Poor running 70

[Resting Relics 1]

Hey guys,
I've got a Oliver 70 that was given to me by an old friend just before he passed away. It was stuck but overall not in to bad shape. It was all there and since it was stuck I was not sure what else might be wrong inside. I pulled the engine apart to free up. Put in new rings,and bearings, honed out the cylinders which cleaned up pretty well and ground the valves. Did a complete tune up for the distributor ignition ie: points, condensor, plugs, cap, rotor, and coil. Set the timing and She started right up, but runs poorly. When I got looking more closely I found a crack in the intake manifold so I replaced both intake and exhaust manifolds which I got from Steiner. Still it runs no better. I checked compression and all six are around 100 pounds. I took the carb apart. It actually looked pretty good. Put a kit in it. Still no luck. It won't pull under load, idles rough and runs rough when throttled up. I bought a rebuilt carb from this site and that makes no difference. I'm at my witts end. I remember working on the neighbors farm when I was boy. He had two 70's and did next to nothing to them and they purred like a kitten. I've spent a small fortune on this old girl and can't believe I can't make it run nicer. Any Thoughts about what I might be missing or some issues these old 70's might have had that could cause her to run so bad? Any help would be appreciated.
John

 

[RCP]

Are you sure the ignition timing and firing order are correct. A friend had a 70 and could not get it to run correct, turns out he confused the wires when going through the tube from the right side to the left side.

Rich

 

[Resting Relics 1]

RCP,
If I pull the choke out a little and do a power brake to put a load on it she will pull fairly well till she starts to lose rpm then she just quits. But she does hit on all cylinders while this happening. It seems like a carb problem but with two different carbs and one of them professionally rebuilt it don't see how it can be.
I'm truly stumped. I know everything can't be right or she would run but so far everything I've tried doesn't help.
John

 

[J.Wondergem]

Squirt some starting fluid around the edges of the intake while it's runnin, to prove your not drawing air.

 

[Anonymous-0]

Get yourself a vacuum gauge and plug it in and see what you have. If there is no 1/8 inch pipe plug in the intake manifold above the carburetor flange, drill and tap one.

 

[Resting Relics 1]

Mr Schwiebert,
What should I expect to see for inches on the vacuum gauge. It does appear to have a good amount of draw at the carb intake. I'll get this done this weekend and let you know what I find.
Thanks, John

 

[J.Wondergem]

When you put the vacuum gauage on and running, notice the numbers, also if the needle drops and picks back up, or fluctuates. Then post back with the details.

 

[J.Heikk]

Is it possible there is restricted flow of the gas? I'm not familiar with the 70, but is the line or bowl assembly partially plugged with rust perhaps? Is the vent on the tank cover plugged?

 

[ollie gm]

Your problems matched mine almost perfect except I didn't do the engine work myself. I fought my 70 for a couple of months until the gas tank was mistakenly completely filled. The next time I started it, the engine ran near perfect. I adjusted the mixture screws and then it did run perfect. It seems that the carb was being starved for fuel as the needle/seat needed a little more pressure behind it to hold the right level. Good luck.

 

[Anonymous-0]

John: Send me an e-mail address or a phone number and I will send you a chart.

 

[Resting Relics 1]

Thanks,
Send to [email protected]. I don't think this manifold from Steiner has a port in it so I'll probably have to drill and tap one. I've even bought another whole round of tune-up stuff from the local dealer who used to sell Oliver's including new wires with no success. I've tried with the gas cap off to rule out venting as a problem and have even run the tractor off my made up gas can directly into the carb to rule out the tank and fuel bowl even though they look good. The only thing I haven't done is check for vacuum leaks like you guys have suggested which I suppose could be a problem. I'll do that and get back to you.
John

 

[ollie gm]

You've got a lot of good input here. Before you do some drilling try introducing an alternate fuel. If the problem is fuel only, puff a little starting fluid near the intake and the engine should settle out and run smooth for a couple of seconds. Or, use propane, I take the jet out of my propane torch and blow it directly into the carb. If there are fuel issues this should be a temporary fix.

How good are your ignition parts? A sloppy distributor bushing can give you a different timing value to each cylinder. Are all of your primary wires terminated correctly?

 

[Resting Relics 1]

Thanks guys for your suggestions. I'll try checking the vacuum and see what I get. I didn't try feeding her some ether but I'll do that also to see if it makes a difference. Ollie, I put two different ignition stuff in over the last couple months as I explained earlier with no difference. It acts just like the carb needs to be adjusted but with two different carbs and one professionally rebuilt with no difference makes me thinks you guys may be on to something with the vacuum issue. I'll get back when I've had a chance to work on the old girl again
John