Ok, I need some help please. I have taken a week off work to try and get to the bottom of this and I need as much help as I can get as it is doing my head in. Go to the bike, remove and clean the plugs and it starts first kick, takes revs and sounds sweet. Turn it off and try and start it and it has become a spitting back monster that when it starts is only on one cylinder (plug fouled). Clean the plugs,start it and go for a run it is great,until you stop and turn it off,then it is back to spitting back and a fouled plug. It's been on fire twice as it spat back into the bell mouths,which have now gone. New carbs,new valves and fitted with a Wassel ignition system. Where do I start? Please please help me as I am starting to hate this bike.
Spitting back can be a number of things
If megaphones are fitted you will get some of this, megaphonitis (yep it's a word) is when that spit back of fuel is drawn back into the cylinder and mixes with the fresh charge of fuel. But this is normally
A Mid range issue.
Too lean a mixture will cause spit back. Too lean of slide for example if it's low rpms.
Ignition timing too far advanced, the charge is ignited and if the valves haven't closed by that point you will get spitting back also.
Also check valve clearances.
sounds to me there is something amis with the electronic ignition pick up. ign switced off, connect meter set to ohms between 2 leads ,100 to 300 ohms ? and then check when it fails to restart. also check volt input to amplifier.
Did you check to be certain the choke is turning off?
Yep both chokes open fully and the accelerator slides opening together,the carbs are jetted as per the manual,needle positions as per the manual as well. There is a good flow of fuel. I will have a poke about the ignition system and make sure it is in order. Thanks for the ideas so far,keep them coming please.
hi willie, dont give up its a lovely bike!
is the battery ok and got good charge/charging when running
cheers
:) :) :)
Sounds ignition ish. May I suggest either an electronic or a possible coil problem. Quick check change your coils over and see if the problem still exists and if the fault changes sides. Not the most likely scenario but coils does funny things. In truth it sounds like ignition unit.
If you are going to throw it away let me know where??????????????????????////
Mike 8) 8) 8)
just been pulling the head off the rebuilt T100. done the bottom end, rebore, pistons etc. fired it up and its not running right, pull right plug lead and nearly stops, pull left and still running on right , a bit of spit back while restarting. then I noticed a weep of oil at the back of left cylinder. head now off and for some reason the new gasket is ok but somehow, I managed not to get the head skimmed. Why, I dont know, maybe it seemed flat enough when I checked it...
just a possibility? no exhaust leaking from gasketbut must be sucking air in and blowing back through carb.
Quote from: chaz on 17 May, 2020, 18:10
just been pulling the head off the rebuilt T100. done the bottom end, rebore, pistons etc. fired it up and its not running right, pull right plug lead and nearly stops, pull left and still running on right , a bit of spit back while restarting. then I noticed a weep of oil at the back of left cylinder. head now off and for some reason the new gasket is ok but somehow, I managed not to get the head skimmed. Why, I dont know, maybe it seemed flat enough when I checked it...
just a possibility? no exhaust leaking from gasketbut must be sucking air in and blowing back through carb.
A65 head is bad for getting it to seal correctly after fitting, i have had issues in the past as chaz says check for air leaks at cylinder head joint
:) :) :)
Sticky inlet valve. Before you rip anything to bits may I suggest that you simply put some upper cylinder lubricant into you tank and give it a run. See what happens. A Redex option is available and I've used it with some success.
Mike 8) 8) 8)
hi willie, i hope youve solved issue. but if not is it the same plug that fouls?
:) :) :)
Hi Willie.
Well you certainly have a great deal of advice/options. I think that we would all appreciate it if you would kindly do a follow up and let us know the outcome/
.
Thanks
Mike 8) 8) 8)