Racing engine

[DavidZ1R]

Now then, on my little z550 project, when the engine runs, and I give it a little rev, the engine speed takes a while to settle back down to idle speed, the balance of the carbs are spot on, thanks to Geoff's (Z1Parr) kind loan of his vacuum gauges, I have checked for leakage of air, all seems ok, I hope that the carb float levels are ok, spent all last weekend doing them at a bit of a loss, any help

Also just noted that the petrol in the temp tank, which is open to the air, clouds up after a short while and 'blobs' of gel appear?

[PAULJAC47]

Hanging up is usually air past rubbers,spray wd40 around carb rubbers and see if improves temporarily,sometimes you think they are a good seal but if they are old and hard they normally leak specially if carbs have been off,,

[oldzed]

no chance that the cam timing is out 1 tooth?

have seen that on a z1000 before

[DavidZ1R]

no chance that the cam timing is out 1 tooth?

have seen that on a z1000 before

I hope not, the link count was perfect when I put it together, also the carb rubbers are new, could not be through the manifold rubbers? they are original, now the engine is an american one, with the emmisions thingy, which I have removed, but never blanked off the head port holes, was advised I did not need to, there are two vent pipes from the carbs, same size as the overflow pipes, could I be missing something I have not done.

[oldzed]

Have a look at this link

http://home.comcast.net/~loudgpz/GPZweb ... 00400.html

If Everything else is sealed then double check the valve timing. Should not take long and will rule it out.

regards

Craig

[Big Fluff]

Check also the mechanical advance unit, in particular the little weights that fly out.
The problem is that over the years the springs lose their tension due to the heat of the engine and the timing is then a bit too advanced at low revs.
This was exactly what happened on my Z500, but do bear in mind that you must fit the genuine springs to it and don't be tempted to fit springs that will simply fit and look right.!

[oldtimer]

there are two vent pipes from the carbs, same size as the overflow pipes, could I be missing something I have not done.

Are these vacuum pipes, can you feel them sucking, is the fuel tap vacuum operated?