with new gaskets & cleaned the surfaces. Now it is pissing oil on both covers, never seen gaps like this between the heads & covers with a gasket in.

I have never ever used silicon/gasket sealer on valve covers, anyone had this problem before?

 

[Kenny]

It is just a threaded bar in both the rocker covers...remove this threaded bar ( x2) and lay rocker cover on a glass pane to see if they are warped.
Obviously, if warped replace or get some valve grinding paste and start those circular movements to see if they can be ground back to a straight edge....I'm sure some members will have a spare set to sell etc. I Can't see it being the actual heads that are warped.

 

[(RIP) pastyman]

Have you got them on the correct sides... They are "handed". marked L and R.