Pdv Posted May 9, 2022 Report Share Posted May 9, 2022 Hi aĺl Engine will not fire up. Fitted all new electrics, points plugs etc and new fuel pump. Electrics fine as strong spark at plug. Fuel pump working fine as checked fuel at the pipe entering the carburettor and fresh fuel lnto carburettor float chamber. The engine with this carburettor used to start first time but has not been started for a couple of years. Fresh fuel not e10 into an empty tank so no contaminated fuel. Diaphragm is in good condition and all moving parts sèem to move freely. Manual says to tune the carburettor the engine has to be warm, so that's a lot of help. I am obviously missing something basic, but am at a loss as to what. Also bought some Easy Start and the engine fired but did not run, so assume that the plugs are working OK. Any help would be much appreciated. Thanks Steve Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 9, 2022 Report Share Posted May 9, 2022 Timing is possibly wayyy off. You're getting a spark but not at the right place. Try moving the dizzy in increments and try again. Link to comment Share on other sites More sharing options...
johny Posted May 9, 2022 Report Share Posted May 9, 2022 Can you smell fuel from the carb or even see it wet in its mouth? Link to comment Share on other sites More sharing options...
NonMember Posted May 9, 2022 Report Share Posted May 9, 2022 Has the carb been worked on at all? Or has it been sat for a couple of years with stale fuel in it? If the latter, it's probably gummed up and will need dismantling and cleaning. It's not a hard job on Strombergs. When you put it back together (so we're now at the former case) you need to set an "initial state of tune", which is all they ever got at the factory. Wind the jet up to flush with the bridge, then three whole turns down. That should certainly be good enough to get it started on choke, and then warm it up for final adjustment. Link to comment Share on other sites More sharing options...
dougbgt6 Posted May 9, 2022 Report Share Posted May 9, 2022 "Easy Start" is good stuff, I believe in Australia it's called "Start ya Bastard!" If it's trying with Easy Start timing and spark are near right, but if not started for a long time the manifold gasket may have deteriorated. This was my problem, Easy Start made it try, but an air leak at the manifold and you've got little chance. Doug Link to comment Share on other sites More sharing options...
Pdv Posted May 9, 2022 Author Report Share Posted May 9, 2022 Hi non member It has been sitting dry and garaged so it may not need cleaning, and as I said it all seems to all move OK, but something is not right so I will give it a clean and set it up as said. Was hoping that the manual would have said about an initial state of tune. Thanks Steve Link to comment Share on other sites More sharing options...
NonMember Posted May 10, 2022 Report Share Posted May 10, 2022 10 hours ago, Pdv said: Was hoping that the manual would have said about an initial state of tune. Actually the official WSM does - I checked it to remind myself whether it was two or three turns - but it's fairly well tucked away in the text. Link to comment Share on other sites More sharing options...
Pdv Posted May 10, 2022 Author Report Share Posted May 10, 2022 Hi Nonmember, Thanks for that will find it. Interestingly the Haynes manual has a chapter on what to do with an SU carb that won't start. Thanks Steve Link to comment Share on other sites More sharing options...
Stratton Jimmer Posted May 10, 2022 Report Share Posted May 10, 2022 3 minutes ago, Pdv said: Interestingly the Haynes manual has a chapter on what to do with an SU carb that won't start. Chuck it in the bin and fit a Stromberg! Link to comment Share on other sites More sharing options...
chrishawley Posted May 10, 2022 Report Share Posted May 10, 2022 12 hours ago, Pdv said: Fuel pump working fine as checked fuel at the pipe entering the carburettor and fresh fuel lnto carburettor float chamber. Did that include direct observation of the fuel level in the float chamber? i.e float chamber reomved for inspection? I'd be guessing that an uppermost cause of non-start after work on fuel lines is an obstructed needle valve in the carb due to general detritus or rubber shards. Easy diagnosis but does involve removal of carb and partial disassembly. If carb has not been apart in years then a new float chamber gasket will be needed on reassembly. Does throttle air valve fall with a nice click on to the bridge? If not, and the top cover has been removed recently and all is clean, slacken the four retaininng screws and gradually and sequentially retighten, repeatedly checking for free fall of the valve. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 10, 2022 Report Share Posted May 10, 2022 with the air clear off lift the stromberg/Su piston and let go it should drop qickly with a nice clunk as it bottoms out if its stiff then raise the jet adjuster to be level the jet with the top of the jet holder now centralise the jet undoing 1/2 turn (the bigger nut) drop the piston and give the jet a light tap test the drop gives a clunk nip up the big nut from flush drop the jet adjuster 3 turns (( often 2 is enough) top up the dashpot with engine oil either make do make sure the choke is fully operating by su dropping the jet and CD the ramp does block the intake on CDS the choke valve is rotating that covers most of the basics , nothing difficult make sure the diaphragm is located and the two holes in the piston do face the engine if the diaphragm is wrinkled a wash in petrol will revert it to size Pete Link to comment Share on other sites More sharing options...
NonMember Posted May 10, 2022 Report Share Posted May 10, 2022 8 minutes ago, chrishawley said: Did that include direct observation of the fuel level in the float chamber? i.e float chamber reomved for inspection? That's a bit trickier on a Stromberg than an SU, because the chamber is below the carb and has a big hole in the bottom for the jet adjuster to pass through. Removing it guarantees it's empty. What you can do, and is worthwhile, is to put a tub under the carb, take the chamber off (five or six long screws), then operate the fuel pump and check that fuel flows all the way past the valve. 1 Link to comment Share on other sites More sharing options...
Pdv Posted May 10, 2022 Author Report Share Posted May 10, 2022 Hi All, Thanks for your replies, as Pete says the basics are not difficult so it is back to basics. I have removed the carburettor and will check it all out and set it up as described. Thanks Steve Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 11, 2022 Report Share Posted May 11, 2022 take care with float gaskets on stroms as the kits often have a multitude of gaskets they all look similar but some evolution means some corners have changed and fit the wrong one and you make a nice leak , so tip is check the one you replace is an exact relpica by shape/contour or it will leak you dont need to remove the carb to set most of this up , easier to set the float heght if needed all other settings can be done On car Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted May 12, 2022 Report Share Posted May 12, 2022 Steve, Something we always recommend to look at when asked about Strombergs is: Carburetors — Buckeye Triumphs But not this time, apparently They are 175s, but essentially the same as 150s. In 3 episodes they explain disassembly/theory, overhaul and re-install/setup. Doug Link to comment Share on other sites More sharing options...
daverclasper Posted May 12, 2022 Report Share Posted May 12, 2022 On 10/05/2022 at 10:03, NonMember said: What you can do, and is worthwhile, is to put a tub under the carb, take the chamber off (five or six long screws), then operate the fuel pump and check that fuel flows all the way past the valve. That's a good idea, never heard it before. Some repair books (not W.S manuals), give some tips and tricks, though would love a book with all that non official insider Knowledge. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 13, 2022 Report Share Posted May 13, 2022 there are some ideas floating about in the club back room to develop a wiki linked how to we can infill with good ideas searchable and forum linked so Dave keep a watch out this may..or may not develop it is just an idea but sounds a good one Pete Link to comment Share on other sites More sharing options...
Badwolf Posted May 13, 2022 Report Share Posted May 13, 2022 Pete - That is indeed a very good and useful idea. Link to comment Share on other sites More sharing options...
daverclasper Posted May 13, 2022 Report Share Posted May 13, 2022 YES Link to comment Share on other sites More sharing options...
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