Bobcat 642B rough running question

Hello all! I'm new to the forum today. I have owned a 642B for a couple of years now and when the dash fell out and blew the fuse I decided to give the ol' boy a tune up! Well, put in a new fuse holder, cap, rotor, points, plugs, wires. You would think that would have been easy. Seemed like I had no spark. after I put my old stuff back in I think I got lucky with the points and it started but ran really rough. I then put the new cap on the new points gapped to the same as I got lucky with the old ones and It ran. Now it seems to blow black smoke and run like a pooch. Now where near the rpms that I had prior and sputters a bit. I belive that I have the wires going to the proper place with help from my bobcat dealer. I'm new to points could a small adjustment to this cure my poor running. It also does not like to run with idle all the way down. any help will be greatly appreciated! Thanks and I have learned alot so far from the threads Ben

Check to make sure you have the plug wire routed right, the firing order should be cast into the manifold. Make sure the point gap is right , don't guess at it or if you have to put the points on top of a lobe and set to .015 or .020 that should get you going. Make sure you did not disconnect the vacuum advance hose on the distributer The gap depends on which engine you have in the machine.

jerry said:

Check to make sure you have the plug wire routed right, the firing order should be cast into the manifold. Make sure the point gap is right , don't guess at it or if you have to put the points on top of a lobe and set to .015 or .020 that should get you going. Make sure you did not disconnect the vacuum advance hose on the distributer The gap depends on which engine you have in the machine.

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Thanks for the reply. I have it set to .020 at TDC. It runs now and does idle "very low" but runs. If I work the controls and labor the hydralics it bogs and seems to miss. The confusing part is that prior to the "tune-up" it worked pretty good. with the hose hooked up could it still be pulling air on the vacuum line being old? thanks again! Ben

ashippun bobcat said:

Thanks for the reply. I have it set to .020 at TDC. It runs now and does idle "very low" but runs. If I work the controls and labor the hydralics it bogs and seems to miss. The confusing part is that prior to the "tune-up" it worked pretty good. with the hose hooked up could it still be pulling air on the vacuum line being old? thanks again! Ben

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Take the hose for the advance off on the carb/manifold end and apply vacuum to it to make sure the diaphragm inside it is good. If your plug wires are old maybe replace them as when you moved them they may have cracked. Start right with the cheap stuff at the bottom. There is a mechanical advance in the bottom of most distributors, make sure it is working, then where the point wire passes thru the body it can short. Did you replace the condensor? They do get tired too.good luck with it , when you get done it will probably work and may be hard to say what fixed it. Does it run smooth at fast idle with no load?

jerry said:

Take the hose for the advance off on the carb/manifold end and apply vacuum to it to make sure the diaphragm inside it is good. If your plug wires are old maybe replace them as when you moved them they may have cracked. Start right with the cheap stuff at the bottom. There is a mechanical advance in the bottom of most distributors, make sure it is working, then where the point wire passes thru the body it can short. Did you replace the condensor? They do get tired too.good luck with it , when you get done it will probably work and may be hard to say what fixed it. Does it run smooth at fast idle with no load?

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So after taking the cap off about 100 times I decided to go back to the spec sheet that the bobcat dealer printed off for me. I found that I had the #2 and #3 spark plug wires reversed! I reached inside the door turned the key it not only started but idled perfectly! Thanks for all the help and input. This is a great forum and I'm sure I will use it again and again! Thanks!!! Ben

ashippun bobcat said:

So after taking the cap off about 100 times I decided to go back to the spec sheet that the bobcat dealer printed off for me. I found that I had the #2 and #3 spark plug wires reversed! I reached inside the door turned the key it not only started but idled perfectly! Thanks for all the help and input. This is a great forum and I'm sure I will use it again and again! Thanks!!! Ben

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Hate it when that happens, glad you where able to find the problem. We have all done that before. Good luck.