2F runs super rough, Carb problem?

cruiserhead75 · 08-07-09, 05:49 PM

Hello all,
I am trying to help my cousin with his FJ60 motor issues and need some suggestions. He has a rebuilt 2F motor and a new carb, yet we cannot get his cruiser to run well. It always takes full choke to start it, once it is started, throttle must be applied to keep it running until it is somewhat warm, and once we turn the choke off, and it can idle by itself, it misses horribly. I set the idle as best i could at about 610-650, and the ignition timing advance at 7.5 degrees before top dead center. Aside from missing all the time, when the motor is reved, it does not return to idle immediately, it slowly returns to idle. Do i have the timing right, any suggestions?
-Ian

D'Animal · 08-07-09, 06:03 PM

Adjust the valves.

When you set the timing, unplug and block the vacuum lines connecting to the distributor.

How did it run before the new carb?

cruiserhead75 · 08-07-09, 06:04 PM

Hello all,
I am trying to help my cousin with his FJ60 motor issues and need some suggestions. I know this is the 40 forum, but no one in the 60 forum is responding. He has a rebuilt 2F motor and a new carb, yet we cannot get his cruiser to run well. This is the second carb-rebuilt by Cruiserparts.net. It always takes full choke to start it, once it is started, throttle must be applied to keep it running until it is somewhat warm, and once we turn the choke off, and it can idle by itself, it misses horribly. I set the idle as best i could at about 610-650, and the ignition timing advance at 7.5 degrees before top dead center. Aside from missing all the time, when the motor is reved, it does not return to idle immediately, it slowly returns to idle. Do i have the timing right, any suggestions?
-Ian

Poser · 08-07-09, 06:10 PM

Quote:

Originally Posted by cruiserhead75

Hello all,
I am trying to help my cousin with his FJ60 motor issues and need some suggestions. I know this is the 40 forum, but no one in the 60 forum is responding. He has a rebuilt 2F motor and a new carb, yet we cannot get his cruiser to run well. This is the second carb-rebuilt by Cruiserparts.net. It always takes full choke to start it, once it is started, throttle must be applied to keep it running until it is somewhat warm, and once we turn the choke off, and it can idle by itself, it misses horribly. I set the idle as best i could at about 610-650, and the ignition timing advance at 7.5 degrees before top dead center. Aside from missing all the time, when the motor is reved, it does not return to idle immediately, it slowly returns to idle. Do i have the timing right, any suggestions?
-Ian

One thread, one section.

Someone has not given you an answer in less than fifteen minutes?

Get a fawking grip dude.....

What would you have done 25 years ago?

As far as your question:

Sounds to me like you have vacuum leaks.

Get the engine idling best you can, grab a can of carburetor cleaner and spray along the base of the carburetor and along the cylinder head where the intake manifold meets the head.

Report back what you find.

cruiserhead75 · 08-07-09, 06:16 PM

I have made a few posts in the FJ 60 forum before,.....receving little to no help. I will look into the vacuum leaks and make sure the valves are in check. Thanks for the friendly advice.

cruiserhead75 · 08-07-09, 06:20 PM

It ran decent after the motor swap. He put a rebuilt carb on and it ran like a dream for about a week, then started missing and operating rough "all of the sudden". So he tried ANOTHER rebuilt carb, and that didnt seem to make a difference at all.

Poser · 08-07-09, 06:22 PM

Quote:

Originally Posted by cruiserhead75

I have made a few posts in the FJ 60 forum before,.....receving little to no help. I will look into the vacuum leaks and make sure the valves are in check. Thanks for the friendly advice.

It typically works better to start your own thread instead of expecting people to pay attention to a question in an existing thread. Unless you have another user ID out here, you have not started any threads in the 60-tech section until today.

Report back to this thread what you find out.

Poser · 08-07-09, 06:24 PM

Is the distributor cap cracked/broken?

2mbb · 08-07-09, 07:46 PM

Quote:

Originally Posted by D'Animal

Adjust the valves.

When you set the timing, unplug and block the vacuum lines connecting to the distributor.

Yeah. Start with the basics...Make sure the valves are adjusted properly.

Make sure you don't have any vacuum leaks or disconnected vacuum tubes. If you have fully smoged vehicle, then use the attached diagrams or get the emissions manual to make sure things are connect properly.

When you adjust the timing, disconnect and plug the vacuum lines going the advance diaphragm(s). There are two marks on the fly wheel that you see through the timing window: a straight scribed line (top dead center) and an embedded sphere or "bb" (7 degrees before top dead center). You align the pointer with the "bb" to set the timing. If you can't find the marks, its easier to remove the clutch inspection cover under the bell housing and rotate the fly wheel until you see the marks.

Good luck.

inkpot · 08-07-09, 09:02 PM

Quote:

Originally Posted by cruiserhead75

It ran decent after the motor swap. He put a rebuilt carb on and it ran like a dream for about a week, then started missing and operating rough "all of the sudden". So he tried ANOTHER rebuilt carb, and that didnt seem to make a difference at all.

Howdy! Is the idle solinoid working? It sounds like NOT!, so you have the idle speed jacked way up to compensate for it. John

PAFJ · 08-07-09, 09:10 PM

Get a vacuum gauge (one of the best tools for diagnosing problems w/ these engines) and hook it up to the intake manifold. A healthy engine should read 19-20 Hg on the gauge.

Plus x2 on what everyone else said.

Good Luck-

Butt Ugly Chuck · 08-08-09, 03:03 AM

Quote:

Originally Posted by Poser

Sounds to me like you have vacuum leaks.

Get the engine idling best you can, grab a can of carburetor cleaner and spray along the base of the carburetor and along the cylinder head where the intake manifold meets the head.

Report back what you find.

Quote:

Originally Posted by 2mbb

Make sure you don't have any vacuum leaks or disconnected vacuum tubes. If you have fully smoged vehicle, then use the attached diagrams or get the emissions manual to make sure things are connect properly.

Quote:

Originally Posted by PAFJ

Get a vacuum gauge (one of the best tools for diagnosing problems w/ these engines) and hook it up to the intake manifold. A healthy engine should read 19-20 Hg on the gauge.

X2 what they all said. Sounds very symptomatic of a vacuum leak to me.

Quote:

Originally Posted by cruiserhead75

It ran decent after the motor swap. He put a rebuilt carb on and it ran like a dream for about a week, then started missing and operating rough "all of the sudden". So he tried ANOTHER rebuilt carb, and that didnt seem to make a difference at all.

It's common for the manifold bolts to need re-torqued after a few running cycles and is just one possible source for a vacuum leak.

Best of luck! Let us know what you find.

Butt