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Loss of tickover and poor starting,help please.

Posted: Mon Aug 31, 2009 12:57 pm
by ove
Tickover was fine before but now can`t get it to tickover.
On way home from work this morning (35miles) coming up to final roundabout,scooter seemed to bog down. Was boggy pulling away. kept revs high so not to cut out, Once home stopped and it cut out. Couldn`t start it,stripped carb and gave it a quick clean,it then started but no tickover. Tried to start again,no go :( If i take airfilter off it will start but no tickover.
I can`t see any visible leaks,carb manifold,exhaust or head? will double check later.
Scooter is Li150 mugello 186,42mm clubman,28pbhb carb.
As i said it has been running fine.
Help please as Mersea is calling.

Re: Loss of tickover and poor starting,help please.

Posted: Mon Aug 31, 2009 1:25 pm
by drunkmunkey6969
Oil seals blown?

Check to see if any oil is dripping from mag housing or behined stator plate.

Re: Loss of tickover and poor starting,help please.

Posted: Mon Aug 31, 2009 6:08 pm
by ove
Cheers Drunkmunkey6969
Mag seems to be oil free,will pull flywheel off later(tools round me mates agian :x ) and check behind stator plate.
Also forgot to say i filled up tank just after leaving work and used me mates oil,which he uses all the time and says is semi-synthetic. I use fully synthetic so i put 4% in tank. Could this be a problem?
Crap fuel or mates crap oil?
Any more help please.

Re: Loss of tickover and poor starting,help please.

Posted: Mon Aug 31, 2009 9:07 pm
by rog60
I would tend to go with some kind of fuel starvation on idle jet (blocked) especially if the engine will rev freely when throttle open............Just my thoughts

Re: Loss of tickover and poor starting,help please.

Posted: Tue Sep 01, 2009 11:48 am
by ove
checked mag seals and not blown,cleaned carb and seems ok, re-torqued head nuts slight slackness, about 2lb if that. Now emptied tank and will get some fresh fuel with my 2 stroke and see how we get on.

Re: Loss of tickover and poor starting,help please.

Posted: Tue Sep 01, 2009 11:10 pm
by ove
Well it starts,but won`t tick over at previous settings.I can get it to tick over by adjusting the cable. It always was on the rich side at tick over so i shall order a leaner pilot jet.
I have a nagging feeling it could be worse than a jetting problem, what would the signs of a piston ring failure be?

Re: Loss of tickover and poor starting,help please.

Posted: Wed Sep 02, 2009 7:23 am
by bristolmod
if you've got a ring breaking up/ broken up, you would hear it

Chris

Re: Loss of tickover and poor starting,help please.

Posted: Wed Sep 02, 2009 8:33 am
by ove
bristolmod wrote:if you've got a ring breaking up/ broken up, you would hear it

Chris
cheer chris
Would it be easy to spot the noise,as no obvious sounds coming from barrel. Also wouldn`t it run the same at all throttle settings?

Re: Loss of tickover and poor starting,help please.

Posted: Wed Sep 02, 2009 11:30 am
by bristolmod
Generally if a ring does fail, then it will do a lot of damage to the piston, head and barrel. You would certainly hear the noise.

It may be feasable that a ring could fail and parts of it be immediately spat out via the exhaust port, thus resulting in some loss of compression but with no "noise"- having said that IMO its very unlikely to happen that way.

Could possibly be a "stuck" ring in its groove causinl loss of compression and lack of power.

Whats the exhaust like? Are you sure its clear and not blocked?

TBH doesn't sound like a top end problem, but more carb related, but I fear a strip down will be needed to find out.

Let us know

Chris

Re: Loss of tickover and poor starting,help please.

Posted: Wed Sep 02, 2009 4:06 pm
by soullad
ove wrote:Well it starts,but won`t tick over at previous settings.I can get it to tick over by adjusting the cable. It always was on the rich side at tick over so i shall order a leaner pilot jet.
I have a nagging feeling it could be worse than a jetting problem, what would the signs of a piston ring failure be?
Poor starting, if at all - poor compression - crap tick over- alot of unburnt fuel / oil around end can / exhaust - lack of torque, noticeable when revving hard etc