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Starting problems Avanti

PostPosted: Wed Oct 28, 2015 6:27 pm
by Blaginit
Hi set timing 17 deg but magneto is all of the way in elongated holes fully to the r/h side it is an Avanti 225 and carb was jetted needled etc by Ron Moss so it should not be far of the mark but I've put a cable choke on and can't find out if choke just needs to lift of seat or does it have to travel right up the chamber to operate correctly please help it started once after about 20 kicks I've got good spark please help

Re: Starting problems Avanti

PostPosted: Wed Oct 28, 2015 6:42 pm
by Adam_Winstone
Choke is normally best if the plunger only lifts up about half way as this ensures that you have enough cable play for it to seat fully when you turn it off, otherwise you can run into issues where the plunger doesn't seat fully and it makes it impossible to set jetting correctly.

What flywheel and stator are you using, if full rotation on elongated slots only gets you to 17 dbtdc? Is this a cheap Indian flywheel that might have the wrong centre boss in it (points poss rather than electronic boss)?

Normally, such starting issues on a new build are to do with a lack of fuel getting into the combustion chamber (a little squirt/dribble of fuel in through the spark plug hole can start it and help to identify the issue). Timing being a mile out, often the result of a sheared woodruff key, is another possibility.

Best of luck with it.

Adam

Re: Starting problems Avanti

PostPosted: Wed Oct 28, 2015 6:48 pm
by MickYork
need a bit more info'

What type of carb' ?
Open mouth or filter ?
Is it a new build or has it been running ?
New fuel or some that has been in the tank a while ?

the more information the better.

If it's a PHBH have you a 70 choke jet ? the choke doesn't have to lift by much, you can see it lift by looking in a small hole in the R/H side of the carb mouth (a torch makes it easier to see)

Re: Starting problems Avanti

PostPosted: Wed Oct 28, 2015 7:08 pm
by Blaginit
Hi all its new build 30mm delorto bgm lightened flywheel 12volt ac with one 12volt dc connection I've had it running but it took 20 to 30 kicks and it did run well and re started its just to much for my old knees

Re: Starting problems Avanti

PostPosted: Wed Oct 28, 2015 7:08 pm
by Blaginit
Hi all its new build 30mm delorto bgm lightened flywheel 12volt ac with one 12volt dc connection I've had it running but it took 20 to 30 kicks and it did run well and re started its just to much for my old knees

Re: Starting problems Avanti

PostPosted: Wed Oct 28, 2015 7:17 pm
by MickYork
try starting with hand or cloth over the carb. if it starts easier you've either an air leak (too much air) or not enough fuel (choke not big enough/blocked jet/other)

Re: Starting problems Avanti

PostPosted: Wed Oct 28, 2015 9:05 pm
by Blaginit
MickYork wrote:need a bit more info'

What type of carb' ?
Open mouth or filter ?
Is it a new build or has it been running ?
New fuel or some that has been in the tank a while ?

the more information the better.

If it's a PHBH have you a 70 choke jet ? the choke doesn't have to lift by much, you can see it lift by looking in a small hole in the R/H side of the carb mouth (a torch makes it easier to see)

just checked choke it is lifting but not clearing the hole just under half way do you think this could be the problem

Re: Starting problems Avanti

PostPosted: Thu Oct 29, 2015 10:23 am
by coaster
One of the most basic mistakes when starting a Lambretta (or any engine really) is to twist the throttle as you kick it. You need to turn on the choke and petrol and keep the throttle closed during the kicking process. If it doesn't fire after a couple of kicks then it is probably an air leak. You can check the readings on your stator but personally I don't think it would be starting at all if it was a weak or intermittent spark.

Re: Starting problems Avanti

PostPosted: Sat Nov 07, 2015 7:03 am
by Raveydavey
Is fuel getting through?

Check the plug get wet after kicking it over a load of times. If it's dry there's your problem. If it's soaking, it' could be flooding. Try kicking it a couple of times with throttle fully open.