I'm not sure how to check they are synced but they appear to both be "off" at exactly the same time but one side hits the full "on" point a fraction before the other so I guess they are slightly out. Yes it is a red accuspark coil. Replaced at same time as the accu dissy. Maybe I will dig out the old ones tomorrow since they worked fine...
I would defo try a coil first if you have a known good one, the one I had in this week had the coil and dissy fitted at same time, (not very long ago)dissy is still fine. Just another thought, if your carb was loose it may be wise to check for air leaks with some wd40 or similar at the gasket joins. If its letting in air it could be overheating and losing power. If you have a hex bar linkage on the dells, check the drop arms are operating at the same angles, if one is at more of an angle than the other it can throw the sync out over the operating arc.
Thanks. Good advice. I hadn't thought about using wd40 to check for leaks. Will have another look tomorrow.
Onr thing worth checking is for leaks in vacuum hoses as these often use the same brittle rubber as fuel hose. And my usual candidate for a loss of welly is losing a cylinder - spark plug lead just falling off.. Or a coil flashover .. or loose wires on the coil primary ..bad spade connectors etc. Loose rocker arm bolts, rocker sliding off the shaft and missing the valve.. But these all involve rough running too.. Straight loss of power can also be because the carburettor is flooding the engine because of a worn or jammed fuel metering valve in the carburettor float chamber fuel feed..
Just saying, but if engine still revs nicely is it possible it could be binding brakes or something non engine related? Happened to me and I thought engine but then was rear brakes.
I spose so. Had that too but a long time ago. Stop when you can if it does this and feel the wheels, if hot its a brake binding. Be warned they can be very hot if this is the case and you may lose the odd finger print if lingering too long!
Thanks for all your ideas. Starting through the list.... slowly! Changed coil back to previous one. No difference. Here's exactly how it drives: Absolutely fine in 1st and 2nd. In 3rd you start to notice it isn't accelerating properly. In 4th even worse. On a slight incline this was worse. I didn't try any steeper as it would be a snail. The wheels were definitely still cold afterwards. Also, I got out and went around the back blipped the throttle and if you held it high it would backfire. Not a massive one but definitely a bang. I have also adjusted the accel cable so it definitely (almost) maxes. Can't see any leaks with WD40, but can't see all around so will have to get a mirror. Awaiting a fuel filter. Have found old dissy that I know works so will do that soon. Hope I find the culprit soon as the engine is having to max out to get anywhere. Cheers!
When mine did this it was a split in the manifold boot so running super lean. You hear (rather than see) the leaks with WD40 as the revs rise while you spray. Sent from my iPhone using Tapatalk
Haven't acquired the tool yet. Although... There is no smoke, ever, and this test is for piston & ring trouble isn't it?
I'm beginning to suspect I'll have to take the carbs out but I realise it's bet to check through all the other things first. Can anyone remind me whether you can get twin dell drla 30(?)s out with the (1600) engine in?
Could be blocked jet, carbs out of balance , or like dicky says fuel ...dells are fussy 3- 3.5 psi Are you running a vac dizzy ? Timing , spark plug gap ...points or electronic ?
I've been thinking... That loose carb that I told you I tightened up... I bet the gasket only works once and it isn't sealing now even though I think it's tight. I might get a bit of time tomorrow in which case I will try and get the carb out and replace the gasket. It does seem pretty likely that will be it, as it was running fine before the carb loosened. When I put the engine back together last year, I used the manifold gaskets in the rebuild kit. I would have used them dry. Would anyone suggest using a gasket sealant as well this time? Also, I guess a drop of nut locking stuff wouldn't hurt, to stop it working loose again.