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  #1  
Old February 2nd, 2016, 09:51 PM
RBBailey
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2.25 Issues

OK, so I have been driving the Series daily for four weeks now. So far, it is doing well. I think the knocking I heard/still do hear a bit of was actually just some advanced timing giving me a ping! Whatever it was, I retarded the dizzy a fraction of a turn and I noticed that the ping went away except for when at about +/-55 mph on flat. That is, top cruise speed. Then I do hear it, but it is less distinct, and doesn't seem alarming.

I also noticed that the truck just isn't as spunky as it was when it was running with some advanced timing. But it does reach 55 mph fairly smoothly, where with advanced timing, it would quickly go to 45, but really did not like going above 50. I suppose this is normal, but kind of a bummer to realize how quick the little thing "could be".

Now that I have this figured out, I want to make sure my carb is properly adjusted. The engine runs smoothly, I have noticed that it chuffs and coughs at high rpm when I ask it to give me more. It sometimes gently backfires between gears when not fully warmed up.

So the real question is, how do I properly adjust the Rochester carb in order to further narrow down the issues and see if I can really tune it right?

Right now, I have the idle screw (all it does is give a bit of pressure to the gas pedal linkage on the side of the carb, so the idle speed increases) set a bit high just to keep the idle from becoming rough while at stop lights. The idle speed might be just a tiny bit high, but mainly I just want to make sure the mixture is set properly.
  1. No choke
  2. Back idle screw off till just barely running.
  3. Adjust mixture screw till it smooths out.
  4. Adjust idle screw till about 800 rpm.
OK? No? What then?



Thanks.
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  #2  
Old February 2nd, 2016, 10:15 PM
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make sure the advance weights and plates inside the distributor are free to rotate and move around. Also, check your point gap. And you may also want to make sure the carb jets and passages are clean and clear and that the float level and needle valve are all set correctly and working properly
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  #3  
Old February 2nd, 2016, 10:42 PM
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Originally Posted by RBBailey View Post
OK, so I have been driving the Series daily for four weeks now. So far, it is doing well. I think the knocking I heard/still do hear a bit of was actually just some advanced timing giving me a ping! Whatever it was, I retarded the dizzy a fraction of a turn and I noticed that the ping went away except for when at about +/-55 mph on flat. That is, top cruise speed. Then I do hear it, but it is less distinct, and doesn't seem alarming.

I also noticed that the truck just isn't as spunky as it was when it was running with some advanced timing. But it does reach 55 mph fairly smoothly, where with advanced timing, it would quickly go to 45, but really did not like going above 50. I suppose this is normal, but kind of a bummer to realize how quick the little thing "could be".

Now that I have this figured out, I want to make sure my carb is properly adjusted. The engine runs smoothly, I have noticed that it chuffs and coughs at high rpm when I ask it to give me more. It sometimes gently backfires between gears when not fully warmed up.

So the real question is, how do I properly adjust the Rochester carb in order to further narrow down the issues and see if I can really tune it right?

Right now, I have the idle screw (all it does is give a bit of pressure to the gas pedal linkage on the side of the carb, so the idle speed increases) set a bit high just to keep the idle from becoming rough while at stop lights. The idle speed might be just a tiny bit high, but mainly I just want to make sure the mixture is set properly.
  1. No choke
  2. Back idle screw off till just barely running.
  3. Adjust mixture screw till it smooths out.
  4. Adjust idle screw till about 800 rpm.
OK? No? What then?



Thanks.
So you are running a lethargic 2.25 petrol with a Ford carb not designed for your engine, but for a larger displacement straight six and a distributor advance that after being adjusted is still suffering from Detonation and Pre-Ignition.

While there are always 2.25 exceptions, this engine struggles to reach speeds above 50 MPH, something it was never designed to do.
As a result Series owners often try low investment "fixes" in an attempt to gain more speed and performance.
As mentioned earlier, you are running a carburetor that is not included in any Rover Parts list because it is designed for a different engine.
Unless the carb has been re-jetted you are burning too rich.
Not having a choke is a good indication because a choke restricts air and with too rich a mixture, you don't need choke.
Advancing the timing will provide some increase in lower end performance and is often done by those who want more power, but have never experienced and don't understand the long term destructive results.
Have a friend with an 88" with the timing too advanced on his petrol 2.25.
Years ago, I explained that the timing was too advanced, the owner said it ran great and had more power...
It was pinging.
The same friend called me a few weeks ago looking for a new engine.
Before he explained, I asked "was it piston failure ?"... and he said how did you know?
Any ping is a bad ping as the detonation caused by pre-ignition will wreck your engine.

Your questions are not uncommon.
If it were my 2.25, I would loose the Rochester and install the correct Zenith or a "look alike replacement" or the single barrel weber designed as a zenith replacement.
I would also time the engine properly before you destroy it, see the workshop manual.

How do I reach highway speeds, you might ask?
The answer is you may or may not, but it is unlikely you will cruse at 65 - 70 with a stock 2.25 engine and stay up with modern highway traffic.

Enjoy it for what it is or look into engine replacements/upgrades which are generally a substantial investment.

Good luck.
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  #4  
Old February 2nd, 2016, 10:53 PM
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Check that the centrifigul advance is not broken. 2 minutes to pull the points off and have a look. Then check advance versus engine speed is you have a timing light and tach. Specs in the manual.

Check the vacuum advance and make sure there are no vacuum leaks.
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  #5  
Old February 2nd, 2016, 11:29 PM
RBBailey
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Quote:
Originally Posted by rdavisinva View Post
So you are running a lethargic 2.25 petrol with a Ford carb not designed for your engine, but for a larger displacement straight six and a distributor advance that after being adjusted is still suffering from Detonation and Pre-Ignition.

While there are always 2.25 exceptions, this engine struggles to reach speeds above 50 MPH, something it was never designed to do.
As a result Series owners often try low investment "fixes" in an attempt to gain more speed and performance.
As mentioned earlier, you are running a carburetor that is not included in any Rover Parts list because it is designed for a different engine.
Unless the carb has been re-jetted you are burning too rich.
Not having a choke is a good indication because a choke restricts air and with too rich a mixture, you don't need choke.
Advancing the timing will provide some increase in lower end performance and is often done by those who want more power, but have never experienced and don't understand the long term destructive results.
Have a friend with an 88" with the timing too advanced on his petrol 2.25.
Years ago, I explained that the timing was too advanced, the owner said it ran great and had more power...
It was pinging.
The same friend called me a few weeks ago looking for a new engine.
Before he explained, I asked "was it piston failure ?"... and he said how did you know?
Any ping is a bad ping as the detonation caused by pre-ignition will wreck your engine.

Your questions are not uncommon.
If it were my 2.25, I would loose the Rochester and install the correct Zenith or a "look alike replacement" or the single barrel weber designed as a zenith replacement.
I would also time the engine properly before you destroy it, see the workshop manual.

How do I reach highway speeds, you might ask?
The answer is you may or may not, but it is unlikely you will cruse at 65 - 70 with a stock 2.25 engine and stay up with modern highway traffic.

Enjoy it for what it is or look into engine replacements/upgrades which are generally a substantial investment.

Good luck.
I was lead to believe that the Rochester was a close second to the Zenith, and I wouldn't have expected that it would be a problem. Land Rover FAQ - Rochester conversion

I do have choke, and have to use it to start when cold/cool. Before I bumped the idle adjust up a bit, I had to use a bit of choke to bring the idle up at stop lights.

I don't want to go above 55. Used to have an overdrive, that was fine then, not now. I was just using that as an example of what happens when I get to 55. It seem to be fine going there, just not above. That's fine.

I had realized the timing was too advanced, I was explaining how I had pulled it back, and the ping has gone away.

I don't want a different engine on this. I would want an overdrive, but I'm saving that for the 110.



I've attempted timing from the Green Bible and the workshop manual a few times. I need a visual guide/video to show me what the heck. For some reason it's one of those mysterious magic unicorn things to me.... I mean, I get why, and what it is, but the instructions I've seen just don't make sense when I actually get started on the project.
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  #6  
Old February 2nd, 2016, 11:36 PM
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If you can't figure out setting timing you need someone to come and help you. You really need to go through the ignition system completely. Sounds like a broken advance spring but who knows.

You should pull up to 60 comfortably.

If I were to set up a carb properly in 2016, I would beg or borrow a wide band o2 sensor for a day.
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Old February 2nd, 2016, 11:51 PM
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Something I've always wondered about is how there is play in the cap of the distributor. That is, the two clips that snap over the slots on the cap, even if they are holding it tight, you aren't ever going to get that cap back on the distributor in the exact position it was before. How is it that the timing at the distributor isn't messed up by simply pulling the cap off? In my mind, the arm is going come across those contacts at a different spot if you open the cap.

...or is that just a stupid question?
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  #8  
Old February 3rd, 2016, 12:02 AM
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The cap should be held down tightly. If it is not, then bend the clips so they hold it tighter.

There are notches in the cap to prevent it tuning and locating it precisely.
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Old February 3rd, 2016, 12:05 AM
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Even if it is held tight, which mine is. The simple act of taking it off and putting it on would put those contacts 1/2 degree off one way or another, unless you have some way of putting it back on in the exact position where you pulled off from.

BTW, it is the Lucas etc5835, and not very many miles on it. Engine is 7:1.
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  #10  
Old February 3rd, 2016, 12:08 AM
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There are notches in the cap that locate it in the same place. It can't move because of the notches.
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Old February 3rd, 2016, 12:11 AM
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OK, just making sure, because the tiniest movements on the body do affect the idle.

The pinging that I was getting under any load did go away. However, since I think I'm still detecting a bit at higher RPM's should I maybe retard the dizzy a 1/2 degree more, then adjust idle to fit?

This is assuming that the static timing was actually set properly at 6 BTDC.
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  #12  
Old February 3rd, 2016, 12:14 AM
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A few degrees here or there should not matter. Do you have a timing light?
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Old February 3rd, 2016, 12:15 AM
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Something else is wrong. Pull the points plate off and take a picture of the advance system.
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Old February 3rd, 2016, 12:51 AM
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A few degrees here or there should not matter. Do you have a timing light?
I just backed it off about 1/2 degree. Just enough to barely hear the difference, just enough to see that the mark I made with the sharpie rotated. If I go forward a degree, I will get pinging under any load while driving. The sweet spot is very narrow...

It ran fine, but would not go above 45 mph without coughing and sputtering with more gas. And I failed the hill climb to my house twice. I eventually made it after a good run at it, and shifting all the way down to 1st for a 1/4 of a mile...

In other words, I need to advance it back to what I know is the sweet spot now.

I will look inside the dizzy and get a pic for you now.

Thanks for the help.
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Old February 3rd, 2016, 01:22 AM
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Pics.

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Old February 3rd, 2016, 01:23 AM
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Cap.

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The contacts here are white ...?
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Old February 3rd, 2016, 01:43 AM
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Cap. The contacts here are white ...?
Corroded?
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Old February 3rd, 2016, 02:03 AM
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If it is, it was just a small amount.

Figuring a clean contact is best, I cleaned those contacts with a few swipes of 220 sand paper, and I did the same with the rotor arm.

This might have fixed a bit of an issue I was having with a coughing sort of half-beat hesitation when at idle, then hitting the gas quickly, as when starting in 1st on a steep hill. At least, seemed to run a bit smoother, and didn't give me that hesitation when I started it.

A drive will have to wait till morning though.
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Old February 3rd, 2016, 02:05 AM
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By the way, this is what happened when it would not start for a hour yesterday after work. Always good to have like-minded, empathetic people around.

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  #20  
Old February 3rd, 2016, 07:38 AM
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I ran a Rochester Model B carb on my Series for 30+ years and loved it. It is a dead simple carb. I found that a .49 main jet made the carb "fit" the engine. I adjusted mine by setting the idle up a bit from normal with the engine warm, no choke and vacuum advance plugged, turn the mixture screw in until the idle speed starts to drop, and then back the mixture screw out one full turn, set idle speed back to normal. I would then watch the color of the spark plugs over the next few runs to decide if it needs the mixture adjusted a little one way or another. Are you setting timing with the engine running with a timing light or does your Series just have the timing marks on the flywheel? Check your vacuum advance to make sure the diaphragm is good. With the distributor cap off, apply vacuum to the vacuum line and you should see the base plate move if it is good.
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