Hi . Hoping someone can help, before i loose my rag and throw the teddy out of the pram.
I have a 1970 Bsa B25 Starfire which is very difficult to start.i have a good spark, but its taking an age to prime the plug with petrol.
Carb fitted is Amal 928 concentric with all factory settings.
Carb has been rebuilt with new throttle slide,pilot air screw,throttle stop, the only item i have not replaced is the throttle needle.
I can take up to 25/30 kicks before its fires ,then running and restarting no problem.
When you remove the spark plug having primed/kicked you would expect the plug to be wet, not the case. Clutch adjusted so engine not slipping whist starting/running.
Yes the bike has been idle for a little while , so how can i improve the starting technique?
Bike performs well on the road, and very happy once its going
any advise would be helpful. cheers.
mike.
Are you using the tickler?
It sounds like it might be too weak to start.
Are you holding the tickler down 'til you see fule comimg out of the vent beside it?
Good luck. I can really empathise with you havimg been there myself. Believe me, you will crack it with the help available on here and your currents frustarations will sonn be a distant memory pal.
thanks dean for your input.
yes using the tickler, and fuel coming out.
regarding your other comment. to weak to start? it got me thinking , i have not cleaned the pilot jet which is situated behind the pilot air screw , so with that cleaned and re set could make the mixture richer. Hoping that make sense. bfn mike
Well another afternoon in the garage with GOOD results i hope. Carb stripped and cleaned again but cleaning the pilot jet this time around, and then cleaned spark plug and reset, and then drained refilled system with new fuel.
Results. Now staring 3rd /4 the kick. Now just wants finer tuning to obtain a nice tick over etc. Bike pulls well.
Did you clean the two very small pilot drillings with high pressure carb cleaner. Have a look at YouTube, those drillings always get missed, don't squirt it in your eyes when you do it.
HI. When quirting carb cleaner into the pilot air screw hole, fluid came out of those two small holes which are located in the base of the carb. cheers
HI.
Poor starting continues, when bike eventually fires up. it runs great on the road and sticks over well.
Question.
If i fit electronic ignition would it improve the starting of the bike.? any recommendations of maker
bfn
mike
Electronic ignition will eliminate the ignition advance unit as a source of trouble. The need for a battery in top condition is perhaps even greater than for points though.
Even if you have a good spark seen this is perhaps not the case in the cylinder where the pressure is higher. I suggest you check the battery voltage at the coil. If possible try another coil before electronic ignition.
Electronic ignition will help. I have the Wassell one on my Starfire. Easy to fit and works a treat. Starts 1st/2nd kick.
I've also noticed on mine that it needs 'a good flooding' on the carb. If I release the ticker as soon as fuel drips it wont start. I need to hold it down for a half second or so. Worth a try.
Trouble with this sort of thing is that it could be a number of things.
Keep us informed and good luck.
The tickler is an Amal Wonder thing. My A65 always started at first kick after a good tickling.
If you get fed up with the poor starting - I'll take the bike off your hands for a small fee!
Joking apart if the standard ignition set up is ok,starting should not be a problem . When I had one a few years ago, the bike started first or second kick. One component that often performs badly is the condenser (capacitor). I have changed them in the past and have been surprised the difference it made.
If does sound to be carb related. Have you checked the float level?
Go back to basics and check everything.
Please let us know.
I agree about the condenser. Think it is a part that suffers from old age even if the machine hasn't been used. Which means that even NOS condensers should be treated with a shadow of a doubt.
Haven't seen any specifications about the capacitance for the Lucas condensers. Does anyone know?
From what I have read, "old " condensers seem to have a shelf life and new ones from our oriental friends often have no life at all, it seems, unless you are lucky.
Some years ago, certainly with cars, aftermarket electronic ignition systems were looked on with a bit of suspicion because of the doubt of the electronics reliability..."you are better off with points and condenser, dead reliable" used to be the mantra. Unfortunately with unreliable condensers floating about this is no longer true. And rotor arms too can give trouble, with electronic systems or not.
My old Midget has electronic ignition but I carry a complete conventional, tested, distributor in the boot along with a strobe timing light should I need to change it when out on the road.
Trying a different condenser couldn't do any harm, preferably perhaps a German or British one if you could be sure it didn't come from the far east.
I noticed that Lucas has taken up condensers for classics. https://www.lucasclassicmotorcycle.com/prod_details.html?sa=LU4
Quote from: LightningAndStarfire on 11 Mar, 2020, 10:13
I agree about the condenser. Think it is a part that suffers from old age even if the machine hasn't been used. Which means that even NOS condensers should be treated with a shadow of a doubt.
Haven't seen any specifications about the capacitance for the Lucas condensers. Does anyone know?
My old Viva Hb stopped one day, living in the country I cycled 10 mile round trip to the parts shop in the local town, collected a new condensor and fitted. It didnt work, I cycled back again and got another... same result.
after the third visit to the shop the owner gave me the card (remember them, a card with small bags stapled on to it) and told me to try them until I got one to work. cant remember how many but it was good to get the car working again and I didnt have to change it again.
Wassells have Lucas condensors, currently made in Japan so should be reliable
Any condenser will do, doesn't matter what vehicle they are meant for. They should all be 2 micro farads.
0.22 microfarads is the ideal size. You can buy small solid state ones that are not polarity specific and mount them anywhere - even at the coil. If you do get one of the small solid state or whatever they are called ones make sure it is rated at 600 volts or it won't last.
There are one or two online suppliers of these specifically for bikes. I'll try and look up a name.
Google Brightspark or easycap condensers and look at their site
Back in the '80s we fitted the condensor on a mate's Starfire on the battery tray. Took a while to work out that the tray was rubber mounted....
Hi guys. Thank you all for your input.All of you comments/recommendations have been noted, and confirms that this is all the work i have carried out . until now.
With the knowledge that carb/electrics have been refurbish/re checked i have now checked the clutch, which was slipping whilst trying to start the bike.
Adjustments made and a good AMAL tickle, the bike is now easy to start 2nd/3RD kick.
So trying not to get to exited, thanks again.and fingers crossed.
bfn
Mike
Glad you got it sorted. It's rewarding isn't it when you solve a problem like that.
Checking, double checking and perseverance is the key.
HI MIKE > I HAD A SIMILAR PROBLEM WITH MY RECENT REBUILD OF TRIUMPH TR25W - SAME ENGINE FOUND PILOT JET HOLE WHICH IS MINISCULE ABSOLUTELY CHOCKED SOLID > THE ONLY THING THAT WOULD CLEAR IT WAS A VERY SMALL SEWING NEEDLE WHICH WOULD NOT BEND UNLIKE WIRE > AFTER THAT IT RUN FINE > DONT THINK SONIC CLEANING WOULD HAVE HELPED HERE , IT WAS LIKE GLUE . ACCESS TO JET IS BEHIND MIXTURE SCREW > REGARDS JOHNBOY
:) :) :)
Have you tried splashing some petrol into the carb before trying to start it from cold. If it makes a difference guess at fuel. If it doesn't you haven't lost anything. The only other thing that I can think of is an air leak, which will/could weaken the mixture.
Regarding condensers --check your spark if its yellowish==suspect condenser. Check your points--if there's any arcing==suspect condenser
Earthing throughout the system--bad earth weak spark which would possibly be more noticeable at cold.
Best of etc
Mike 8) 8) 8)
Hi guys.
I have decided to replace the clutch plates/springs to stop the slipping whilst starting the bike up. And because of the hard starting issue i believe the kick start spring is now tired or broken.
When i removed the clutch plates the kick start dropped and will not return. So i think the return spring has had better days. Any tips on fitment,? and reading some articles on bsa , they say drain gearbox oil prior before taking of the engine cover, but i thought on the b25 gearbox oil was further in the engine?
So when removing cover, do i expect to see oil draining out.
And secondly can i remove the cover without removing the points assy .
Sorry for these questions, but this area is new to me
Cheers/bfn/staysafe
Mike.