Mark Maras

No relay clicks in my early 260, but that may not be of much use. Mine, at this time, is running but I have virtually no power to the dashboard yet. May be a clue there.

To really understand these carbs, ZTherapy,com has a DVD that has all the info that you will need. I considered myself pretty good with SUs, having run them for decades with little to no trouble but I was surprised at the tips & tricks that I picked up from the video. I don't understand why you changed the needle height to lean the mixture, Needles should be the same height on both carbs Shoulder of the needle even with the bottom of the piston not even with the groove. The mixture adj. is done with the the nozzle nuts after ensuring the float levels are at the right height.

Why the difference in the previous 4500 rpm & the later 3500 rpm. Was the difference caused by creeping the rpms up on the 4500 & stabbing the throttle on the 3500? Also, did pulling on the choke make any difference? Mechanical pumps alone will supply plenty of fuel for round top carbs on a L26 if the filters are maintained.

Sounds like fuel starvation to me. Not ruling out ignition but a plugged filter will restrict RPMs under load. A quick check to see if it's lack of fuel, rev the engine, in neutral, to 6000 RPMs, If it happily revs with no load, it's lack of fuel, Another interesting symptom is the car will go the same MPH in any gear & no higher, When it happened to me, all of a sudden the car would not go over 45 MPH. Second, third or fourth gear, 45 MPH. No engine miss, the engine ran fine, My dad was my riding mech. that day & immediately knew what it was, I was able to blow out the filter by the fire wall as a roadside fix, Start with all the fuel filters. Possibly one in front of the tank, another at the fire wall & one on each carb. Fuel pump pressure & volume is next. Hope this helps.

Wow, That's impressive if nothing else, That noise just topped my list of strange noises from machines. I'm with Blue, Tires on painted concrete was my first thought. Second was a puppy under the tire, I'd go to my 3' garden hose stethescope. With the help of a friend moving the s-wheel( I'm assuming that is what you're doing when the noise appears), you should be able to poke 1 end of the hose toward the noise from above or below, the other end to an ear & locate the sound. An ear plug in the other ear may help muffle the noise. Please follow up & let me know what you discovered. I need closure. Mark

That may be a good price but they aren't the carbs you want. Almost everyone uses the round top carbs. Earlier vintage & very adjustable. Bruce at ZTherapy would be a great person to advise you. You don't want to end up with nice shiny carbs w-worn throttle shafts.

Engine off, work the carb linkage by hand, It should feel smooth thru the entire range. Idle then WOT then idle. Push the linkage towards idle is there further movement? If so look for the cause. Lube all pivot points, & try it again. During the fast idle try lifting the pedal to see if the idle drops. I highly recommend ZTherapy's Just SUs DVD. It's the Gospel on SUs. As far as the Uni-syn goes I adjust the U-S(the center of the U-S screws in & out) so the ball is close to centered first, then I check the carb balance. I think you'll need to recheck the carb tuning.The only reason that I can think of to clip the springs is if you wanted more pedal pressure.

Inspite of being sure the float level is right, 4 1/2 turns down would be neccesary if the fuel level was too low. You said the bowls were full. The level has to be near perfect. Just a thought that hadn't been brought up. Have you tried pulling on the choke to see if anything changes. It's a handy way to check the mixture especially if it's lean.

Several things to consider; RUST The #1 problem with Zs. Take an ice pick & poke any blisters(paint or rust)-Fender wells, body below the doors, frame rails, floor pan, spare tire well, seat supports, cowel in front of the windshield, pull the battery, this a notorious place for rust. VOE I scanned the project 260 that I bought last fall fairly well for rust, or so I thought, Things I missed; Seat support, Hole in the rear of the right fender well. Behind & below the battery. OK I can deal with it, then I open up the right frame rail from the inside.I haven't seen that much rust since I left the ship repair yards. My 6 month project no longer has a definitive on the road date. OK, Engine,a working starter & a battery will allow you to do a compression check. The dash looks good, could mean a car that has been under cover much of it's life. Enjoy the project.

Just another jab at Lucas "The prince of darkness".

No, it doesn't sound good. At this point turning the engine over may be a waste of time. However, you may break it loose by pushing the car in gear, & engaging the clutch while it's rolling. While a rebuild for this engine may be inevitable perhaps a short term fix would be a swap. There are more engines avail. out there than cars. I'm sure a lot of members have spare engines for sale. Almost all of us have had buyers remorse as we discovered the true state of our dream. Often the project grows beyond our time, talent & money. Determination & desire keep the dream alive. You're about to discover how much of both you have for this project. Keep the faith.

My first impression is lean mixture. Round tops or flat tops?

This gem from my daughter "The only people that understand women are other women, That's why they don't like each other."

What color are your plugs? This will tell you which carb needs adjusting. If the mixture screw adj. is substatially different between the two the float level is off. The best source of info on SUs is the SU DVD from ZTherapy.

I don't think leakage is supposed to be normal. I noticed the same spots under my hood about six months before my fan clutch seized. I replaced mine with a flex-fan, You may want to start lokking for a replacement now rather than later.

The problem is fuel related. but checking the valve clearance first is a must do. These carbs are very simple to work on so don't be intimidated. Remove the air filter & housing. While another person operates the choke reach under each carb & check for full movement of the nozzles. With the choke on, grease the nozzles. Check the oil level in both carbs. With the carb intakes exposed, lift the pistons all the way up & let them drop. They should drop at about the same speed & should feel smooth. Pull the float bowl covers & verify that there is fuel in the bowl & it is about 19mm from the bowl rim.(warning, the gaskets will Pringle on you so it's a good idea to get new ones first).Turn the mixture screws all the way up & note the turns. If the float level is close the m. screws will be about 2 1/2 turns down. Let us know.

They are either made of gold or they are being held for ransom. I'd guess the latter. The key to this is getting the description and heading to your local hdwe. store that has a good supply of bolts. Even if you end up using the trial & error method to find the right ones, it will not only cost you less than $10,00 but the best part is you will have learned the bolt section of the store. You'll be surprised at the amount of time spent chasing down fasteners. My rule of thumb when dealing with bolt strength is, soft bolts stretch before they break and hard bolts will snap with no warning. I usually go for grade 5 vs grade 8 for general use. I'm not up on the metric equivalant but a quick trip down Google Way will get you the info.

On my 71 the "clothespin" springs, at the base, are not hooked in the loop. They are hooked on the back side. I really don't know which is right. As far as I know the head has never been apart. Is that a collet or piece of one on the right rocker?

If you're going to use a Datsun engine Rebello(sp.) is the answer for a high H.P. Z engine although 400 hp may be optimistic. If your choice is non Datsun, HybridZ has a lot of info on other swaps. These cars like lightweight engines. I've thought seriously about a 13B too. If you need info on that swap, I know a fellow near Portland who has put rotaries in; Triumph Spitfire, Volkswagen Beetle, MGB & many more than I can remember. He also rebuilds rotaries for the Mazda dealers & Bonneville salt flats. PM me if you want to contact him. I think this would be an excellent choice.

Welcome. You've come to the right place. Your story reminds me of my mom & my 396 Chevelle. She asked to take it to the store, next thing I know she's back inside telling me to go get my car out of the street in front of our house. She got it out of the driveway but it scared her to death. So she parked it in the street. Then she's on my dad's case because he's the one that was supposed to force me to sell it. Long story short, he drove it & I still remember the GRIN on his face when he came back, & the hell he went through with her because he said I could keep the car. Thanks dad. You will recieve lots of help from this club. Great info & willing members.

I use auto-resetting circuit breakers when working on specific circuits on my cars. They replace the existing fuse & are avail. at NAPA.

If the cat won't go for it, you may want to try them with milk & sugar. it's a possiblity that the PO's kids dropped cereal down the defroster vents. I've found some interesting things that were lodged in the blower fan that had to have come from the vents.

A couple of questions; Are there any other symptoms, Shifting, high speed vibrations, noise in any other gear? What shaft did you have to press in? Describe the diff. float.

I've never heard of all the rings going at once except lack of oil. Pull the valve cover and turn the engine over with the starter & see if everything looks normal. Before you give up on this engine it's worth checking the valve lash one more time. The adjustment doesn't have to be very far off to raise hell with the compression. If you go with the 200K engine it would be a good idea to take a c-test on it too.

First check the fuel pressure. Pull the outlet line & crank the engine over. It should squirt a fuel a couple of inches, once for every engine revolution. Check the fuel filters in the banjo fittings on the f-bowl tops. Turn the mixture screws all the way up & count the turns. 2 1/2 is about normal. If these are considerably different it is an indication that the float level is wrong. A quick search of "Quick & dirty carb tuning" will get you the details you will need.The best info I've found is from ZCarTherapy. They have a DVD on just SU carbs that explains all you need to know.