Not running smooth
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grahamcamm
- Posts: 42
- Joined: Sun Jun 21, 2009 6:02 pm
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Not running smooth
I have a silver century plus and have recently stripped the whole fuel system. It now starts great, however, on Friday I took it out for a good run. What's happening now is that it runs like a sewing machine for about 5 mins then seems to miss fire very rythmatically for about 10 seconds then runs fine again for another 5 mins or so. I know it's a single cylinder but the only way to describe how it runs when not smooth is as if it's a twin cylinder running on one, thats how rythmatically it runs. It does this at all speeds. I have put it in a wheelie bin to check at home and I have noticed that water is dripping from the right hand side of the head gasket ever so slightly and increases as the revs increase. Is this the head gasket on its way out or do you think the running problem is something else. I used only normal 2 stroke oil on Friday but would that make a differrance. Thanks
It sounds as though it is "four stroking" ... only firing on alternate revolutions.
Probably goes ok initially when you increase the power but then starts again when it settles or if you reduce the power.
It is a symptom of a rich mixture.
Yours is a Villiers carb ?? Try winding the needle down a little bit at a time, but you'll probably start to get symptoms of being to weak, like need the choke for ages or the odd "lean sneeze" before you cure it totally.
Oh no its not a Villiers !
FWIW my Featherweight does it so badly now its converted to 25:1 that the needle is down about 3 turns from "normal" to correct it!
The 2T oil is a bit heavier than TCW so likely to have the opposite effect if anything ... Perhaps.
Probably goes ok initially when you increase the power but then starts again when it settles or if you reduce the power.
It is a symptom of a rich mixture.
Yours is a Villiers carb ?? Try winding the needle down a little bit at a time, but you'll probably start to get symptoms of being to weak, like need the choke for ages or the odd "lean sneeze" before you cure it totally.
Oh no its not a Villiers !
FWIW my Featherweight does it so badly now its converted to 25:1 that the needle is down about 3 turns from "normal" to correct it!
The 2T oil is a bit heavier than TCW so likely to have the opposite effect if anything ... Perhaps.
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grahamcamm
- Posts: 42
- Joined: Sun Jun 21, 2009 6:02 pm
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Run it on the correct mixture for the carb jets or needles fitted.
the main reason for converting them I think is to make them a lot less messy to handle. A little more environmentally friendly too.
If yours is supposed to be running on 10:1 changing back may solve the problem. Can but try!
Is that a two jet bottom feed Amal or the 416 single jet ? The latter ??
There used to be lots of info on the website about the different carbs but seems to have been lost. Even what should produce a diagram of the two jet Amal produces a 416
the main reason for converting them I think is to make them a lot less messy to handle. A little more environmentally friendly too.
If yours is supposed to be running on 10:1 changing back may solve the problem. Can but try!
Is that a two jet bottom feed Amal or the 416 single jet ? The latter ??
There used to be lots of info on the website about the different carbs but seems to have been lost. Even what should produce a diagram of the two jet Amal produces a 416
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grahamcamm
- Posts: 42
- Joined: Sun Jun 21, 2009 6:02 pm
- Location:
If the carb has not been converted to 25:1 ie still has size 45 or 50 power jet fitted then there are perhaps two options. Either change the jet to a size 40 or run on a 10:1 mix.
Bearing in mind the comments on the website about taking care not to damage the carb body and the need to find or improvise a box spanner/key the latter has obvious attractions.
If the carb has been converted to 25:1 then experimenting with somewhat oilier mixes may be worth trying. Cannot think of any other possibilities.
All assumes of course that everything else is right. No suggestion that the float is not controlling the fuel level correctly ie not flooding
Maybe someone else will have some ideas.
Bearing in mind the comments on the website about taking care not to damage the carb body and the need to find or improvise a box spanner/key the latter has obvious attractions.
If the carb has been converted to 25:1 then experimenting with somewhat oilier mixes may be worth trying. Cannot think of any other possibilities.
All assumes of course that everything else is right. No suggestion that the float is not controlling the fuel level correctly ie not flooding
Maybe someone else will have some ideas.
Seem to have forgotten the head gasket here, if water is leaking out of the head gasket then I would say that yes it is on the way out and will need sorting, it is unlikely to run correctly in that condition, water getting into the cylinder will no doubt cause misfiring of some kind or another.
Make sure it really is leaking before you attempt a repair though and look at the advice on main site for head removal, if you are lucky its easy, if you are like the rest of us it ain't and involves heat etc
Make sure it really is leaking before you attempt a repair though and look at the advice on main site for head removal, if you are lucky its easy, if you are like the rest of us it ain't and involves heat etc