Having trouble with 1973 t140v bonnie. Have just fitted brand new wassel carbs and new boyer ignition system! Had full electronics tested and checked and all is working the way it shud except for the right side of the engine. Once started the right side is alot cooler than left. Spark plug becomes wet with fuel and upon inspection with a camera found a liitle fuel sitting on piston! When i shut the fuel off on right hand side the black smoke from exhaust stops and bike runs sweet and heats up perfect, then have too put fuel back on to fill carb. Obviously there is too much fuel going into the engine on that side. Been told its the float level. Anyone had this issue or have any idea if im missing something. Cheers Tiger
Float level is a possibility. Could also be the float needle not sitting/closing properly due to a speck of muck preventing it sealing completely. Whip the float bowl off to check for debris lurking in there. May also be worth having a word with the supplier to get their advice.
This is taxing my memory banks, but, are the cutaways in the slides identical? Also, are the circlips on the needles (the big long toothpick imposters) in the same position? 'Tis a long time since I played with this type of carb, so if I'm talking bollox (again) please excuse me ... it's me age!! Just as a complete afterthought, can you swap carbs from one side to the other to see if the problem goes with the carb or stays where it is? Are all the jets the same size? Still think a call to Wassel may be helpful if all else fails.
Hi Steve, thanks for your reply again. Im almost aure both cutaways are identical, and the circlips are in the same position. I have swapped over float bowls and floats and getting the same problem, my next step was to as u said swap complete carbs over but after working on this constant for last 2 days i stopped earlier and decided to try that tomorrow after work. It is really getting a pain as ive not been out a run longer than 30 mins haha. I do know that there is fuel getting into engine and not burning which results in the at side of the engine not sparking and therefor not heating the same as left side. I am hoping the problem will carry to other side when i swap carbs over so i know it is a carb problem for sure. If that is the case i will try contact wassell! Thanks again for the help steve
I assume you did not have this problem before changing carbs and ignition to Boyer? I also presume both carbs are jetted the same and have been set and balanced correctly?....very important to get pilot mixture screws (start with 1 and 1/4 turns out), and throttle "take off" points the same.....I do that with lollipop sticks on my Bonnie which has what I find to be faultless Mikuni carbs on. Also possible you simply have a "fouled" plug due to the above...when you fitted Boyer did you remove coils and fit one of the single, dual output type?....have you tried another plug or swapping them? I had plug fouling and "uneven fuel burning" issues with mine until I changed old Lucas E.I. for Pazon system with dual output coil....spot on now, with plugs always coming out that nice chocolate colour. Graham
just sayin.......... some years ago I had a brand new carb fitted on my vauxhall astra as the old one was u/s. the new one, even tho it was boxed and the label read correct, the jets were completely wrong and it was pissing fuel out. with the air cleaner off you could see the fuel spewing out. agree with the other guys too, you gotta check your sparks are good,it can be easy to go barking up the wrong tree
Hi graham. Thanks for the advice. Bike already had boyer system fitted. Also amal carbs. But bike had lay for 10years without being started so had an overhall. To date i have cleaned out tank, new fuel pipes, and cleaned carbs. Had trouble with carbs so just bought new wassell ones as read and heard they were worth it. also got new spark plugs, and champion spark plug caps. Ht leads tested and main coils tested (all good) and had witing all done to way it should be by a very experience auto electritian who loves old triumphs. When i fitted new carbs the right side was mis firing at times and was not running as smooth as left side. I got a 30 min run and bike cut out, turned out to be boyer system, so got new system fitted. Also one of the new champion plug caps went faulty (open circuit) so went back to old ngk plug caps which have been tested. And all electrics checked and swapped plugs and main coils over to eleminate possible electrical faults. Yday i swapped floats over, same thing. Then swapped float bowls and floats together, same thing. Tonight i swapped complete carbs over and now the problem is on the left side of engine, so it is definetly the right carb. I am going to take carbs off tomorrow night and take them apart to compare and see what the difference is. Hopefully i find something obvious. What should i look for in particular? Adjustment screws are set the same on both carbs so it has to be somethin inside the carb?? I am totally new to all this the past week but getting a rough idea from feedback here and youtube vids. Really appreciate the help graham
Forgot to say sparks are good and all is good with new battery. Still have to get the timing perfect but was put in position of previvious. Just the carb is running far too rich.
Now you have proved it is the carb, and if they were bought as a matched pair, i.e. same jets, needles, and slides....I would first of all suspect the float cut off needle is sticking or not seating properly, or the main jet needle is set too high. I don't know that particular carb, but on the old amals you could run a clear tube on outside of float bowl to check the level. Another possible cause, depending on the construction of carb, is the pilot jet has come loose and letting excess fuel by, this will be particularly obvious in tick over and first 1/4 throttle. Graham
Have swapped float bowl, floats and and float cut off needle round before i swapped complete carb and there was no difference. So must be pilot jet. These wassell carbs are a complete copy of the old amals, thats a reaseon i got them. It is mainly on 1/4 throttle so will check that tomorrow graham and let you know how i get on. Thanks again for info.
Just one other thing, I am fairly sure the pilot adjuster controls the amount of air and not fuel on the Amals, so another possibility is the airway is blocked (maybe with a sliver of swarf in the manufacturing process) If you have a compressor, give all the airways a good blast while you have carbs stripped.
Have now swapped complete carb round and prob was now on the other side so it is defo the carb. Tonight i have cleaned the carb out, jets everything and still no joy. Everything was clear. Sent the seller a message so see what he says. Very frustrating this
Hi camman. Got a replacement carb and is running better. But i now have puffs of white smoke coming from carb on right side. Someone told me its the intake valve needing re-seated?? So head off and check over weekend. The joys of an old bonnie eh haha.
The joys indeed .....but when set up right they are very reliable and a joy to ride IMO. I presume the tappet clearances are correct??...I would check this first, if too tight, it would account for blow back. If you are taking head off and going to re-grind the valve seats, check the head gasket is not blowing at all, or more likely between pots. Anneal it before refitting if it is solid copper, especially if it has thin gasket (0.050" or less) to up the compression As you may know the nine stud heads were a problem, but I suspect yours will be ten stud? If you have nine stud head I would advise stick to 0.060 thick gasket, and definately anneal it Meant to ask before, is the balance tube that goes between inlet manifolds ok...not split or leaking one end? Good luck Graham
hi did you find out what the problem was , I have fitted wassel carbs and my bonnie is running rich , tried settings, so descided to check the jets main was 200 instead off 190 and the needle jet is 5mm shorter
