Jcarteradams

It does seem to increase in power when I’m going along. It gets hairy! That sounds like a good shout. It’s an Amal carb but I’m sure that won’t matter too much!? Ive had a good inspection and it does seem as though there is a slight oil leak coming out from the spark plug. Would that cause anything such as air intake etc? The plug is in pretty tight so could there be an additional washer or something to help seal it? I will certainly take a good look at the float and pin, is there anything in particular that I need to look out for? Could the head gasket need replacing too? Thanks in advance

Good afternoon all I have a 76 Sherpa 350 and have been riding it on and off for a few months now. It’s my first bike but have spent many of hours getting to know it and from a non starter it works and runs well, apart from when I’m riding it will all of a sudden erratically just max out on the revs, similar to when she runs out of fuel! I then pull the clutch in and pull the kill switch, immediately. It tends to do this through the gears at any given time but usually when it’s in higher revs, and certainly keeps me on edge the whole ride. It’s like she has a mind of her own - the Bultaco is exactly the same! Is this anything to do with a blockage, how the carb is set up or the throttle? Many thanks in advance. Regards James

...Discovered that along time ago!

Oh really - that’s interesting to know. I believe mine uses the Amal MK11 carb, which needed a really good clean out. I was having some teething problems but now she’s running very well and just great fun to ride. Only thing at the moment is that after around 10 minutes of riding it smokes and burns the crud in the silencer exhaust, and it gets ridiculously hot, and also noticed some embers flying out. So turned it off and let it cool down and the smoke subsided. I guess it needs a good clean out. I hear caustic soda is good to get rid of the built up carbon in there? But over time I would like to get it up to the standard of yours - fully refurbish it, but for now I will keep it as it is and enjoy it without worrying about the paint work! Nice work, on to the next!

Looks great! Is this a 183 1976 350cc Sherpa? Looks very similar to mine. Well, mine doesn’t look as shiny but I’m sure they’re the same model. Great work, does she run ok? Best James

Evening all, I had the Sherpa running around the other day for a good few hours and it felt great. No issues really, with most of the previous questions rectified. However at the end of the session the bike ran out of fuel again so I topped it up and it didn’t start up again. Still getting a really strong spark, I thought i had got the fuel mixture ratios wrong so I emptied the tank and and also cleaned the carb and jets out for good measure. Still no start. So I thought must be the timing. However, when refitting the mag case last, I have somehow mixed up a longer screw and screwed it into the wrong position (bottom screw thread) of the mag case, which has unbelievably punctured the crankcase. I was obviously nearly in tears when I saw the oil spurting out, as I thought about checking the timing again due to the starting problems. Now I’m presuming this is the problem due to lack of compression, but it was running so now I’m not too sure. I guess I would like to know if this silly mistake can be simply repaired, without the need for a new crank case! Many thanks james

Yes - it was a fuel issue! As in, it ran out!! I’ve ridden it quite a bit today and Its running fine now. I was just worried I had broken something. I would love to get into trials riding. I’m based near Alysham in north Norfolk, could someone help and point me in the right direction? Shall I register the bike for the road too? thank you in advance, all very knowledgable and extremely helpful. This is my first bike so without this forum then I would of been a none starter. Thanks James

Evening gents, all was looking good. Started fine and just took it for a little spin around the garden and seemed fine. I thought I would just let it tick over for a couple of minutes whilst I sorted a few things out in the outhouse. Anyway, after around 5 minutes of it ticking over, the bike had a sudden surge and the revs maxed again, came back down and then up again before cutting out as I couldn’t get there in time to pull the kill switch. It now has a funny knocking noise when ticking over, and when kick starting, every 5 or 6 kicks or so feels like it’s getting stuck/jammed/air jam, and doesn’t fully kick down with a little puff of smoke out of the exhaust! Ive recently changed the exhaust gasket, so had all the exhaust off and wondered if the exhaust was full of old crud and now partially blocked after moving it around and the gasses going back in to the engine when trying to start up? It’s very smokey when it does start too. I will get a video later but any thoughts? Thanks in advance. James

Thank you guys. Great advise as always. Shes back up and running now and sounding good. Starts first kick too. Thanks for the help. James

Thanks for the replies. So Ive just spent a bit of time going through the ignition parts, and found that the woodruff key had sheared off yet again!! It turns out the crank case was pushing on to the crank nut, which was not the correct size and looks much deeper than the standard issue size, and has actually marked the inside of the case and was simply loosening off the nut, magneto wheel and therefore sheering the woodruff key. Correct nut and bolt ordered and new woodruff. Hope it will sit in the crank shaft and magneto wheel now ok though!!

Hi gents, so I reset the timing and all looked good. I got a good spark and so screwed everything back on and she started up, which was music to my ears. However as soon as I opened the throttle she spluttered and cut out. Which could be the carb settings, but it didn’t start back up again, and it was late so I left it for the morning. I’ve since tried again this morning and still no spark. I’ve tried the multimeter on the HT lead, and it’s not reading anything (hence no spark) - Is this a timing problem? Thanks James

Would the HT coil burn out at all? Will double check the lead is secure. No kill switch on, that’s waiting to be fitted. Thanks again james

Thank you everyone. I did remove the flywheel to find a sheered-off woodruff key. So that’s now been replaced along with new spark plug. However still not producing the spark. Time to re-set the timings and points as suggested. The vibrations from the throttle being fully open probably effected things. The nut for the magneto was lose too. Thanks everyone James

Spark must be really faint as I can hardly see it if anything. It’s a new spark plug and dry. Woodruff key is a good shout as I remember the guy who helped with resetting the points said it looked worn a few weeks back. It’s had a new condenser and Ht coils and was working perfectly though. And when it does fire up the kick start always shoots back and rattles around until I get hold of it when turning the kick start pedal inwards, then it’s able to sit there without the rattling. I will have a look tomorrow at the woodruff key and let you know. I hope it’s just that. It not could it be anything else inside - damage to piston or anything like that? many thanks James

Hi guys l have been having some great fun on my Sherpa 350 183 recently however I did a silly thing and left it outside for a few days and it got wet and stood there for a bit and so she didn’t start for a while. I re-cleaned the carb and renewed spark plug and it fired up BUT, the throttle cable was stuck on full whack and as I don’t have a kill switch on it yet it ran, full throttle for around 20-30 seconds before cutting out. I adjusted the throttle cable, and It re started moments later but then it came to a spluttering stop with a small backfire. Now it doesn’t start! I’ve tried a couple of new plugs, but nothing as of yet. Still plenty of compression too. Just wondering if it is a coincidence it’s not starting as I’ve recently refilled with new fuel, so I hope I’ve got the ratios right, I hope it is this rather than damage to something internally. Many thanks in advance James