Lotsa pressure

nwpaironhead · #1 10-02-2009, 03:06 PM

I just got my first build running . Woohoo!!! Got a few issues. First, I changed fluids before startup. Drained crank case and oil tank and put in 3 quarts of Castrol GTX 20 W 50. Oil light goes out as soon as the motor cranks, but upon firing i think I'm building WAY too much crank case pressure. Every time I crack the throttle, the vent tube sprays, leaving a splatter mark on the floor. and after shut down I checked the oil and its almost overflowing out of the tank. I pulled the tach drive plug to see if the oil level would drop back down and nothing happened, so I moved on to the oil cooler. It was dead cold. I put the oil line without the tube in the tank to the pump. the small is the vent and the large goes to the cooler. Any ideas of what I did wrong? Oh also , the motor sat for 10 or 11 years. When I pull the plugs and put my fingers on the holes I can't stop the compression from escaping past my digits so I dont think the positive crank pressure is caused by blow by.

Second, the bike is running Really rich. It's shooting black smoke and flames from both pipes. I re-built the carb. (a Bendix-Zenith...ya I know) I dont know what it came off of. I have the accelerator pump pin in the top hole. Too much fuel? Will I need to find a jet kit? I am going to switch to a Mikuni as soon as I can afford to but I really wanna ride sooner than that.

Thank you all for any help.

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nwpaironhead · #2 10-02-2009, 03:09 PM

Oh ya, Forgot to mention. It is a '73 XLCH. And the engine it basically stock. Heads and top end were re-buitl about 200 miles before the previous owner put it in storage and the bottom end has about 1000 miles on it

prodrag1320 · #3 10-02-2009, 03:37 PM

sounds like your lower end was full of oil (from sitting)add more oil,oil pumps out of lower end back into tank,now you have twice the oil.put about 1 quart in tank,start it,let the oil come out of breather,keep an eye on level in tank,should start returning oil to tank when started(dont worry about oil comming out of breather,breathers doing what its suppost to)once the oil gets out of the lower end it should be fine.refill oil tank to proper level.shit can the bedix carb.we have real good luck putting used CV carbs off later HD`s on iron motors(cheap too)
kirby
www.veetwinperformance.com

IronMick · #4 10-02-2009, 04:44 PM

+1 on the CV carb. There are other choices which yield marginally better performance, but you have to spend a lot more $s for those. eBay between $40 and $100 for a CV. Be sure to get one that has the accelerator pump. The first year, about 1989, did not have one.

piniongear · #5 10-02-2009, 06:37 PM

Second, the bike is running Really rich. It's shooting black smoke and flames from both pipes. I re-built the carb. (a Bendix-Zenith...ya I know) I dont know what it came off of. I have the accelerator pump pin in the top hole. Too much fuel? Will I need to find a jet kit? I am going to switch to a Mikuni as soon as I can afford to but I really wanna ride sooner than that.

I may have the solution for your carb problem, but no guarantees.
If the bike has sat for some years without being run most likely a few things have happened during that time.

The oil has drained from the oil tank down into the bottom end. When you crank up the engine oil pukes out the breather tube.
DO NOT REMOVE ANY PLUG YOU MAY FIND ON THE UNDERSIDE OF THE CRANKCASE! To do so may ruin the crankcase. This is not a drain plug, should you see such a plug on yours.
Just run the engine until the oil stops puking out the tube and watch the oil level in the oil tank to make sure there is oil in the tank at all times.
The Bendix.....
Yours is either a fixed jet or an adjustable main jet carb. A Bendix is made both ways. An adjustable jet carb will have 2 needles on the top. A fixed jet carb will have only 1 needle and this is located close to the imlet manifold flange.
Here is a pic of my adjustable main jet Bendix..........

There is an O ring that fits into a groove at the top of the main jet adapter located inside the float bowl chamber. It screws into the center hole pictured here on the bottom of the carb.....

The O ring degrades over time and once degraded, it will allow raw fuel to enter the venturi and cause a super rich condition. Here is a pic of mine and the condition I found it in the first time I encountered the 'O ring' problem........

The fix is to go to Lowes plumbing department where the fawcett parts are kept. You want to buy a packet of (10) #5 or #6 O rings. I forget which size is correct. These will cost you about $1.29.
Put one in your carb and put it back together. Cheapest fix you will ever have on a Harley!

And here are the tuning instructions for your Bendix................Page 1

And page 2.......

That should help get you going.......... pg

nwpaironhead · #6 10-03-2009, 10:45 AM

Thank you guys SO much! Uh, piniongear , what happens if I do remove and replace the thing that looks like a drain plug? Up towards the front of the crank case. I kinda did that before I posted this thread. The bike has been running several times since and there is no bottom end noise. Did I get lucky or is there a catastrophe on the way?

nwpaironhead · #7 10-03-2009, 10:51 AM

all of the carb info is extremely helpful! Brands sources, and cheap fixes. I do have the adjustable Bendix. It has a new o-ring on it , but is not set near what the instructions you(pinion) sent recommend. Gonna try setting it there and hopefully don't unleash the shiny parts because of the drain plug thing. Oh, and after taking some measurements , I don't think I can fit a Mikuni on the bike due to where my petcock is. Any thoughts on S&S?

piniongear · #8 10-03-2009, 11:21 AM

Quote:

Originally Posted by nwpaironhead

Thank you guys SO much! Uh, piniongear , what happens if I do remove and replace the thing that looks like a drain plug? Up towards the front of the crank case. I kinda did that before I posted this thread. The bike has been running several times since and there is no bottom end noise. Did I get lucky or is there a catastrophe on the way?

I have to say you were VERY lucky if the plug does not leak now.
It sounded like you had removed this plug. Quite a number of people have done the same thing, and many regret doing so.

As I have said before, this 'plug' was how Harley decided to fill a hole that was needed during the manufacture of the engine. I do not know the details, but a machining operation was required and they chose to close off the hole with a plug. It was no doubt a cost issue. They ran the plug into the hole for a one time install and it sealed.

Next thing to happen is..... later, an owner has his base 'load up' and thinks this plug was put there to drain accumulated oil from the case.
The cast aluminum crankcase is perhaps 3/8 inch thick at where the plug sits. On top of that, your flywheels are sitting right on top of the plug, perhaps as close as 1/4 inch away.
This prevents you from 're-tapping' the hole to attempt to renew the threads. The crumbly aluminum is not kind to that kind of thing anyway, it is just as well.
So if you remove the plug, 99% of the time the threads crumble and the plug fits very loosely, if at all. It always leaks too.
So consider yourself lucky this time and never remove that plug again.............. pg

piniongear · #9 10-03-2009, 11:37 AM

Quote:

Originally Posted by nwpaironhead

all of the carb info is extremely helpful! Brands sources, and cheap fixes. I do have the adjustable Bendix. It has a new o-ring on it , but is not set near what the instructions you(pinion) sent recommend. Gonna try setting it there and hopefully don't unleash the shiny parts because of the drain plug thing. Oh, and after taking some measurements , I don't think I can fit a Mikuni on the bike due to where my petcock is. Any thoughts on S&S?

A Mikuni should fit if your petcock is on the rear right side of the tank. It is close, but it should fit.
A bigger issue is getting the top of the Mikuni to clear. The carb is OK but the throttle cable almost has to have a 90° elbow on the cable.
So if you buy a Mikuni, make sure it has the throttle cable elbow. Most are sold without it. The elbow actually comes with the cable. Modern editions probably allow you to remove the cable from the elbow but I have a 1973 issue and the cable cannot be pulled through the elbow. I do know that you can now buy the elbow as a separate piece, so that indicates it can be installed on a throttle cable. Be aware though, to do so requires a longer cable (or a shorter housing) to use on a cable not originally intended for the use of an elbow.

Pics of mine are attached.........

pg

nwpaironhead · #10 10-03-2009, 01:18 PM

Aah I see the elbow . Thanks, and something I hadnt thought of is by putting theadapter in, it spaces the carb out a little , gaining a little more room for the carb body and the petcock. Thanks! And after reading the info on that "plug" I REALLY feel lucky! Won't do that again!