garycox Posted July 17, 2019 Share Posted July 17, 2019 Hi all I’ve been using this daily for a few months now and covered 2,000 trouble-free miles. It has, however, developed an issue with loss of power. It’s difficult to describe but essentially at higher speeds/revs it’ll intermittently lose power in “surges” getting progressively worse until it gives up. It idles fine once started but can be difficult to get going again if it’s cut out rather than being switched off properly. I’ve replaced: - fuel filter - all fuel lines in the engine bay - fuel pump - coil - ignition leads ...and it seems to have made absolutely no difference. I really need it to be working by Friday; any suggestions?! Link to comment Share on other sites More sharing options...
Cavcraft Posted July 17, 2019 Share Posted July 17, 2019 Can only guess at duff plugs (breaking down under heat) or fuel evaporation. No pipes a bit close to the exhaust and have you tried new plugs as a matter of course in case the old ones are playing up? Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 Haven’t tried new plugs; the ones in it seem okay but I guess it’s fairly cheap to try that anyway - I only haven’t because I also need to buy a plug spanner as I have no sockets deep enough! Don’t think there are any fuel lines close enough to the exhaust for that but, again, a good thing to check! Link to comment Share on other sites More sharing options...
320touring Posted July 17, 2019 Share Posted July 17, 2019 Condenser? BeEP and alf892 2 Link to comment Share on other sites More sharing options...
lanciamatt Posted July 17, 2019 Share Posted July 17, 2019 Stuck float in carb,? Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 The float moves freely and fuel seems to be getting to the carb okay (there’s not much en route that isn’t new!) Condenser seems a popular suggestion; will probably try that next.., 320touring 1 Link to comment Share on other sites More sharing options...
320touring Posted July 17, 2019 Share Posted July 17, 2019 Good luck- they seem to be a fairly common failure point nowadays Link to comment Share on other sites More sharing options...
SiC Posted July 17, 2019 Share Posted July 17, 2019 What condenser is on it? Cheap ones are almost guarantee to fail. They'll take the points out with it. Link to comment Share on other sites More sharing options...
SiC Posted July 17, 2019 Share Posted July 17, 2019 I'd check fuel flow too. Might have the pump starting to fail. Link to comment Share on other sites More sharing options...
wuvvum Posted July 17, 2019 Share Posted July 17, 2019 When it loses power, is it a partial loss or is it as if the engine's been switched off? In my (admittedly limited) experience a failing condenser tends to produce the latter effect. If it's a partial loss it could be fuel related - might be worth bunging out for a cheap electric facet pump off eBay and bunging that in to see if it makes a difference. Link to comment Share on other sites More sharing options...
Tamworthbay Posted July 17, 2019 Share Posted July 17, 2019 Is the carb clean? For the first few months with me it needed weekly clean out sessions even with the filter, it would collect a very fine sludge in the bottom of the float bowl. Use seemed to solve it but worth checking (it stood a year before I recommissioned it, then I ran it a year before SF had it from me). Link to comment Share on other sites More sharing options...
SiC Posted July 17, 2019 Share Posted July 17, 2019 If you remove the petrol cap, does it help and/or let air in after a run? GBJ, chodweaver, Mally and 1 other 4 Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 Wuv - it’s significant; not quite “engine off” but not far from it. TB - I’m crap at carbs so haven’t fiddled with it; if it’s foolproof to check it’s worth a look I guess though; the float bowl’s definitely clear but I’ve not opened the “main bit”. Petrol cap off’s a free check at least... Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 SiC - I’ve just replaced the pump and no change... no idea what condenser’s on it but will change that too if I can pick one up tomorrow Link to comment Share on other sites More sharing options...
purplebargeken Posted July 17, 2019 Share Posted July 17, 2019 Usual culprit for this type of thing is coil or condenser breaking down as mentioned. I had the same issue with one of my 1300 Dollies and a 110 land Rover. I tend to run a decent Lucas 'sports' coil. 'Lecky components may be new but still shite. Link to comment Share on other sites More sharing options...
SiC Posted July 17, 2019 Share Posted July 17, 2019 Is there fuel still in the filter when this happens? Link to comment Share on other sites More sharing options...
Mr_Bo11ox Posted July 17, 2019 Share Posted July 17, 2019 Does it still have points or an elec ignition? I'd be straight on the points if it still has em. Link to comment Share on other sites More sharing options...
Three Speed Posted July 17, 2019 Share Posted July 17, 2019 I'd also suspect the coil. I imagine it may have a ballast resistor as I think Triumph were in the habit of fitting such things in the 70s. You could try shorting it out for a while and see if the problem goes away. Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 Still points - worth a try! Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 SiC - yes, still fuel in the filter Link to comment Share on other sites More sharing options...
SiC Posted July 17, 2019 Share Posted July 17, 2019 4 minutes ago, garycox said: Still points - worth a try! I reckon it's the condenser. The distributor doctor one is the only modern one worth having. This: https://www.moss-europe.co.uk/condenser-lead-25d-high-quality-gsc111hq.html?assoc=534797 (Other suppliers are available) Link to comment Share on other sites More sharing options...
SiC Posted July 17, 2019 Share Posted July 17, 2019 I made a video that basically explains the problem with the cheap ones: More details on this page: http://nonlintec.com/sprite/cap_failure/ LightBulbFun, garycox and purplebargeken 2 1 Link to comment Share on other sites More sharing options...
barrett Posted July 17, 2019 Share Posted July 17, 2019 Easy way to check is to put your hand on the coil after its happened. If the coil is hot it's been put under extra load or is breaking down which is probably a side effect of the condenser failing: coils don't tend to just give up, but condensers often do and this can have a knock-on effect on the rest of the ignition system. I'd try and find an NOS condenser and coil and swap both at the same time as no modern items are as good as originals in my experience. garycox 1 Link to comment Share on other sites More sharing options...
garycox Posted July 17, 2019 Author Share Posted July 17, 2019 Might have to make do with whatever I can find locally tomorrow - but then will track down a decent one ASAP. Link to comment Share on other sites More sharing options...
bunglebus Posted July 17, 2019 Share Posted July 17, 2019 Don't think it would cause the problem you describe, but it's always worth checking the oil in the dashpot on the SU carb too. Link to comment Share on other sites More sharing options...
garycox Posted July 18, 2019 Author Share Posted July 18, 2019 Dashpot oil is present and correct Link to comment Share on other sites More sharing options...
captain_70s Posted July 18, 2019 Share Posted July 18, 2019 New points and condenser would be my first point of call. Even if it transpires it isn't them a spare set is always hand to chuck in the glovebox. Doubt it is vapour lock, that is usually at its worst when the engine is idling hot and the fuel flow is lessened. I would say that don't always rule out a component once it's been replaced. I've had brand new starter solenoids and fuel pumps be DOA. Link to comment Share on other sites More sharing options...
garycox Posted July 19, 2019 Author Share Posted July 19, 2019 FUUUUCK So, we’ve now changed all of the above plus the condenser, rotor arm and plugs. Seemed like it was working but has got as far as Cuckfield (from Hayward’s Heath) and has died again. Exactly the same problem. It’s now being towed home by a friendly man who was passing on a tractor. AAARGH!! Link to comment Share on other sites More sharing options...
GBJ Posted July 19, 2019 Share Posted July 19, 2019 You may find that the points have closed up or something. Link to comment Share on other sites More sharing options...
purplebargeken Posted July 19, 2019 Share Posted July 19, 2019 Good call re: points gap. The fuel pump is pumping out a goodly amount of go juice is it? Have you taken off the dome bit on t he fuel pump to check the fine gauze filter? Link to comment Share on other sites More sharing options...
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