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odd misfire hiccup...

PostPosted: Thu Sep 10, 2020 1:27 pm
by handsomejackuk
Hi, I seem to have an ocasional misfire / hiccup on my baghira could this be attributed to timing gear or balance shaft ? my bike has 30,000 miles on it, and I have changed the exhaust to standard but this was always on there when i had my bsm system on it... i just dont know where to look for it it seems quite a severe misfire only thing i have not done is strip the carbs down i dont really want to do that if its something more mechanical, is there anything i can look for please advise i try and get a video up tomorrow, i have turned the mixture screw out to 5 1/2 to get the bike running as best i can and need to raise the idle up a bit seems to make it a bit better.. is this normal or something to be worried about...

Re: odd misfire hiccup...

PostPosted: Fri Sep 11, 2020 3:01 am
by breakwellmz
At that sort of mileage you need to strip and clean the carbs and fit a larger pilot jet at the same time (The standard one is too small) There is a hidden filter within the carb that will be full of rubbish as well i`m sure. viewtopic.php?f=3&t=10435&hilit=+hidden+filter

Re: odd misfire hiccup...

PostPosted: Fri Sep 11, 2020 3:37 am
by Puffs
Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

Re: odd misfire hiccup...

PostPosted: Fri Sep 11, 2020 4:58 pm
by handsomejackuk
bit of an update,

I sealed the standard exhaust up a bit better today had to bend the tangs on the exhaust in a bit to get it fit tighter, i tried all manner of clamps i had some mikalor clamps but they were either to big or too small in the end i found some norma banded clamps and they seem a bit tighter although not the best qulaity...and used a bit of exhaust sealant on the pipes

I removed the spark plug and was very black and sooty.. so changed that for a spare, also as i had the seat off i took the side cover off and disconnected and reseated the cdi unit its never been off the bike.. the spade connections were a bit crusty and corroded so give them a good douse of servisol contact cleaner and cleaned them up, also set the air screw back to 2 1/2 turns out it seems to be running a lot better...i suspect i had the air screw too far out and was running it a bit too rich...

i going to do a longer run tomorrow and see how it goes..

thanks for the advice on timing chain i will certainly thin about stripping the carbs in the next few weeks i see how it runs for the moment, it did seem to be behaving much like ti used to be with needing a bit of choke to start then running better on ce worn i wonder by removing the air screw last week whether it dislodged some crud from the passages, i did think of blowing compressed air up the air screw hole once the screw was out, and draining the carb first... i dont really want to strip the carbs as we only have a few weeks of good weather here in uk

Re: odd misfire hiccup...

PostPosted: Sun Oct 11, 2020 4:45 pm
by handsomejackuk
Puffs wrote:Assuming there are no carburation or ignition issues, at 30k miles the cam chain might have stretched/worn. Maybe you can get an indication from the chain tensioner. Chain wear results in retardation of the timing; on another bike I found it surprising how much it improved from just replacing the chain. And yes, that too had an occasional misfire.

The other thing to look for is compression. Don't know what they prescribe, but it should probably be in the 10-12 bar range.

Oil consumption? Carbon can also hurt you.

Good luck!



whats test for worn timing chain.. how would i identify if its stretched. ?

Re: odd misfire hiccup...

PostPosted: Mon Oct 12, 2020 5:30 am
by Puffs
Following a biased and flawed moderator choice (someone posting aggressive personal attacks is rewarded, while my technical posts are removed - behind my back & without any justification!), I have withdrawn from this forum.

Re: odd misfire hiccup...

PostPosted: Fri Oct 16, 2020 12:54 pm
by ralf
My limited carb whispering skills suggest that a mixture screw over 5 turns out means you need a bigger pilot jet. My Skorpion (same engine?) was absolutely transformed by fitting a 54 pilot instead of the specified 48. Easier and cheaper than timing chains etc. Give it a try, no guarantees.

Re: odd misfire hiccup...

PostPosted: Fri Oct 16, 2020 12:55 pm
by ralf
My limited carb whispering skills suggest that a mixture screw over 5 turns out means you need a bigger pilot jet. My Skorpion (same engine?) was absolutely transformed by fitting a 54 pilot instead of the specified 48. Easier and cheaper than timing chains etc. Give it a try, no guarantees.