|
Author |
Message |
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
Posted: 02:51 - 09 Dec 2019 Post subject: Bike cuts out holding clutch in and down shifting |
|
|
Here's a video off the issue. Any ideas?
Its a Zontes Mantis 2018.
https://youtu.be/LAP6No_knl4
Can't upload as attachment? |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Teflon-Mike |
This post is not being displayed .
|
Teflon-Mike tl;dr
Joined: 01 Jun 2010 Karma :
|
Posted: 04:29 - 09 Dec 2019 Post subject: |
|
|
An engine needs 3 things to run; air/fuel, sparks and compression.
This bike runs, sol what ever is missing is only missing when the engine is a) presumably warm b) the throttle closed on the down-shift, and momentum driving the back wheel isn't being transmitted to the crank through the gearbox.
It would look like a fairly recent chinky bike, which suggests fuel injection, and a very lean 'map' in the squirter box, that likely nills fuel when the throttle closed 'cos of emissions, loik.
Silly Questions first; When was it last serviced... and was it done properly.. and dont assume that if it was done by a dealer it must have been....
3-things remember; spark, charge and compression.
If the thing hasn't been serviced or serviced properly recently, then you can loose compression from tight tappet clerances; you can loose sparks cos of a idirty plug, and on an EFI engine, charhe from all manner of things, starting the list with a dirty air-filter;' next usual suspect would be the THrottle position sensor, often a carbon track poentiometer some-where, that gets dirty and makes the squinter box believe the throttle's more shut than it is; then you have the exhaust sensor on a 'closed-loop' EFI system, which in crap weather of late could be giving errant signal cos of water vapour in the exhaust, or it's contact could have got dirty or been dislodged.. or or or.....
OR, and is usually the case, its a cumulative effect of a clusterchuck of 'little' problems... B-U-T you got the list; spark; compression; charge; you have the bike in-front of you, we don't, you poke and prod, and top tip, get a service manual, and start with the instructions for a normal 'service'.. change the plug; clean the air-filter, tickle the tappets, lube the throttle cable(s), change the engine oil, etc etc etc, and base line what it's NOT then go look for what it might be, after... good odds that basic service and new plug will 'fix' it though... but remember the clucterchuck effect... it may seem to go away, b-u-t, unless everything properly done, it'll be back.... ____________________ My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?' |
|
Back to top |
|
You must be logged in to rate posts |
|
|
doggone |
This post is not being displayed .
|
doggone World Chat Champion
Joined: 20 May 2004 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
MCN |
This post is not being displayed .
|
MCN Super Spammer
Joined: 22 Jul 2015 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
Posted: 15:06 - 09 Dec 2019 Post subject: |
|
|
Teflon-Mike wrote: | An engine needs 3 things to run; air/fuel, sparks and compression.
This bike runs, sol what ever is missing is only missing when the engine is a) presumably warm b) the throttle closed on the down-shift, and momentum driving the back wheel isn't being transmitted to the crank through the gearbox.
It would look like a fairly recent chinky bike, which suggests fuel injection, and a very lean 'map' in the squirter box, that likely nills fuel when the throttle closed 'cos of emissions, loik.
Silly Questions first; When was it last serviced... and was it done properly.. and dont assume that if it was done by a dealer it must have been....
3-things remember; spark, charge and compression.
If the thing hasn't been serviced or serviced properly recently, then you can loose compression from tight tappet clerances; you can loose sparks cos of a idirty plug, and on an EFI engine, charhe from all manner of things, starting the list with a dirty air-filter;' next usual suspect would be the THrottle position sensor, often a carbon track poentiometer some-where, that gets dirty and makes the squinter box believe the throttle's more shut than it is; then you have the exhaust sensor on a 'closed-loop' EFI system, which in crap weather of late could be giving errant signal cos of water vapour in the exhaust, or it's contact could have got dirty or been dislodged.. or or or.....
OR, and is usually the case, its a cumulative effect of a clusterchuck of 'little' problems... B-U-T you got the list; spark; compression; charge; you have the bike in-front of you, we don't, you poke and prod, and top tip, get a service manual, and start with the instructions for a normal 'service'.. change the plug; clean the air-filter, tickle the tappets, lube the throttle cable(s), change the engine oil, etc etc etc, and base line what it's NOT then go look for what it might be, after... good odds that basic service and new plug will 'fix' it though... but remember the clucterchuck effect... it may seem to go away, b-u-t, unless everything properly done, it'll be back.... |
it had a dealer service 600 miles ago,i also cleaned the air filter last week, planning on getting a better spark plug this week,
i am getting a new fuel pump fitted this week, but the revs stay above idle for a few secs if i rev the engine slightly. too
this video was coming to a complete stop, it aint the side stand (too the last comment) |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Robby |
This post is not being displayed .
|
Robby Dirty Old Man
Joined: 16 May 2002 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
iooi |
This post is not being displayed .
|
iooi Super Spammer
Joined: 14 Jan 2007 Karma :
|
Posted: 15:58 - 09 Dec 2019 Post subject: |
|
|
What happened to blipping throttle on down shifts? ____________________ Just because my bike was A DIVVY, does not mean i am...... |
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
jaffa90 |
This post is not being displayed .
|
jaffa90 World Chat Champion
Joined: 06 Apr 2016 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
Teflon-Mike |
This post is not being displayed .
|
Teflon-Mike tl;dr
Joined: 01 Jun 2010 Karma :
|
Posted: 02:14 - 10 Dec 2019 Post subject: |
|
|
Lets think about this for a second; there's a dealer; who'c supposed to have 'fixed' the thing, presumably has passed motorbike tests, and ridden bikes for a few years... and there's you.. probably a CBT no-nuffink hat has managed to wobble around a few cones in a car-park, and admits to not having a lot of experience? Hmmmm.... whose opinion do you think should hold more weight?
Oh-Kay.... now when you have finished spluttering.... DO you per-chance, ride on the gears, short-shifting, getting into as highj a cog as you can as early as you can, cos it sounds and feels like you are torturing the poor little engine else? Do you THEN, slowing down, 'rush' the down-shifts, essentially clutch 'in' coasting, as you try and crsh down all them gears you have short shifted 'up'? And THAT is when, throttle closed, EFI brain believing it dont 'need' chuck fuel in to keep the engine running, it 'dont' and the motor dies?
Right now, whilst I tend not to have too much faith in dealers or thier mechanics, I am S-O-R-T of leaning towards their point of view.. its probable that the bike isn't quite right, B-U-T, remember cluster-chuck effect, more than small odds that the 'problem' is largely 'user error'... A~N~F if you let the little fecker rev a bit, used the lower gears, and came down them a bit more sensibly, and gave it time for 'engine braking' to work, and motor the engine over when the throttle closed, it WOULDN'T die so easily, and the 'problem' would significantly go-away...
Give it a go.. try revving the little fecker asnd NOT spending so long, SO often in the taller gears, OR trying to do all your slowing clutch in, on the braakes... use that engine braking. ____________________ My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?' |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Kentol750 |
This post is not being displayed .
|
Kentol750 World Chat Champion
Joined: 24 May 2016 Karma :
|
Posted: 03:13 - 10 Dec 2019 Post subject: |
|
|
____________________ Some bikes. |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Nobby the Bastard |
This post is not being displayed .
|
Nobby the Bastard Harley Gaydar
Joined: 16 Aug 2013 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
flea-rider |
This post is not being displayed .
|
flea-rider L Plate Warrior
Joined: 15 Oct 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
Posted: 22:19 - 10 Dec 2019 Post subject: |
|
|
Teflon-Mike wrote: | Lets think about this for a second; there's a dealer; who'c supposed to have 'fixed' the thing, presumably has passed motorbike tests, and ridden bikes for a few years... and there's you.. probably a CBT no-nuffink hat has managed to wobble around a few cones in a car-park, and admits to not having a lot of experience? Hmmmm.... whose opinion do you think should hold more weight?
Oh-Kay.... now when you have finished spluttering.... DO you per-chance, ride on the gears, short-shifting, getting into as highj a cog as you can as early as you can, cos it sounds and feels like you are torturing the poor little engine else? Do you THEN, slowing down, 'rush' the down-shifts, essentially clutch 'in' coasting, as you try and crsh down all them gears you have short shifted 'up'? And THAT is when, throttle closed, EFI brain believing it dont 'need' chuck fuel in to keep the engine running, it 'dont' and the motor dies?
Right now, whilst I tend not to have too much faith in dealers or thier mechanics, I am S-O-R-T of leaning towards their point of view.. its probable that the bike isn't quite right, B-U-T, remember cluster-chuck effect, more than small odds that the 'problem' is largely 'user error'... A~N~F if you let the little fecker rev a bit, used the lower gears, and came down them a bit more sensibly, and gave it time for 'engine braking' to work, and motor the engine over when the throttle closed, it WOULDN'T die so easily, and the 'problem' would significantly go-away...
Give it a go.. try revving the little fecker asnd NOT spending so long, SO often in the taller gears, OR trying to do all your slowing clutch in, on the braakes... use that engine braking. |
Buddy. I had a mechanic friend and someone with 30 years riding experience to try it.
My fuel pump has arrived and I brought a NGK spark plug arriving tomorrow, |
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
Posted: 22:34 - 10 Dec 2019 Post subject: |
|
|
Teflon-Mike wrote: | Lets think about this for a second; there's a dealer; who'c supposed to have 'fixed' the thing, presumably has passed motorbike tests, and ridden bikes for a few years... and there's you.. probably a CBT no-nuffink hat has managed to wobble around a few cones in a car-park, and admits to not having a lot of experience? Hmmmm.... whose opinion do you think should hold more weight?
Oh-Kay.... now when you have finished spluttering.... DO you per-chance, ride on the gears, short-shifting, getting into as highj a cog as you can as early as you can, cos it sounds and feels like you are torturing the poor little engine else? Do you THEN, slowing down, 'rush' the down-shifts, essentially clutch 'in' coasting, as you try and crsh down all them gears you have short shifted 'up'? And THAT is when, throttle closed, EFI brain believing it dont 'need' chuck fuel in to keep the engine running, it 'dont' and the motor dies?
Right now, whilst I tend not to have too much faith in dealers or thier mechanics, I am S-O-R-T of leaning towards their point of view.. its probable that the bike isn't quite right, B-U-T, remember cluster-chuck effect, more than small odds that the 'problem' is largely 'user error'... A~N~F if you let the little fecker rev a bit, used the lower gears, and came down them a bit more sensibly, and gave it time for 'engine braking' to work, and motor the engine over when the throttle closed, it WOULDN'T die so easily, and the 'problem' would significantly go-away...
Give it a go.. try revving the little fecker asnd NOT spending so long, SO often in the taller gears, OR trying to do all your slowing clutch in, on the braakes... use that engine braking. |
I also tried bliping the throttle and sometime it still does it.
The mechanic "fixed" the rear break by placing the calibre yet its still spongy as fuck and shouldn't need to be pressed fully down to the end point don't feel much resistance or pressure. Also the bike rpms shoot up if u rev it and stay up for a few seconds around 3k rpm but happened to max 9k rpm at one point for 5 seconds
And no way shape or form did i say I'm some master riding I've only done 200 miles since owning it for a month involving no car parks neither, all roads. |
|
Back to top |
|
You must be logged in to rate posts |
|
|
Robby |
This post is not being displayed .
|
Robby Dirty Old Man
Joined: 16 May 2002 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
Easy-X |
This post is not being displayed .
|
Easy-X Super Spammer
Joined: 08 Mar 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
DisAdam |
This post is not being displayed .
|
DisAdam L Plate Warrior
Joined: 09 Dec 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
Easy-X |
This post is not being displayed .
|
Easy-X Super Spammer
Joined: 08 Mar 2019 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
Nobby the Bastard |
This post is not being displayed .
|
Nobby the Bastard Harley Gaydar
Joined: 16 Aug 2013 Karma :
|
|
Back to top |
|
You must be logged in to rate posts |
|
|
Old Thread Alert!
The last post was made 4 years, 128 days ago. Instead of replying here, would creating a new thread be more useful? |
|
|
|