Nomad
Member
- Messages
- 1,364
- Location
- North Devon (for how long?)
There have been a few folk here with bike projects, I've now managed to find time to work on a project that ran in the past but is now refusing to start.
The motor often fires up and tickover sounds good but it dies after a couple of seconds.
If this is a typical sign of a particular problem - let me know.
I know it needs sparks, petrol, and compression. It (seems it) has all 3 ... until it doesn't.
The bike has been running in the past so valve timing, compression etc were ok then. It has been stripped down and reassembled since so everything else is now suspect..
Ignition is a distributor with 12v twin coils (wasted spark), power is from a fully charged 12v car battery hotwired direct to the coils.
Timing has been checked & rechecked, Sparkplugs were fitted new before it went into storage (so are unused but not new).
Plugs have been removed & cleaned, they soon go black / sooty - no surprise given the amount of petrol I've fed it.
3 (old, unknown, untested !) monoblock carbs give similar results which makes me think the problem isn't the carbs. Pilot jets & floats were checked on all carbs before use.
Pouring neat petrol down the carbs / into the cylinders doesn't really help.
I have a very basic toolkit here (inc timing light & multimeter) but assume if I don't have it I can't get it, so getting extra tools or new parts is not an option.
Hopefully the problem is something obvious but I'm missing it ... suggestions welcome from folk who have experience of older Triumph Twins.
No need for general comments about "it needs fuel & spark" as I've already looked for those
The motor often fires up and tickover sounds good but it dies after a couple of seconds.
If this is a typical sign of a particular problem - let me know.
I know it needs sparks, petrol, and compression. It (seems it) has all 3 ... until it doesn't.
The bike has been running in the past so valve timing, compression etc were ok then. It has been stripped down and reassembled since so everything else is now suspect..
Ignition is a distributor with 12v twin coils (wasted spark), power is from a fully charged 12v car battery hotwired direct to the coils.
Timing has been checked & rechecked, Sparkplugs were fitted new before it went into storage (so are unused but not new).
Plugs have been removed & cleaned, they soon go black / sooty - no surprise given the amount of petrol I've fed it.
3 (old, unknown, untested !) monoblock carbs give similar results which makes me think the problem isn't the carbs. Pilot jets & floats were checked on all carbs before use.
Pouring neat petrol down the carbs / into the cylinders doesn't really help.
I have a very basic toolkit here (inc timing light & multimeter) but assume if I don't have it I can't get it, so getting extra tools or new parts is not an option.
Hopefully the problem is something obvious but I'm missing it ... suggestions welcome from folk who have experience of older Triumph Twins.
No need for general comments about "it needs fuel & spark" as I've already looked for those