spluttery pop pop

[pwmotorsports]

coil replaced still no better go a nice big spark and fuel getting in ok compression is fine also............ ideas?
next step i think is cam cover off and look at valves

[trxify]

Any progress made? (in a similar boat)

[davamb]

Me also. It all started after riding in a big downpour. Bike stopped completely. Found water in carbs, cleaned them (and replaced emulsion tubes at the same time). Diaphragms were both fine. No holes or tears. Still not running perfetcly.
Checked plugs - all fine. Checked all fuel and air lines.
Last thing to try was to remove the tank, drain it and clean out all the friggin rust that had settled around the pickup gauze thingies. Then did same for fuel tap and then fuel pump. Seems ok so far, but haven't had much of a run on it. Will let you know how I go.

[Sukizilla]

Check TPS connector.

[Smithers]

Nothing wrong with iridium plugs, Ive had them on two bikes and they both ran better for sure, something I really didnt expect. I just wanted long life .... but I was told by a dealer that they hate being run on a lean fuel mixture, for example dont run your tank dry. Apparently that stuffs them. Hope that gives some comfort, I love the things.
(just thought I would mention the plugs as they are a bastard to get out and iridiums make it a task you can forget)

[davamb]

Check TPS connector.

Okey dokey Sukizilla. Might also have a squizz at the sidestand switch while I'm in an electrical frame of mind...

[trxify]

Torx bit needed for those pesky tps bolts, T25? hollow tip..
I've had the carbs off so many times it's now a five minute job (which is nice) however it's NOT the carbs on mine for sure
I will identify and pulverise the offending part one of these days (Have'nt been able to work on it for ages due to work/big family commitments blah
I will and recommend you Properly test the whole ignition system one component at a time using you're lovely but little used multimeter and those seldom seen feeler and or compression gauges at the back of the garage/shed/cupboard
I have'nt fixed mine yet so i may well be talking complete bollocks
Good Luck..

[davamb]

Still haven't found weekend time to debug some more, but yesterday the bike played up again in traffic. This time I did notice something that will help me. When it started to splutter the neutral light would dim out and the rev counter sould shoot around the scale. This was made worse if I turned the headlight off and better if I turned on the fan (previous owner put in over-ride / bypass switches for both).

So it is definitely something electrical. Only two possibilities obviously, a short or an open. Adding extra load such as the headlight and fan would point in the direction of an open circuit rather than a short (such as in the regulator output of the regulator/rectifier).

I'm thinking earth return as a starting point to investigate. I had a brief look before the light faded last night. Chunky negative wire goes from battery to engine, but where's the connection from engine to frame? Not wise to just rely on bolts to do this... will be looking further into this.

[pwmotorsports]

well been busy of late but had found that the coil mount was corroded and coming away from the frame so ive made another mount for the coil now as i think this also serves as the earth for the coil ? anyway once iva had chance to ride it ill let ou know if its any diffrent but im not holding my breath on it being just a simple earth fault

[pwmotorsports]

while i think about it can it actually be valves etc if the compression is fine ? for it to run only on one surely it needs to be carb or electric related if the compression is fine? iridium plug was fine also nice big spark etc

[trixynut]

No fresh ideas on what your issues might be, sorry mate, but I've got a complete loom, CDI, Reg/Rec etc I'm going to be selling soon if you want to change some parts. Sorry, no coils though.

[Mincehead]

Still haven't found weekend time to debug some more, but yesterday the bike played up again in traffic. This time I did notice something that will help me. When it started to splutter the neutral light would dim out and the rev counter sould shoot around the scale. This was made worse if I turned the headlight off and better if I turned on the fan (previous owner put in over-ride / bypass switches for both).

So it is definitely something electrical. Only two possibilities obviously, a short or an open. Adding extra load such as the headlight and fan would point in the direction of an open circuit rather than a short (such as in the regulator output of the regulator/rectifier).

I'm thinking earth return as a starting point to investigate. I had a brief look before the light faded last night. Chunky negative wire goes from battery to engine, but where's the connection from engine to frame? Not wise to just rely on bolts to do this... will be looking further into this.

DEFINATELY and earthing issue.

[pwmotorsports]

No fresh ideas on what your issues might be, sorry mate, but I've got a complete loom, CDI, Reg/Rec etc I'm going to be selling soon if you want to change some parts. Sorry, no coils though.

ive done coil so not that and plugs so again not that was thinking maybe reg rec next but have to take it down the rd tommorow to see if the earth solved it as stationary its hard to tell its when you go to give it some and its gutless and pulls poorly then starts to run real bad longer you run worse it gets till it wants to die......

[trxify]

When the reg/rec went on my old cbr100f the bike would stall and stutter and eventually cut out. It was pretty easy to identify with a multimeter though with only 11 volts across the battery terminals no matter how much you revved it.
The voltage should stabilise at around 13.5? at a certain amount of revs (4500?) to keep the battery charged up as well as keep the bike running.

I Think you're having fuel delivery issues like myself.. Can't find the time to work on it unfortunately

[davamb]

DEFINATELY an earthing issue.

Crimped up an extra high-current lead to go from battery negative to nearby frame point (collant reservoir mount) over the weekend. Now to see if it makes any difference!