So put the bike back together after my incident. Went for a quick spin around the block. At first I was thinking something was bent but then I realised it might be head stock bearings to tight so did check. Bike felt like it is pulling but when I did let go of bars it was going straight and bars were straight, well as much as one can spot while moving!!!!. First bump made me realise bearings are to tight as bike was weaving due to front end steering slowly from left to right not being all that stable. Did I test I was one's instructed to do. I tried turning it with my body not using bars to steer and bike was doing what I told it to but each time on the way up it felt stiff and was doing everything with a delay and progressive speed increase. So slowly up then a bit faster and faster and faster till I countered to keep it up but my countering effect was slightly delayed so it over steered and I had to counter again and again till it was impossible to do it with just the body. Quick trip to garage, lift front and yes it feels tight-ish. Loosen top yoke, a quick tap on the bearing nut and all better. Still feels all that smidge to tight when moving but will give it 100 miles as it might just need to bed in a bit. It is not weaving on bumps no more. During all that testing I noticed my new 6k miles in clutch, that was dragging since rebuilt and any attempt to fix it failed in long term, was slipping. Before any comments, it was with 4 dealers before I gave up. All that was established is it is not lifting enough even with stock slave. Took it out to discover one plate no friction material, others almost gone. Pack height 34.5mm and dragging in 1st gear!!!! Time to solve the dragging issue. I move the pressure plate, push rod and clutch pack from SS where it is working fine after 38k miles, go figure. Pack height 35.5mm. Had to remove spacer from my Oberon slave to accommodate later type longer push rod. Put it all in and what a change to clutch feel with engine on and in 1st no drag I can feel. I now actually can feel the bight point rather then operate a on/off clutch that I gotten used to. Quick spin, bike responds better to acceleration, engine speed now feels like it matches gear/road speed. Engine braking is harder. However now, only during engine braking, about 4k RPM it pops from exhaust. It was always gargling on those pipes on overrun. However now amongst gargling there is an occasional pop, not loud but muffled, base-y in sound. At any time if I open the throttle reaction is instant and gargling/popping stops. Speedo was acting up during those pops by jumping rev's to max and back but that was familiar and as suspected rpm pickup wire run close to coils, touching sparkplug and coils so was getting extra signals. Any idea why the sudden popping? Bike is running rich and my only idea is now that clutch is not slipping during engine braking there is to much fuel dumped down the pipes so it pops. It only happens on lower RPM as that is where it runs way to rich.
out of the many reasons that could cause popping on overrun in general, the most common cause is usually idle mixture screws set wrong (or galleries blocked) or balance between two bodies wrong.
Well being it did not do it before incident and did not notice doing it with old slipping clutch (that might not be related at all) would it be possible for mixture screws and balance be screwed during an off?
no it wouldn't. You still have FCR's fitted i'm guessing - are they 'a pair' or separate each with own throttle cable? also, since it's stood for a while - did fuel filter look brown inside and did you need to change it?
FCR's in, a pair as am not crazy and fuel filter is fine. Honestly it was fine on the Horsham piazza day run. It was fine after I fixed incident damage but before I changed the clutch pack. It started right after that.
procedure easier to describe on phone but to crudely try and obtain more symptoms you can :- warm up bike and make sure it's idling fairly happy then wind idle up to 1500/2000 (easy on FCR) and turn off. Remove one pluglead find another plug to insert in cap and rest on head/crankcase so it earths. Start engine without touching throttle, let it settle and note revs on tacho (don't run for long like this). Turn off and re-attach pluglead and run on two cylinders to check ok. Turn off and repeat procedure with other cylinder to compare revs.
Could it be something to do with the clutch? Could slowing down with clutch in stop the popping? And now you have sorted it like you said you have stopped pulling clutch lever in and out Does that make sense
That is genius. Would it not be better to remove the sparkplug so fuel does not collect in cylinder? I know what you mean but it is popping at certain rev range mainly and that is 4k. At 4k I would not pull the clutch in yet for another 1k - 1.5k. But might be worth investigating.
I just had a quick look on popping and going by what you had said found this WHEN DECELERATING THE ENGINE BRIEFLY LOSES VACCUME THENSE SHUTTING THE AIR CUT OFF VALVE ON MOST CYCLES IF YOUR ENGINE IS IMPROPERLY TUNED THEN YOUR INTAKE AIR PLATE WILL BE OPEN MORE ON IDLE AND LET IN MORE AIR CAUSING BACKFIRING. MOST CYCLES WIL NOT BACKFIRE IF YOU PULL IN THE CLUTCH WHICH IS THE PROPER WAY TO DECELERATE ANYWAY Thought it could be an avenue when said you pulled clutch in and out The things I do for you
Hmm Ducbird Hmm. Might play with idle adjustment on FCR's as what it is in essence is screw that keeps throttle slightly open. As my bike was dragging when stationary in 1st (not possible to put neutral because of that) I had to up the idle revs to counter increased drag on engine. After clutch change I did not touch it.
Re: plug in or out - definitely leave it in L.. it needs it in to balance running and you won't be doing it for more than 2 minutes. That's why you start it up on two cylinders inbetween tests to clear any possible fouling of plug.
