Mark Maras

That degree of improvement is very impressive. What insulation did you use? I'd like to see a few pics of the finished shield.

1. Any spot between the carbs and the and the filter. (if there is one between the pump and carbs) should be fine. 2. 4.3 is probably at the upper pressure limits of the needle and seat (fuel valve) in the float bowl. 3 - 3.5 would be better IMO. (Back in the day, we only ran 3 lbs. of pressure in a small block Chevy dragster.) 3. If the excess pressure isn't over powering the needle and seat valve, you're probably OK for now. The excessive pressure shouldn't affect the float level setting but it could cause premature failure of the needle and seat. A potentially disastrous scenario. Remember, the carbs are placed over the hot exhaust manifold.

Keep it. Think of it as a 401Z retirement plan. Where else can you double your money in a year of two? Clean 280's prices are on the way up.

Improved performance by adding choke indicates a lean mixture at the RPM that the engine was turning AT THAT TIME. I'd check fuel pressure and volume first, just to eliminate that as a possibility. Then I'd look at the carbs. Have you been using tech. info for Hitachi SU's or British SU's? HS6's were used on TR6's, among others. They had a similar engine size so I'm assuming they would be suitable for a Z. Re-check the float level. Fifteen flats down sounds about right for Hitachi's but I don't know the spec for British SU's. The new jets and needles could also be causing the lean condition if they have a different configuration than original. A comparison of the old needles and jets and the new ones may be a good idea. Did you have any trouble tuning and balancing them previously? Any of you electrical Guru's want to comment on the tach operating differently under load? That's a new one for me.

It's been theorized that wrapping the factory fuel line will aggravate the problem by trapping heat in the metal lines that may be coming from the mounting points on the engine. My own experience with SU's at higher elevation was a slight miss until I leaned them out 1/2 turn. Let us know what you find.

With the engine up to temp, while you're accelerating in third or fourth gear, gradually pull the choke on. If it pulls better with a little choke, the mixture is lean. It's an easy way to check for a lean mixture under load. How many turns down are the nozzle mixture screws?

Sad news. Jai's (RedBird) beloved friend Deanna passed on today after a brave fight with kidney failure. She was a dear family member and loved to "go for a ride" in RedBird. The looks from other motorists when they saw her must have been priceless. Mark

Oh, I recognized it as Puget Sound Patina. I grew up? in Enumclaw.

I thought that deep rich red patina was from salt water. You just can't get that special texture and variegated maroon color from rain.

IMO, Ignore the marks and rotate it until the tang is correct.

Be sure to give us an update. Hoping for success.

The various hydro carbons that make up gasoline have boiling points from 100` f - 400` f. The formula for gas is not precise and the quantity of components can vary from refinery to refinery. If the problem is new to a known working engine, Cliff may be right. The question now is how to cure it. A tankful of gas from a different station might be an easy fix or eliminate gas as the problem.

What are the chances of getting an autographed copy of the revised edition?

IMO, to eliminate the obvious, (no offense to the Cap'n) a complete tuneup is the first thing to do. It should be done sooner rather than later. I had one of those high RPM misses years ago. I convinced myself that it had to be something beyond the obvious (apologies again) and after much head scratching and many w.t.f. moments, it was finally cured with new plugs.

I'm visualizing this part, based upon the description, as a cover to protect the rear of the headlight bucket (and mounting screws) from all the crap that flies up onto it from the tires. Being familiar with the early 70 thru early 74's, I've never seen that part. However. Every time I had to remove a headlight bucket, I wished the car had a one. Did the 280's have a part like that?

Amelia Earhart? Danica Patrick?

Yeah sure. I remember when they introduced the idea of paying for TV channels. They said no commercials back then too.

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!

I always felt the same. Although I've never flown in either one, a P51 Mustang or a Supermarine Spitfire are the two that come to mind.

Are there any deep vertical scratches in No. 1, or did you get lucky?

If the pistons are rising equally, I think the butterflys must be opening. It would seem (IMO) that the problem is in either in the linkage, (doubtful) or it's just a basic "out of sync problem". Have you tried going through the synchronization procedure again?

I'm assuming that when you block the carb with your hand, you're feeling a lot of suction. Fuel level appears to be normal in the bowl. Is it possible that the nozzle is staying down in the full choke position even though the choke knob is pushed into the off position? Occasionally, the flat linkage piece that connects the cable to the nozzle needs a bit of a twist to function properly. Try pushing the nozzles up from the bottom with the choke knob off and see if either one will "click" into place. A bit of lithium grease on the sides of the nozzles is a good idea too. Kinda grasping at straws but I've not experienced a carb that does nothing when the piston is lifted.