Cam timing out.

[Superflash]

Hey y'all,

So got the Thunderbolt finished and have been trying to get the thing running.
Had new premier off 3 times now for cleaning and setting the float level. So happy with that.
Have fitted a Trispark EI with decent Trispark coils. Statically set with big fat spark. So all good there I think. Reset valve clearances to 8 thou inlet and 10 thou exhaust.
While I had the rocker cover off I brought each pot up to TDC on compression stroke and noticed that while the exhaust rockers had a bit movement, the inlet rockers were still under tension.
I'm now wondering if I messed up the cam timing?
Oh, did a compression test and only got a pathetic 80psi on both pots.
So the big question is...
How far do I have to strip the motor down to reset the cam timing?
TIA
Cheers

[V500]

If you'd messed up the cam timing the ex rockers would be out, too.
Rock the crank at TDC on the ex stroke; this quick and dirty test should show IN starting to open and EX starting to shut.
Personally I'd add some oil to the cylinders to up the compression and try starting again.

[rhyatt]

It's very difficult to get a decent pressure reading at kicking speeds.
Of course, you must have the throttle wide open (otherwise , there's nothing to compress).

A car engine at cranking speeds should be around 150/165psi ish.

So as above , drop of oil in plug holes and kick away, see what you get .
If more psi then the rings/rebore hasn't bedded in yet

If the same at 100 psi , I wouldn't worry yet about leakage past the valves yet too much.
If you get it running, it will bed in

[Superflash]

It does want to run. If I give it a really good tickle it'll fire and run for a second or 3 then dies. More kicking and big tickle and same thing. Just doesn't seem to want to catch and respond to the throttle. It has a new Mk1 premier and like I say, had it apart 3 times now to clean and set. Needle clip on bottom slot, float parallel with top lip of float bowl. Timing is spot on with the Trispark ignition. Only dodgy thing is lack of compression. But as you say, new rings won't be bedded in yet. Getting well frustrated.
Cheers

[rhyatt]

With the clip on the lowest groove , it'll be really rich.
Try the centre groove to start with and the pilot screw right in and back out 1.5 turns.

Good starting point (excuse the pun)

Sounds like the ingredients are all there.
Does your carb have a choke slide , both my bikes demand full choke this weather as well as some tickling

If no choke, Can you get it running with a good tickle and then keep intermittently tickling to tease it into life until it'll stay running on its own.
You may not have the new carb set at a tickover speed yet , so see what sort of gap you have under the engine side of the throttle slide , just a few thousand will do for starting, then you can adjust it better once running and warm

[limeyrob]

Could also be idle circuit, try 2 1/2 turns out to begin with if there's no better instructions.

[Gup holland]

A compression test with a cold  engine or a hot engine you Will see the psi raised.

Don't worry to Much.....

[nablats]

Just a thought - mine was similar, and the tiny passageways (pilot outlet & pilot bypass) which exit either side of the throttle valve were blocked. Below is an extract from a Vintage magazine article--

There are two small idle circuit transfer ports adjacent to the back edge of the slide. The smaller,Primary, transfer hole is 0.027″ while the Secondary is 0.040″.
• It is the Primary transfer port (smaller) that supports idle and transition between idle and main carburetors.
The Secondary (larger) has two functions. At idle it feeds additional air into the mixing chamber. The change in vacuum as slide just lifts from idle reverses the flow through the Secondary port. It now, instead of passing air into the mixing chamber, draws additional fuel into the venturi. This additional fuel helps to make the transfer from the idle carburetor to the main carburetor smoother. It is equivelent of the accelerator pump.

[Superflash]

I believe I may have solved the problem. Had the carb off again. Set needle clip to the centre groove. Blew every passage out with 100psi of compressed air. Made sure every one of them whistled with clear air ways. Put a new battery that I had in. Went toy it and same thing. Bugger....
Last thing to check, petrol flow. Well, left tap barely a trickle and right tap nuthin. Not a drip. So that explains the symptoms I had.
Will drain the tank and check the taps and replace if needed. What a drama..

[V500]

Without stating the bleedin obvious, did you not notice that tickling didn't show fuel on the carb?

[limeyrob]

Taken the fuel cap off and blow back up the fuel lines. If you possibly can leave the taps alone. There's a surprisingly large number of ways taking a fuel tap off can go wrong up to and including ending up with the tap and a section of the tank coming off together.

[Superflash]

Hi, yeh it did flood when tickled. But I suspect that would have emptied the bowl which couldn't refill quick enough. Taps came out easily and had a bit of gunk on them. Cleaned the filters and refitted. Getting plenty of flow now. Still wouldn't start tho. Fired, turned over a few times. Died. Oh, and there's fuel pouring out of the tickler. So carb off again to reset float. Starting to vex me....

[V500]

Tickling doesn't empty what's in the float bowl, it over-fills it with fuel from the tank.
Don't "reset" the float...look for any reason why the float needle isn't seating properly, like gunge on the seating or needle misplaced first.

[limeyrob]

If the tank is full of gunge it may now be in the little top hat filter inside the float banjo or jamming the float needle.  Its not unknown to have to clear the whole lot out several times.

[cdsdorset]

How are you checking the fuel level/float height.