Mark Maras

The original Z's only had a mechanical pump. Nissan added the elec. pump (among other things) to try to cure the heat soak problem. I can't say for sure if it will help but it can't hurt.

No complaints from Oregon, we are the Beaver state.

This sounds like lack of fuel to me. I had a similar problem years ago when my Z wouldn't go over 45 MPH, in any gear. Engine revved freely to redline, in neutral. I limped it to my Dad's house. After explaining the symptoms, he explained that regardless of what gear you're in, it takes virtually the same amount of gas to go a specified speed. We went out, opened the hood, blew out the filter on the fire wall, started it up and the problem was gone. I drove it for a couple of days before replacing the filter. No problems. Easy thing to check before you get into things too deep. If the filter check doesn't solve the problem I'd check the other filters, and fuel pressure and volume flow.

Gorgeous carb set-up. And complete too. No Google necessary. The reference to Jalex's Z in Panama was because his Z is backfiring on deceleration. It's talking back at him more than he likes..

Well, Duh. I forgot which bumper we were talking about. Suddenly, I feel like Emily Littela. Never mind!

Since I've never bought a Z bumper, I don't have a recommendation. I believe there are a few different styles in the early Z bumpers using different length rubber strips with holes in different locations. You may need new rubber strips with a new bumper. Those can get expensive. Hopefully others who have bought aftermarket bumpers will chime in. Maybe I don't understand the chrome shop's process. I'm picturing cutting the bumper, plating the three pieces in their small tank then welding it back together. I understand the welds are covered by the bumperettes (guards) but what coating is on the welds? Am I missing something about the process? Have you seen any examples of their work?

Cutting the bumper is NOT an option IMO. Is there a chrome shop in Colombia or Costa Rica that has a larger tank?

Oh, I think it's talking, It just takes some time for owners to learn the language.

With the possible exception of Jalex's Z in Panama.

That would be a dream come true. Thought I could put a trip together for Austin but it didn't work out. Atlanta is farther but even more tempting.

I don't remember them on my early 71. but who knows, maybe the P.O. considered them extraneous B.S. Never had a problem with brake squeal.

Two down, and five to go.

Great pics Jim. Thanks for sharing. BTW, love your wheels.

Perfect explanation, as usual. Thanks for adding the other possible causes.

I can understand opening the float bowls if they thought the floats were stuck. Can't imagine why they would have adjusted them. Oh well, it's better now. Keep us posted on how it's running.

From the beginning his plugs were sooty, Ignition didn't seem to be the problem so mixture had to be the culprit. The popping started with the new exhaust. Something about the old smaller exhaust prevented the popping even with a rich mixture. How many turns down did you end up with yours and how accurate do you think the float levels are?

Yeah, we discussed the cleaned? plugs before. I agree it's gonna be difficult to get an accurate reading with those. On the plus side, the car is running much better now. Probably due to the floats now being set more accurately than they were. @jalexquijano Did someone try to readjust the floats after they came back from Ztherapy?

Keep in mind that bowl gaskets can be glued to the lids to prevent them from Pringling, per Cliff's suggestion. I understand your reluctance to open them up again but it usually takes me several tries to get them perfect. Probably just me. Anyway, CONGRATULATIONS, IT'S RUNNING GOOD. I'd drive it normally for a week or so and check the plugs again. Keep in mind that the Hitachi's are designed to run at 2 1/2 turns down + or - with the fuel level 1/16" below the top of the nozzle for best results. Keep us posted.

Sounds like we're on the right track. My gut feeling judging by your float setting pics, the number of turns down and the color of the plug is the float level is a bit too low. Are you going to double check the float level with the sight tubes you have? Remember, with the chambers and pistons removed and the nozzles 2 1/2 turns down the fuel should be 1/16" below the top of the nozzles. That is what your goal should be when setting the floats.

I'm surprised we've heard nothing from @Redwing about Atlanta yet.

That works too. I've always preferred using up and down to describe the direction of travel. Left is loose (rich) and right is tight (lean) would work too.

I Agree. The 260's were-are the red headed stepchild for various reasons but being single year model they will be a rare commodity in a few years. They really aren't much different than the late 73 240's. Most people wouldn't know the difference if a 260 had 240 emblems.

Thanks for bringing that up Cliff. There has been a bit of a perspective problem in the past when it comes to adjusting mixture screws. Some, when looking down on the carbs, picture the mixture screws from that perspective, which reverses the direction in ones mind. Just for the record, clockwise brings the nozzle up and leans the mixture. Anti clockwise lowers the nozzle and richens the mixture. Should anyone still be confused, pull the piston and needle out and watch the nozzle as it is adjusted.

They look a little lean to me. How is the engine running? Have you installed the sight tubes on the float chambers to check the float level? In old post by @Bruce Palmer(Ztherapy), he says "Pull the chamber and piston. Look down at the top of the nozzle. The fuel level should be about 1/16" below the top of the nozzle for proper operation. Congratulations! It looks like progress to me.

Middle names are only worth 1/2 point.