Author Topic: running problems again..UPDATE..now back to first kick from cold  (Read 3183 times)

Offline chicago

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hi fella's. went to start the bike today (a7 longstroke engine), bike started and then started missing, the left hand exauste was smoking. took the left hand plug out and was wet with petrol (had the same problem before on same cylinder), replaced the plug with a new one, ran ok for about 7 seconds and started missing again, tried to let it run for a minute or so to see if the missing might clear but it carried on missing, when i took the new plug back out it was wet and quite a bit hotter than the plug from the fireing cylinder. this confused me a bit as i would have expected the none fireing plug to be cooler than the fireing plug ???.
also when i was kicking it over to start it, i was getting a few small pops/backfires thru the carb.
maybe ive flooded it when going to start it (again) ??.
i did recently re set the tappets from 0.013 to 0.010 (originaly set to 0.010 when i bought it and started a lot easier)
as it was getting difficult to start from cold, after i set the tappets to 0.010 it did seem to start a lot easier and ran fine (could this be the cause).
i also had the rockers off recently, to re torque the head down, and noticed that at some point the exauste valve must have stuck as the push rod for said valve was slightly bent and had evidence on the top of hitting the edge of the rocker cup in which it sits.
while i had the plugs out i placed my thumb over each plug hole and there was enough compression to blow my thumb off the hole both sides, so would this rule out a sticking valve maybe ?? (i know not the best method to test compression)
ive got the points set to 0.012. (recently replaced)
the spark plugs set to 0.018.
and the valves set to 0.010
any advice much welcomed, cheers in advance, chicago
Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

Offline wilko

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Re: running problems again
« Reply #1 on: 24.11. 2012 20:49 »
Are you using the right length plugs? Have a look at the used ones to see if the tips have been hitting the piston and closing up. Are they 3/8th or 1/2 inch reach?

Offline chicago

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Re: running problems again
« Reply #2 on: 24.11. 2012 22:31 »
hi there wilko, cheers for the advice, yes using champion l82c with 1/2 inch reach. and no signs of them hitting the piston. there is a blue spark from both plugs when held against the barrel.
all the best fella, chicago
Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

Offline BSA_54A10

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Re: running problems again
« Reply #3 on: 25.11. 2012 10:55 »
Check the firing position on both plugs.
A lot of the magneto cams are not symmetrical so you either have to stone down the high side or set the timing to an "average" position.
Bike Beesa
Trevor

Online bsa-bill

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Re: running problems again
« Reply #4 on: 25.11. 2012 11:09 »
try a couple of old plugs, give them a clean put them in and try it
New plugs these days are a lottery
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline duTch

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Re: running problems again
« Reply #5 on: 25.11. 2012 11:53 »
Hiya Chicargo,- that's no good!
  I went on friday to collect some H4 35/35 bulbs-6volt, and got chatting with ol' mate, and one thing he put forth, is some plugs don't like maggies(or the maggies don't like the plugs?).
    He said inside the top of the ceramic insulator, which can (apparently) be unscrewed, is prone to corrosion, even on new plugs, but possible to rectify.
 Did you swap the plugs over, L> *eek*<R ? (just thought i'd stick my head in there and see if I could shoot meself as an after thought)- might make a difference?
 
Good luck, duTch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline a101960

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Re: running problems again
« Reply #6 on: 25.11. 2012 12:44 »
Quote
try a couple of old plugs, give them a clean put them in and try it
New plugs these days are a lottery
What Bill says is unfortunately only to true. Some time ago I bought and fitted a set of Bosch plugs to my car. The whole set was faulty. The car would start just fine and it would rev up without any load, but as soon as I attempted to drive the plugs would break down. The engine would miss and start to die. I refitted the old plugs and all was well. I have also bought and fitted new plugs to my BSA, and I have had similar problems. Sometimes the plugs would be OK for a few miles then fail, and sometimes the plugs would not fire even though they appeared to give a healthy spark when tested outside the combustion chamber. In the case of the BSA NGK plugs seem to be the worst offenders, and I have had similar problems with the odd champion plug, although in general the Champion plugs do seem to be less likely to cause trouble. Try also swapping the HT leads and plug caps. A good diagnostic procedure is to start the bike up in the dark to see if there is any HT leakage.

John

Online orabanda

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Re: running problems again
« Reply #7 on: 25.11. 2012 13:45 »
Check the air (choke) slide is open all the way; I have had the cable jump out of the lever, causing the air slide to not opebn all the way.

Had similar symptoms to yours, then noticed the cable issue, sorted it out, and the bike was good as gold!

Offline chicago

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Re: running problems again
« Reply #8 on: 25.11. 2012 15:20 »
hi fella's, cheers for the help. its now running again, i tried all your suggestions, first i changed the plugs for two old ones, kicked it over and it started, then after a couple of minutes started to die again. so tried re-kicking it but all i got was backfire so i took the pickups out and cleaned the slip ring, did notice a crack in the slip ring (will add photo in a bit), but nowhere near the brass contact points.
while i was there i took the ht leads out of the pickups and the ht lead and pickup closest to the rear wheel had water in where the ht leads fits into the pickup. cleaned and sprayed inside pickup with wd40.
i re-checked the points and pretty much 0.012 in both firing position
i put the plugs back in but this time swapped sides round. kicked it over and now running.
i think the issue is as quite a few people have suggested is dodgy plugs.
and with my bike running too rich on tick over wont help (wrong carb, 376/35). and no choke slide also.
ive also read on here i think, that with the ethanol/petrol petrol mix we are sold, once you flood your bike the plugs are knackerd ?.
anyway off to the shop for more plugs, fingers crossed.
once again, cheers for the help fella's. all the best, chicago
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Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

Online trevinoz

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Re: running problems again
« Reply #9 on: 25.11. 2012 20:34 »
Just a point, Chicago,
                                     Long stroke engines have valve clearances of 0.015".
I agree with others re plugs, I won't use NGK in my bikes, Champion and KLG seem to work OK for me.

Trev.

Online Brian

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Re: running problems again
« Reply #10 on: 25.11. 2012 22:40 »
Chicago I would pull the magneto off and get it reconditioned. If it has a crack in the slip ring that will be only one problem.

You can play around with plugs and carbies for as long as you like but if the maggy is crook it will never run properly.

The magneto is the "heart" of a british bike and if you want your bike to start and run correctly the maggy must be in good condition.

Offline metalflake11

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Re: running problems again
« Reply #11 on: 25.11. 2012 23:37 »
I fully concur with that Brian...........  Magneto's make my life simple, if I have a misfire on one side, I swap the leads over from brush to plug. If the misfire swaps side I replace the lot. If it doesn't change sides I check the points gap both sides and if that is ok, I take the mag off and give it to my prefered magneto repair specialist. A few weeks later I fit and forget for another 10-15 years! ...........I love 'em, all petrol engines have fancy pants ignition systems these days, black box for this, sensor for that, it makes you puke!......... But! when they put a petrol engine into a private plane and an ignition failure is terminal, it's a magneto they fit every time! *yeah*
All hail  *respect* the magneto!!!
England N.W
1960 A10
England

Offline chicago

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Re: running problems again
« Reply #12 on: 26.11. 2012 00:54 »
Just a point, Chicago,
                                     Long stroke engines have valve clearances of 0.015".
I agree with others re plugs, I won't use NGK in my bikes, Champion and KLG seem to work OK for me.

Trev.
cheers trev, i dont know if its possible to have a cam fitted from a later a7/a10 engine in my bike but it seems to start better/run smoother set at 0.010, when i got the bike they were set at 0.010, i did have them set to 0.013 for a while and it was a bit of a bugger to start. i am thinking im going to set them at 0.015 and see how it goes. all the best chicago.
Chicago I would pull the magneto off and get it reconditioned. If it has a crack in the slip ring that will be only one problem.

You can play around with plugs and carbies for as long as you like but if the maggy is crook it will never run properly.

The magneto is the "heart" of a british bike and if you want your bike to start and run correctly the maggy must be in good condition.
hi brian/metalflake11 cheers fella's, hope its not the magneto, firstly for the cost of refurb as im totaly skint (just blasted my last £25 on a colortune), and secondly i dont fancy my chances of getting the timming right without a load of hassle.

ive had a similar problem with the bike before with similar symptoms and turned out to be plugs first time, and points the second time, i do know the bike is running far too rich on tickover as always very sooty plugs.
plus the guy who i bought the bike off (gary) did say that the engine and mag had been reconditioned, vrm ltd in northwich (who gary bought the bike off) still had the add for the bike on there website after i bought it and it did metion on there that it had rebuilt engine and mag.
plus when i swapped the plugs over the smoke from the exauste also swapped sides, so im hopeing just a weak plug.
so lets hope its cool.
cheers fella's and all the best.
p.s i will let you all know how it all worksout with a update :)
Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

Online KiwiGF

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Re: running problems again
« Reply #13 on: 26.11. 2012 01:51 »
Hi Chicago, I think with the symptoms you have experienced (richness, sooty plugs) it would be worthwhile stripping and cleaning the carb, in particular identify then clean all the small air ways, jets, and fuel ways, also check the float is not catching on the bowl and being held down, or that the float has a leak, all this does not take long and does not cost anything apart from maybe a gasket and some carb cleaner.

My bike would not tick over properly, it has a 389 carb (more or less the same as 376) which was flooding and I found the tickler (which acts as a breather for the float bowl) was blocked, before that it was the fuel supply to the idle jet was blocked.
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1956 A10 Golden Flash  (1st finished project)
1949 B31 rigid “400cc”  (2nd finished project)
1968 B44 Victor Special (3rd finished project)
2001 GL1800 Goldwing, well, the wife likes it
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Offline Ted_Flash

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Re: running problems again
« Reply #14 on: 26.11. 2012 07:18 »
Don't forget to check for too soft mag pickups that smear graphite all over your slip ring.  Good pickups should have a slot running the full length of them.
Ted Wilkinson, Ramsbottom, Lancashire
1950 Golden Flash