Fuel levels Hitachi carbs

[Sam_C]

So…after getting advice that my problem posted on the electrics section is more likely a fuel issue…here I am on the (hopefully correct) area.
I took my float chamber lids off in order to check the float heights. First thing I noticed was when I removed the front flexi fuel pipe from the rail to the carb, it was empty, no fuel at all came out. I took the lid off , then took the float assembly out. The level of fuel was very low -I’ll try to post a pic. On to the rear carb - this time there was fuel in the flexi pipe, and the fuel level, although higher than the front still looked low. So first question - should there be fuel in both the flexi pipes at all times? I could maybe at a pinch imagine the rail not being full and if that was the case the slope on the engine hence the fuel rail would pool any fuel towards the rear flexi pipe. The fuel filter situated by the (mechanical) pump is full, so the fuel isn’t going back that way. Secondly - how much fuel should be in the float chambers when “at rest?”. The car has been standing for only four days. I’ve had a long-standing issue of when I come to start the car after it has been standing for some weeks, it turns over for an age before firing - just wondering now if the fuel is disappearing somewhere and it needs a longer time to refill the chambers before it has enough on there to start, especially as it needs choke . Ideas?

Edit : pics attached - the one on the right is the front carb.

 

[Farmer42]

I was waiting to see if anyone was going to reply first but it don't look like it. My previous measurement on float height was incorrect. It should be 14.5 mm from metal tang on the float to the underside of the lid. As far as I recall it should be the same on both carbs but it's a while since I ran Hitachi's so I may be wrong. I currently run British HS6s which are slightly different.

As far as fuel in the pipes, you may get a dribble but not much. Fuel pressure will ensure the remainder in the rail and hoses runs back through the return to the tank. If you are worried about fuel feed to the carbs, you can test it by cranking with the hoses inside a jar and you should see it squirt. Take the HT lead out the coil first. If no squirt on any hose, your rail may be blocked or your fuel pump may be faulty.

The float bowls should be just under half full as far as I remember but the correct float height setting will sort that.

 

[Robert]

Sam C. You should find the section on setting the floats of interest,

Datsun ZCARS L-Series Engine Rebuild Tips

Datsun 240Z and 280Z L28 engine rebuilding tips

datsunzgarage.us

 

[Sam_C]

Thanks Robert. The procedure simple enough, the problem is the number of different ways of measuring the height and therefore different figure to aim for! I looked at my Nissan FSM and it says “set dimensions H on Fig E-xx to..” Checked fig E-xx and there was no dimension H on the pic

 

[Robert]

When I first got my 240 it was difficult to start, jerky on part throttle and fouled it's plugs. I spent weeks on and off tweaking and balancing my carbs and now it's a totally different car. Pulls cleanly from low revs in the higher gears, starts far more easily, doesn't foul its plugs and ticks over smoothly. I used a synchroniser and as a novice found it indispensable.

I set my floats according to the Haynes manual page 57 (see attached)

I also found this video useful as a starting point.
https://www.google.com/search?q=240...#fpstate=ive&vld=cid:732d4813,vid:0Vadtt-ljfc

Good luck.