HELP! All Mechanical Eliminated- Wont rev past 4K

[ChrisZ]

You got a point there Stephen. maybe he should pull his trailer off of the tow hook:D

Chris

[Seanw987]

Some Progress Made.

I went to see the Z this past friday and I got some good news and some bad news. The good news is that the car is revving to 5400 RPM now. The bad news, minor as it is, Is that either the pulley or the timing Mark(on the outside of the block next to pulley) are not correct. I did buy a new marker from a seller on Ebay for the new motor. Maybe its not for my engine? The mechanic noticed the timing drop off when the engine was revved to 4K. He adjusted the timing and Voila! 5400 rpm. He then noticed the front carb running rich no matter where he set the needle.... Paltech Restored Carbs. So now he is rebuilding the front carb and get it working right. On the old engine they were able to get it to rev to 6K with carb adjustments.

I'm hoping this is the cure although now I feel the title of this thread is wrong and I posted my first message in the wrong forum.... Sorry.

All the help and suggestions here have been incredible and I thank all of you.

I will most certainly let you know the Final outcome and steps taken to resolve.

This has been a real mystery. The only thing that is still lingering in my mind is that the old owner of the car said the old motor was doing this same thing when he parked it 18 years ago. I put Different carbs on the old motor since day one when i got the car. Thats the first thing I did was the fuel system and replacing the carbs. There may be some coincidence involved in this mystery. These rebuilt carbs are the same carbs on the new motor now.

Paltech - SU Carbs Round Top ,4-Screw- 425$ micro polished and rebuilt, ready to install with minor tuning and a rich no matter what needle.

[Arne]

From the 9th post in this thread.

Interestingly enough, I have been experiencing the same issue on mine. Felt like a 4000 RPM rev limiter. Just today I finally got a change in symptom by advancing the timing more. My current theory is that the timing pointer is not correct, and that I was running it very much retarded. Try advancing the timing about 10 degrees more than what it is now and see if that helps.

And now:

Some Progress Made.

I went to see the Z this past friday and I got some good news and some bad news. The good news is that the car is revving to 5400 RPM now. The bad news, minor as it is, Is that either the pulley or the timing Mark(on the outside of the block next to pulley) are not correct. I did buy a new marker from a seller on Ebay for the new motor. Maybe its not for my engine? The mechanic noticed the timing drop off when the engine was revved to 4K. He adjusted the timing and Voila! 5400 rpm.

Looks like yours and mine are mostly the same issue after all.

[ChrisZ]

Sean, please post a photo of your timing mark and front pulley, there are two different kinds and they don't mix up.

I don't know of Paltech, but if your car have sat for a while your crappy gas will make the chokes stick and the car running rich, try to clean it up with some acetone so everything moves freely, if you grab your choke at the bottom of the carb and pull it down it should move up freely, do the needles have a satin look ? and is your nozzles out of round and what about the float level, is it adjusted correct.

Chris

[doradox]

In your first post you stated....

Carbs have been swapped.

Sean:bulb:

Have two sets of carbs been used on this new motor?

You also said..

The cam is a performance grind and the car idles great and runs great up to 4K

Have you actually driven the car? I ask because if the base timing is so far off the car won't rev out it should run poorly at all other rpm. Just sluggish all around.

And this has me puzzled..

The mechanic noticed the timing drop off when the engine was revved to 4K. He adjusted the timing and Voila! 5400 rpm.

How did he notice a timing drop off? And what does that mean? The timing should advance as the rpm increases, if not the distributor is bad. Timing effects the vacuum signal to the carbs so fix the timing issue first then the carb issue.

Steve

[Seanw987]

I will take a close up of my pulley and the timing mark . I will have to go down to the shop to take it but I will go today.

No, I havent actually driven the car with new motor yet. So It may be sluggish or less than what it should be.

As far as "Timing Dropping Off". I guess I meant that the mechanic noticed a problem (i wasnt there) with the timing not being correct when he revved it up to 4K. He advanced timing and it performed "better" but not perfect.

The carbs were rebuilt and micro polished by a group named paltech.. yahoo search them if interested in more info. They have a site. The front carb may already be rebuilt and installed by today so there may be some more updates when i return from the shop.

The entire fuel system was nasty when I first got the car. So the first thing i did was to restore/replace all fuel lines and have tank dipped and treated. its as good as new. There was varnish gas when i first got the car. now its just clean as new from tank/s to carbs and all hoses/lines in between.

[doradox]

I will take a close up of my pulley and the timing mark . I will have to go down to the shop to take it but I will go today.

No, I havent actually driven the car with new motor yet. So It may be sluggish or less than what it should be.

As far as "Timing Dropping Off". I guess I meant that the mechanic noticed a problem (i wasnt there) with the timing not being correct when he revved it up to 4K. He advanced timing and it performed "better" but not perfect.

The carbs were rebuilt and micro polished by a group named paltech.. yahoo search them if interested in more info. They have a site. The front carb may already be rebuilt and installed by today so there may be some more updates when i return from the shop.

The entire fuel system was nasty when I first got the car. So the first thing i did was to restore/replace all fuel lines and have tank dipped and treated. its as good as new. There was varnish gas when i first got the car. now its just clean as new from tank/s to carbs and all hoses/lines in between.

Your mechanic can quickly check your timing mark/pointer by taking out the number one spark plug, turning over the engine by hand, and stopping when he sees the piston come up to TDC. It won't be super accurate but if he was careful the marks should be within about +/- 5 degrees of indicating zero or TDC. If so, you should be good.

Steve

[Seanw987]

heres the pulley and the marker. this is not the marker i bought but a marker that the mechanic had as extra or one that came off my old motor. im not sure.

I know its not the new one i bought as i painted that one blue.

[Arne]

IIRC, that style of marker goes on the LEFT side of the engine. The marker for the right side (used on some years) is a single pointer.

Does the pulley have only one mark? Or several?

[Seanw987]

Also , Mechanic told me today he is going to tdc the engine again by hand with the #1 cyl and compression method. this has already been done once but the crank mark was way low, near oil pump last time he checked it. Maybe this is a clue? Revving only to 4500 not 5400 rpm. rebuilding carb did not fix issue. I think cam/crank timing is off.

[Seanw987]

the pulley has one mark. and looking head on at the engine, this marker is towards the left side, about 10 or 11 O'clock position...

Edited March 11, 2009 by Seanw987

[ChrisZ]

Your timing marker should look like this and point to the first grove from left on the pulley at TDC

Chris