countryman Posted October 18, 2020 Report Share Posted October 18, 2020 About a year or so ago I brought a Bultaco Pursang mk9, 1977 I believe. The bike under went a re build before I brought it and it does run great, the problem is it is a nightmare to start, the carb is a bing with no choke just a tickler on it , I have tried putting petrol down the plug hole to just priming the carb a bit but nothing works, when it does start it will just bust into life, the bike has a good spark and like I said when running it does go well. Any ideas what the starting problem is. Thanks Quote Link to comment Share on other sites More sharing options...
ditchman Posted October 18, 2020 Report Share Posted October 18, 2020 find it strange it has no choke........is it missing its trumpet and slide choke ? Quote Link to comment Share on other sites More sharing options...
daveboy Posted October 18, 2020 Report Share Posted October 18, 2020 I have an old lawnmower that is the same....In the end I just got a can of easystart and give it a squirt down the air filter... starts first time every time. Quote Link to comment Share on other sites More sharing options...
ditchman Posted October 18, 2020 Report Share Posted October 18, 2020 7 minutes ago, ditchman said: find it strange it has no choke........is it missing its trumpet and slide choke ? change carb for a zenith Quote Link to comment Share on other sites More sharing options...
sam triple Posted October 18, 2020 Report Share Posted October 18, 2020 Seen some people cover the bell mouth and give it a few kicks before there’s had fired into life Quote Link to comment Share on other sites More sharing options...
countryman Posted October 18, 2020 Author Report Share Posted October 18, 2020 No the carb is complete just has this tickler that you push up and Down, I have seen pictures on the internet Of them On Bultacos. i have had bikes like this back in the day but they were never hard to start, I must have kicked that thing over 70 times to day before it started, by then I was to knackered to ride it. 4 minutes ago, sam triple said: Seen some people cover the bell mouth and give it a few kicks before there’s had fired into life Not got anything like that on it unfortunately. Quote Link to comment Share on other sites More sharing options...
amateur Posted October 18, 2020 Report Share Posted October 18, 2020 Hold the tickler down until petroil drips out of the carb. Kick over twice with the ignition off to prime it. Throttle 1/4 open. Ignition on and kick smartly. If that fails, then try a one grade hotter plug and a squirt of easystart into the carb mouth or air filter. Carb or crankcase seals may be knackered - who knows if you didn't actually do the rebuild Quote Link to comment Share on other sites More sharing options...
countryman Posted October 18, 2020 Author Report Share Posted October 18, 2020 20 minutes ago, amateur said: Hold the tickler down until petroil drips out of the carb. Kick over twice with the ignition off to prime it. Throttle 1/4 open. Ignition on and kick smartly. If that fails, then try a one grade hotter plug and a squirt of easystart into the carb mouth or air filter. Carb or crankcase seals may be knackered - who knows if you didn't actually do the rebuild I will give that a go, another annoying thing with Bultaco is the kick start hits the foot peg when you kick down so you all ways feel your not getting a full kick. Quote Link to comment Share on other sites More sharing options...
amateur Posted October 18, 2020 Report Share Posted October 18, 2020 39 minutes ago, countryman said: I will give that a go, another annoying thing with Bultaco is the kick start hits the foot peg when you kick down so you all ways feel your not getting a full kick. Can you fit a folding footrest? Quote Link to comment Share on other sites More sharing options...
Saltings Posted October 18, 2020 Report Share Posted October 18, 2020 1 hour ago, amateur said: Hold the tickler down until petroil drips out of the carb. Kick over twice with the ignition off to prime it. Throttle 1/4 open. Ignition on and kick smartly. If that fails, then try a one grade hotter plug and a squirt of easystart into the carb mouth or air filter. Carb or crankcase seals may be knackered - who knows if you didn't actually do the rebuild what he said also clean the points with a fine sandpaper if that works change the condenser as fowling the points up also check ignition timing app 3mm btdc Quote Link to comment Share on other sites More sharing options...
ditchman Posted October 18, 2020 Report Share Posted October 18, 2020 blow into the fuel tank..get it to pressuize so it super floods...... Quote Link to comment Share on other sites More sharing options...
point and shoot Posted October 19, 2020 Report Share Posted October 19, 2020 Low compression? Quote Link to comment Share on other sites More sharing options...
hodge911 Posted October 19, 2020 Report Share Posted October 19, 2020 I had a bultaco sherpa in early 80s that was a right pig to start . Tried different grade plugs amongst everything else we could think of .... ended up shifting it on .... But in hindsight I wished I'd kept it Quote Link to comment Share on other sites More sharing options...
amateur Posted October 19, 2020 Report Share Posted October 19, 2020 Giving a little more thought to this...... 1. After you have been trying to start it, when you remove the sparkplug, is it wet with petroil or dry? If wet, leave the plug out and kick the bike over with a wide open throttle to clear the overfuelling from the cylinder and crankcase. Replace the plug with a clean, preferably hotter plug and try again. If dry, spray easystart down the plug hole, replace the plug and try again. 2. As written above, if you have a nice fat spark, recheck the ignition timing. If the spark is a bit weak, clean and gap the points and check the ignition timing. 3. If all the above fails, put a fuzzy photo on eBay. Advertise it as a "Desirable Classic barn find, not run for a while" and use the proceeds to buy a proper English fourstroke that you can spend thousands on and tear your hair out, but will sound much better. Quote Link to comment Share on other sites More sharing options...
countryman Posted October 19, 2020 Author Report Share Posted October 19, 2020 1 hour ago, amateur said: Giving a little more thought to this...... 1. After you have been trying to start it, when you remove the sparkplug, is it wet with petroil or dry? If wet, leave the plug out and kick the bike over with a wide open throttle to clear the overfuelling from the cylinder and crankcase. Replace the plug with a clean, preferably hotter plug and try again. If dry, spray easystart down the plug hole, replace the plug and try again. 2. As written above, if you have a nice fat spark, recheck the ignition timing. If the spark is a bit weak, clean and gap the points and check the ignition timing. 3. If all the above fails, put a fuzzy photo on eBay. Advertise it as a "Desirable Classic barn find, not run for a while" and use the proceeds to buy a proper English fourstroke that you can spend thousands on and tear your hair out, but will sound much better. Tried what’s been suggested this morning except timing, the plug is wet when I take it out after trying to start, my left leg is now much muscular than my right. When I do get it started it runs great but I can not get it to tick over as well, adjustment of the carb just makes it run to fast and the throttle response goes, it just revs up and slowly dies down. I am close to booking it in to some off road bike shop and let them go over it, may be the carb is worn. Quote Link to comment Share on other sites More sharing options...
amateur Posted October 19, 2020 Report Share Posted October 19, 2020 (edited) Good luck with finding anyone who understands classic motocrossers and particularly Bing carburettors! If the carburettor is original and the throttle slide has any play, consider it to be knackered. Were it mine, I would be talking to Burlen and replacing the Bing with a new Amal. They can supply a correctly sized and jetted Amal at probably less cost than trying to sort out the Bing. Back in the early 80s, I had a Rickman Zundapp and swapped out its knackered Bing for the Amal equivalent and it ran like a demented clockwork mouse. Edited October 19, 2020 by amateur Quote Link to comment Share on other sites More sharing options...
Saltings Posted October 19, 2020 Report Share Posted October 19, 2020 been around old engines a bit push tickler until floods visible fuel ignition off kick over 2 or 3 times ignition on no throttle kick over first or second kick should start only use the highest octane fuel check float in carb not sticking or contaminant holding it open modern day fuel has ethaline blend which ******* up rubber hoses and seals makes everything sticky and chewing gum like your idle mixture is an air screw tick over nicely wind in 1/8 turn main running the needle can be adjusted up or down for the right mix plug color a tan brown black ritch white lean hope this works if not pm your number and weal have a chat Quote Link to comment Share on other sites More sharing options...
amateur Posted October 20, 2020 Report Share Posted October 20, 2020 (edited) 23 hours ago, countryman said: Tried what’s been suggested this morning except timing.......... That one is critical. It is said that 90% of carburetion problems are ignition related. 😁 Edited October 20, 2020 by amateur Quote Link to comment Share on other sites More sharing options...
ditchman Posted October 24, 2020 Report Share Posted October 24, 2020 once it is running and then you stop it.....is it still hard to start when it is warm/hot ? Quote Link to comment Share on other sites More sharing options...
countryman Posted October 24, 2020 Author Report Share Posted October 24, 2020 1 hour ago, ditchman said: once it is running and then you stop it.....is it still hard to start when it is warm/hot ? Yes it is, I have someone coming next week who is a lot more knowledgeable than me so hopefully he will throw some light on the problem. Quote Link to comment Share on other sites More sharing options...
ditchman Posted October 24, 2020 Report Share Posted October 24, 2020 then start with the timing ,...get that right....then the carb.....im sure you will get it right in the end.....let us know what the outcome is ... Quote Link to comment Share on other sites More sharing options...
countryman Posted November 7, 2020 Author Report Share Posted November 7, 2020 On 24/10/2020 at 11:00, ditchman said: then start with the timing ,...get that right....then the carb.....im sure you will get it right in the end.....let us know what the outcome is ... Timing is out. After lock down I am going to get the timing and carb jets sorted. Quote Link to comment Share on other sites More sharing options...
sheene7 Posted November 9, 2020 Report Share Posted November 9, 2020 (edited) If you're planning to keep the bike, do yourself a favour and fit a Mikuni carb on it. I've got a Bultaco and a Husqvarna that both had Bing carbs on them, they now have Mikuni carbs fitted and are better for it. They usually start second or third kick even after standing for a few weeks. Dave Renham is your man for any Bulty parts https://www.inmotiontrials.com/product/mikuni-pursang-motocross-carb-complete/ Edited November 9, 2020 by sheene7 Quote Link to comment Share on other sites More sharing options...
countryman Posted November 11, 2020 Author Report Share Posted November 11, 2020 On 09/11/2020 at 20:23, sheene7 said: If you're planning to keep the bike, do yourself a favour and fit a Mikuni carb on it. I've got a Bultaco and a Husqvarna that both had Bing carbs on them, they now have Mikuni carbs fitted and are better for it. They usually start second or third kick even after standing for a few weeks. Dave Renham is your man for any Bulty parts https://www.inmotiontrials.com/product/mikuni-pursang-motocross-carb-complete/ Thanks I’ll keep that. Quote Link to comment Share on other sites More sharing options...
powler Posted November 11, 2020 Report Share Posted November 11, 2020 Just browsed through this thread and forgive me if already mentioned, but could the petrol have gone off? Mick Quote Link to comment Share on other sites More sharing options...
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