Please forgive my mechanical ignorance but I have not heard of a carbureted bike with an ECU or fuel pump. Is this so???Sorry for the delay, finally got a bit of time back on it again today and yesterday. I fitted a set of OEM coils and leads because they were changed not long ago, no difference.
Got a complete set of carbs off a running bike - exactly the same problem! As soon as I give any throttle at all it dies. I've just checked the static timing again and it looks perfect so I'm going for another rectifier and then thinking ECU or loom. I am going to look at fuel pump again because I noticed the diaphragm of the original pump is leaking now too
ECU is aka CDI or even ECM. All the same, whichever you want to call it, it controls ignition. Later ones with FI then control ignition and fuel.Please forgive my mechanical ignorance but I have not heard of a carbureted bike with an ECU or fuel pump. Is this so???
Compression test yet?Oh man I'm running out of ideas
I took it out for a spin, ran perfectly for the first 5 minutes. Started to warm up so I gave it a few revs and spluttered a bit then cleared itself and ran well. It was revving freely to about 7-8k rpm no problem.
Then it died again. Any kind of throttle and the engine gave up completely. I managed to limp home with the idle adjuster turned up so it was at about 3k rpm and the choke out to give a bit of fuel, not a pleasant journey at all.
It was popping and banging in the exhaust if I put the clutch in but all the plugs look slightly lean if anything. I put the CO meter on it and it's all over the shop, one minute rich and the other lean.
I'm toying with the idea of a second hand set of carbs to change everything in one go
Is that green can the fuel tank? If so, just for shits and giggles, use a remote tank without the fuel pump and hang it from eye level. We've been working on this so long I can't remember if we've done this. Even on the original bike, the fuel pump is under the fuel tank, and not trying to move fuel against gravity. It actually uses gravity as an assist.New fuel pump + lines from a clean can of fuel - still bad. Let it idle for a couple of minutes but any throttle and it died.
Changed the plugs for new again, still failed.
Went to take a video to show you guys before setting fire to it - all better! Watch it clear in the new video and I have attached an old one showing it about to die with throttle, also getting the most I can out the idle adjuster and about to stall on choke.
I'm wondering if it is fuel and it took longer than I thought to empty the float bowls?
Ian's comment :thumb::Could be on to something there. A bit of the old 'thinking outside the square'.:wink
Could be on to something there. A bit of the old 'thinking outside the square'.:wink
Ah, I understand. Just for interest, in the bike, the bottom of the sump is horizontal as is the crankcase split-line (crankshaft and clutch centres are on this line and horizontal).I'm afraid I can't compare to a bike because I've only had the car but if it was angle then it should have been there for the last 2-3k miles which have been perfect