Having serious issues with the 253. Hasn't run right since I purchased the vehicle.

Coughing, throwing flames from the Carby and backfiring from the exhausts. No power but seems to rev hard occasionally between all of the above problems.

I�ve put a kit through the WW Stromberg and no improvement. Changed the Points, Condenser and Sparkplugs but again no improvement.

Checked the Leads, Dizzy Cap, Coil, Button and etc but all appear to be good.

Frustrated, I pulled the Manifold off to check the Cam Lobes and Lifters which appear satisfactory/good. Pulled of the Cylinder Head one side only) to check for a blown Head Gasket but the gasket was in very good condition.

I then proceeded to the Timing Cover and discovered that the Cam and Crank timing are 11 links apart (inclusive of the timing marks). However, I believe the links should be 9 links apart, is this correct? The chain is also using a chain tensioner which I have not seen other engines.

But the plot deepens further as the Timing Chain has two silver links, presumably to identify the timing marks, but are 11 links apart.

I�m totally confused. The Cam is not stock, the engine has flat top pistons 040 oversize, and big valve pre pollution HG Heads. I don�t have the specs on the Cam but going by the two silver links on the timing chain the engine appes to be timed correctly at 11 links apart but still havn't discovered the original problem.

Any help would be appreciated

Yes, I did the ignition timing with a timing light. But no improvement.

Manually time the engine...in other words ..get no#1 piston to the top and check for ignition spark at that no#1 cyl with ignition on slowly turn the dizzy till it sparks ..stop there and tighten it down,then check your firing order.let us know what you find..that engine is not in time.

Jim in Adelaide..

I think you're on the money with the cam timing.

Check out the pic below that I took of my timing chain before tearing down the motor.
Even though it's a VL Brock stroker, the cam timing is the same on the 253/304/308.

The dots are aligned with the bright links, which are 9 links apart (inclusive) or if you ignore the bright links, there are 7 dark links between them.



Cheers,

Mick
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Judge a successful man not on how he treats his peers, but on how he treats those less fortunate.

Perfect demontration Commodorenut...and thanks to all. I'm going ignore the markings on my chain and go with the 9 links as suggested.

Much appreciated.