Starting a SW5

[zacgrief]

Gents,

Can anyone send me an idiots guide to starting the SW5. Never started a bike this old before never mind an SW5, I have a spark, I have fresh fuel in the float chambers. I seem to be getting the odd fire on the front cylinder but nothing on the rear (bump start by the way).

If someone could give me some rough control settings/ anything obvious to do/ not do, then if it still wont go I can look at the more technical stuff.

Many thanks

Zac

[eddie]

Zac,
       As this bike is something of an unknown quantity to you, it would pay to do a few basic checks.
       Firstly, has it been set up to run on petrol or methanol? If it is setup for petrol, the main jets will be about .050" dia bore. For methanol they will be more like .080"(or larger!).
      Secondly, do a rough check on the ignition timing - it should be around 38 degrees before TDC.
      With these checks done, apply a few drops of engine oil to the valve stems and rocker gear. Then prime the engine with one pumpfull of oil using the hand pump in the tank. Turn on the fuel and tickle the carbs until they flood. You should now be ready to bump start it. With the motor turning, bring up the throttle gently - too much throttle will cause it to fire and kick back - even with the ignition somewhat retarded!
      Obviously, bump starting can be somewhat worrying - especially with a machine you with which you are not familiar. If you are still having problems getting it started, why not bring it along to the Douglas Club rally - there will be members there who have enough experience to help you out. I, for one, will have my DT based sprinter, and a set of starting rollers (a lot easier than bump starting!).
     Looking forward to meeting you,
                           Regards,
                                    Eddie.

[zacgrief]

Eddie,

Thanks for that, mine also appears to have a choke/ mixture lever. I assume when the cable is pulled it is making the mixture richer. Also when the advance/retard lever is fully closed i dont get a spark, if i open it 0.5" it sparks, is this the way it works to stop the engine as it has no other magneto earth or is it a fault?

I will check the rest tonight and report back, thanks for the help.

Cheers

Zac

[eddie]

Zac,
       Assuming you have the usual AMAC carbs, the mixture should be richer with the cable slack. Also, the fact that you have no spark with the mag fully retarded, may mean the mag has been tampered with or is in need of a rewind.
      As I said before - bring it to the rally and we'll be able to diagnose the faults. I'll have my spares there, and, if necessary, we can change the mag to see if that is the problem.
             Regards,
                            Eddie.

[zacgrief]

Hi all, main jets are marked up 110 on left carb and unidentified mark on right carb. Drilling measures just under 1mm with my vernier which equates to just under 40", so thats in the right ball park to Eddies post or looks like its a petrol machine anyway. Spark definately deteriates when mag retarded so poss mag issues. Carbs keep flooding with petrol on and float needles look worn so i need to see if i can get new new ones or or re-seat and adjust old ones. Any ideas here how to get float/ petrol levels correct? i dont want assume they are correct heights now and machine to suit.

Looks like choke/ mixture works by opening lever and allowing air into the carbs via slots on carb bodies so yes mixture rich when cable is slack with lever closed.

Couple of pics attached.









Many thanks

Zac