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General => Douglas Motorcycle Discussion => Topic started by: cahallett on 20 Apr 2012 at 22:45

Title: Dragonfly spares
Post by: cahallett on 20 Apr 2012 at 22:45
Hello,
Can anybody advise if valve guides, pistons, piston rings and possibly a pair of cylinder heads for a douglas Dragonfly are still available?
My father in law has a Dragonfly which had not been started for several years.
The bike started nicely but is burning oil, however the compression feels good so we are thinking that maybe the valve guides are worn.
it would be nice to get the bike back up and running for the summer so if anybody can point me in the right direction for spares or has any advice regarding what the cause of the burning oil is it would be greatly appreciated (when the plugs are moved there is evidence of oil in the cylinder head (one side worse than the other).
Many thanks
Chris


 
Title: Re: Dragonfly spares
Post by: eddie on 21 Apr 2012 at 08:13
Hi Chris,
            Yes, spares are available from the spares scheme if you are a member of the London Douglas Motorcycle Club.
    If your father in law's bike is burning oil and has the original pistons fitted, I would remove the heads and barrels and check for stuck piston rings. The original pistons are of the split skirt type and are known to give problems if worked hard - the crown tends to collapse above the split, resulting in a wavy ring groove which then causes the rings to bind in the grooves. The usual remedy is to fit earlier Mark type pistons, or the repro pistons available through the spares scheme.
    Hopefully, this will be of some help.
   
      Regards,
                  Eddie.
Title: Re: Dragonfly spares
Post by: cahallett on 21 Apr 2012 at 19:38
Thank you Eddie,
My father in law has just joined the club so i have told what you have said.
I really hope the problem with the engine is a relatively quick fix, it is a beautiful motorcycle and i would love it to be back on the road as soon as possible.
Thank you again for your reply.
By the way how do you reset the trip on the main dial?
Best regards
Chris
Title: Re: Dragonfly spares
Post by: eddie on 21 Apr 2012 at 20:52
Chris,
         Originally, the speedo would have been fitted with a flexible cable for zeroing the trip mileage. The cable is just long enough to reach the bottom of the headlamp nacelle. Feel inside the bottom aperture, just in front of the forks, for the knob on the end of the cable - pull it down and turn it to reset the mileage. If you cant find the cable, take out the bolt immediately below the headlight unit - pull the bottom of the headlight forward to remove it. You will then be able to get to the bottom of the speedo head. If the cable has been lost, you will see there is a small shaft sticking out of the bottom of the speedo unit (about 1/8" dia with a cross hole) where the cable should fit. Try contacting Club Spares - they used to have the cables in stock.

     Regards,
                 Eddie.
Title: Re: Dragonfly spares
Post by: Les Mills on 25 Apr 2012 at 10:47
Hello Chris,
                      I can back up Eddie's advice re: piston rings, mine were just as he says.  It is worth joining the clubjust to get help from Eddie, and parts from the spares scheme.  Can't comment on anything else as my Dragonfly is not fully sorted yet.
                                  Regards,
                                                    Les
                                           
Title: Re: Dragonfly spares
Post by: cahallett on 27 Apr 2012 at 09:41
Hello Les & Eddie,
Well we have a theory about the burning oil.
We drained the fuel that we had put into the tank as there was a very slight leak and the colour of the fuel that came out was a reddish colour.
It looks like the previous owner after restoring the bike added a red oil based substance to the tank to prevent it from corroding (probably due to the fact that the bike was to join the numbers of his collection and remain unused).
Well the upshot of this is that this oil may be the cause of the smoking and once the tank is back on after washing out we will start her up and find out (fingers crossed).
by the way, how much oil should we expect to see aruond the rockers once the cover is removed? ours shows next to no oil but it has was only started once and very briefly due top the smoke scree it emitted.
thanks
Chris
Title: Re: Dragonfly spares
Post by: eddie on 27 Apr 2012 at 11:46
Chris,
        Only the previous owner will know what the additive in the fuel was, but as it was red, I would hazard a guess at Redex upper cylinder lubricant - this would give some protection to the tank without causing any other problems when it subsequently gets drawn into the engine.
     Regarding the rocker gear - this relies totally on mist lubrication once the engine is running. If the bike has been laid up for any length of time, I would suggest that it would be a good idea to go round the valve gear with an oil can about 12 hours before trying to run it. If the valves/guides or rocker spindles have dried up, it is a waste of time pointing the oil can at them immediately prior to running, as the oil wont have chance to penetrate. Bearing in mind that there is no positive oiling, I make sure everything is well lubricated on assembly. As to the amount of oil you would expect to find in the rocker boxes - about 1 teaspoonful as you remove the cover, and the internals just 'wetted' with oil. If you have removed the rocker blocks in the process of taking the heads off - replace the spring washers on the head studs with another plain washer, and seat the rocker blocks on a smear of 'instant gasket'. This will prevent oil from getting under the blocks and eventually finding it's way down the head studs and quite effectively waterproofing your boots!
          Regards,
                    Eddie.
Title: Re: Dragonfly spares
Post by: cahallett on 27 Apr 2012 at 20:09
Thank you Eddie,
We will follow your advice.
Kind regards
Chris