Speaking of vibration

[Hubie]

Hi all,

Just reading up on setting the timing with the head off, supposed to be the best way to get your btdc mark exact as you can, and have noticed in the haynes manual that there are flat top pistons in place.  Mine are not and I can only assume must be high compression jobs.  Is anyone able to confirm this?

Also, i have a four spring clutch that has the pushrod and outer pressure plate as one item.  I have adjusted the spring screws so that the top of the thread is about level with the top of the screw heads and the clutch looks to be working well.  Does anyone have any tips on getting this type of clutch fettled just right?

Cheers,
Hubie

[muskrat]

G'day Hubie,
                the domed pistons will not make any difference to your BTDC measurement. Flat tops are about 7.25:1 yours may be 8, are there any #'s on them?
With the clutch make sure the pressure plate lifts square. That is, with the lever pulled in (use a cable tie to hold it) turn the motor over and use a dial or scribe and adjust the springs so it turns true.
Cheers

[Hubie]

Thanks mate,

All done up and the pistons appear to be 8.5:1

The head is now on so all i need to do is put the rocker box and carb, exhausts on and give it a kick

Cheers,
Dave.

[Hubie]

I finished putting her together last night.  It's so darn good to see her all in one piece again, hasn't been that since last october.  I didn't run the motor though as it was near 11.30pm here so I'll fire her up this morning.  Have been constantly kicking it over without fuel or spark to get some oil through the motor first.  I have checked, and re checked and re checked the timing and I am confident it will start fairly easily.

Fingers crossed boys!

[Hubie]

It's alive!!!  three kicks and it fired straight into life and it feels awesome!  After the smoke cleared, I have a nice plume of black smoke even with the pilot air screw all the way out so I think I need a much leaner pilot jet but other than that I think it's spot on!

Thanks to all who have provided advice and encouragement throughout this whole ordeal.  I will have her on the road very soon!

Cheers,
Dave.

[Brian]

Great news Dave, its good that it started easily, that usually means that all is well. Well done !

[Hubie]

Does anyone have a late model concentric mk1 on their flash?  Mine has no pilot jet, a 106 needle jet (with the two small holes in the side) an number 3 slide and a 240 main jet.  I've put it all back together and put the needle clip in the top notch to see if it will help with the richness and now I can't get it to fire up.  I did tickle the carb again but I don't think it's flooded.

Cheers,
Dave.

[Hubie]

Brand new plugs giving no spark.  Changed to some spares, bike revved right up, I had to shut the fuel off as the idle stop was way to high.  It now runs a treat with no smoke.  Very very smooth with lots of power and a clean idle.  Only thing I had to change was dropping the needle down one notch.

Cheers,
Hubie.

[muskrat]

Great to hear Hubie, recon she'll be a treat to ride now.
 

[MG]

 wink2 wink2 wink2

[terryk]

Good on you Dave glad its running it wont be long and you'll be flying down the highway. It will be worth the wait and effort. cheers Terry

[bsa-bill]

Well done - these plugs are getting to be an issue

[chaterlea25]

Hi Hubie,
Well done 
I think this must be the longest thread on the forum ????

The concentric carb does not always have a removable pilot jet ( thats a long story)
in behind the air screw theres a brass bush pressed in with a tiny (0.015 or so) hole in it
On a lot of bikes this pilot jet is too small, I have found it best to ream this  out to 0.020in (0.5mm)
with a jet drill. this will give better response from ow down
It is quite common for this jet to be gummed up if the carb has been lying idle for a period of time

I think the 240 main Jet will be too small for a 650?? the Haynes (liar) book says 270 for an A7 and 250 for A10 which  doesnt make sense  ???? ????
I have  a Mikuni on my SR so I cant check that for you!!

HTH
John O R

[bsa-bill]

240 is correct for a Flash John ( in a 389 monoblock)

[Hubie]

Thanks for all the kind words lads,

I did some snooping around and had a chat with a friend whose full time job is to restore bikes (british only) and he's told me that the 240 main jet will be fine in the carb.  It will be a little while before I get the throttle open far enough to check that jet while she's running in.  The plugs I bought were champion l82c plugs and only lasted for two runs around the block while I was fettling the carb.  The ones in it now are champion l86c's.

I might have to invest in some ngk plugs I think.  That crank you sold me is a cracker Terry and I also used the oil pump you supplied as well.  I kicked the bike over for quite a long time before putting the carb and plugs on as I didn't want the bike running for ages without oil going to the big end.  Last time it was over two minutes before I saw oil returning to the tank. This time it was about five seconds.

This is indeed a very long thread so I may start a new one for when she's registered and and being run in.  Some video will make its way to youtube soon.

Cheers,
Dave.