A65 Thunderbolt Rocket no start

[shaun evans]

Hello all,

For the past 7 months or so I've been restoring/rebuilding a 1964 Thunderbolt Rocket from what basically was a pile of rusted parts. I've got to the stage of firing her up for the first time but she will just not start. Not even a pop, spit or bang.

The bike has been converted to 12V and is fitted with a Pazon Sure-Fire ignition system running two new 6V coils in series.

The timing marks on the gears all lined up correctly when I re-assembled the engine and I'm getting healthy sparks at the plugs when they are out and touching the head.

The Pazon is set up correctly I'm sure. 9.1mm BTDC and the dot lines up nicely in the hole on the trigger plate. Even if the timing was a little out I would have thought there would be signs of life.

Both plugs/caps/leads have been changed, compression is good.

I can see the valves opening and closing through the plug hole.

The bike is fitted with a new Amal 389 Monobloc correctly jetted. It seems to "suck" ok when kicking over, but even after a good tickling the plugs remain dry and there are no signs of fuel on the piston tops.

I've even tried "easy start" directly in but not a peep.

I'm baffled now.  I must be missing the obvious but I can't for the life of me see what.

Your thoughts on this would be greatly appreciated!

Cheers.......................Shaun.

[A10 JWO]

Is it possible to set the timing 360 degrees out, just thinking of things I have heard back in the old days. Just wondering if it is sparking on exhaust cycle or do these have wasted spark. Sounds like timing to me ? Keep updating ?

[DerekAnderson8]

if the plugs are dry then that is where i would start, remove the plugs and try adding a few drips of petrol into each cylinder, replace the plugs and give it a kick.

If there is still no bang at all you should then look at ignition timing and possibly valve timing although with these both out you can still get a pop or a bang.

[shaun evans]

Hello and thanks for your reply's.

The Pazon ignition system is the "wasted spark" type so can time up on either cylinder?

I'v put both Petrol and easy start directly into the combustion chamber - nothing.

Sure the timing is okay, and as you say even if it's a bit out I should get something.

Cheers........Shaun.

[Mike Farmer]

 

Shot in the dark---very recently on here someone with virtually the same problem had a duff set of brand new plugs. Sparked OK in the open but not under compression.

Mike

[chaz]

having fitted many plugs for customers, Ive only ever had one plug supplied a failure. its possible, but two in the same batch...
when I had a Vauxhall Viva, first car, I cycled 5 miles each way 4 times in the same day just to get a condenser that worked. In the end the autoparts shop gave me the card of condensers and told me to bring them back when I found one that worked. They were the good old days!!!
valve timing will probably spark in manifold or exhaust..
Easy start normally works, my guess is like the WD B33 Im working on, same as the AJS Stormer I used to race, crankcase pressure. the AJ wouldnt run if fuel mix too rich and took up space under the crank so had to be drained, likewise Im getting a lot of friction (could be crank pressure) trying to kick the B33 . My A7 wont start if it has wet sumped........my best guess.

[shaun evans]

Hello and thanks for the replies,

On second set of new plugs now so hopefully not that.

Not sure I understand the crank pressure theory. Are you suggesting it might already have wet sumped or the mixture is too rich?

Cheers.........Shaun.

[chaz]

https://www.burtonpower.com/tuning-guides/tuning-guide-pages/engine-breather-system.html

I  remember there is a vent disc and spring on the A65 cam shaft, some people leave off others on.
have you checked compression

[ducati2242]

When I first started my DB500 I must have kicked it over 200 times checked compression checked timing . Valves and ignition . It wouldn't start , had new carb , piston , valves , crankshaft , camshafts , bearings  everything was right . Late at night I decided that this was the last kick of the day and bang straight into life . I didn't even have to adjust the carb it just ticked over . Now it starts first kick , touch wood , . If I had bothered to look at the internet and read the starting procedure for a gold star I would have saved myself a sore leg , and head , and  4 hours of checking . So could be nothing at all but process of starting . Have a look at the good old internet on the starting procedure .

[shaun evans]

Hello and thanks again......

Chaz, there is a breather disc/spring assembly on the end of the cam. Compression seems very good, although not tested with a gauge only the right boot.

Duc, this extract from Brit Bikes Forum seems to sum it up. "When we say that these Brit bikes have "character" very often it means that although ostensibly identical they can require different treatment to start and run properly".

I've had all sorts of classics over the years virtually all with Amal carbs and they've mostly needed a different technique to start them. My 64 A50 just needs a tickle, a prime kick and then she's off first or second go.

I've trawled the net. There are so many different ideas on how to start various types of bike.

It might be a good idea though to jot them all down and work through them one by one!

Cheers........Shaun.

[DerekAnderson8]

a second opinion is always a good idea, whereabouts in the country are you? i am sure somebody would be able to help if close enough.

[shaun evans]

Hello Derek, thanks for your reply,

A second opinion and a look see would be most welcome, the kettle's always on!

I'm in Rushden Northants,

Cheers.....Shaun.

[Mike Farmer]

 

Not Toooooooooooooooo far from Glasgow then !!!!!!!!!!!!!!!!!!1

Mike

[chaz]

drained the sump, loosened the 4 nuts and let out around a pint of oil in the M20/B33 today. let it drain while sorting out the feed to the carb....
carb has a reservoir (276) and wasnt filling more than bottom hole. disconnected and moved pipe then free flow. carb float is , I think clipped too low, filled reservoir, replaced dry plug after a couple of kicks over tdc have had the bike running a couple of times.
need tooo...
get new plug
see owner about carb, well worn and float clip soldered to float.
plug is rich and looks like piston is coated in carbon, reccomend a decoke.

as plug was one supplied, wouldnt start on easy start only other thing done was drain sump. its easier to kick over now as well.

[johnjag]

When I finished restoring my A10 Plunger it would not start. So me and two of my younger friends tried to push start it many times on the long bank outside my house. When we were all worn out we bumped it for the last time and it popped and banged and fired a bit but did not start! I rolled it in the garage and we all sat on the floor panting. 20 minutes later the lads were ready to go. Paul just walked over to the bike and kicked it. IT STARTED! It has started 1st time ever since and runs like a switch watch. So don't give up and try push starting.
John.