Weekend tune up.

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rov716y

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I brought my bus a few weeks back, not owning one before or driving many , when looking I don't have much experience with the engines. But I knew he wasn't running right, he had a miss fire under load at low rpm, stalling at junctions and smelling very rich.

After reading a manual on the tune up process this weekend I set about sorting him out.

Starting with the valve clearances. 0.15mm was the ideal clearance (from what I've read), all 8 valves were too tight, most not having any clearance at all. So the were all adjusted.

Then on to the points. Which again was 0.15mm to my surprise they were spot on, but the bit of white plastic (nylon?) That retained the spring bit that rubs on the shafts wasn't seated back so I clipped it home, I checked the vacuum advance to and it works perfectly and holdo vacuum.

So time to strike him up and adjust the timing I checked it before I did anything and according to my timing strobe it was set at 55° advanced!!!!. So I went to loosen it off to adjust but the distributor had a lug that blocked the 10mm nut on the clamp, so I had to completely remove the distributor to loosen it. And once fitted back on with the clamp loose I set the timing to 6° advanced which he ran nicely at, but once the choke kick out he stalled. I managed to get him running nicely at 15° advanced and at that I cold get a socket on tighten the 10mm but on the clamp.

As the choke had been kicking in when he was warm I turned it so it was backed off quiet a bit, I'll have to wait till cold weather to see how he starts.

I then adjusted the carb, set the idle jet then the idle speed.

I took him for a 30min drive round town then a 10 mile a road drive. He never missed a beat no stallingamells at junctions, a pleasure to drive. He now has really good throttle response and feels quicker. Didn't smell like he was over feeling so fingers crossed I've done some good.
 
Is 15 degrees advanced correct for your distributor? Seems an odd number.


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Was the vaccum plugged when setting the advance? What was the max advance at 3500 rpm ish ?
 
Vacuum wasn't unplugged. I've read done with it off and he times up at tdc happily. And when reconnected is showing 25 advanced. I don't have a tacho so can't judge the Rpms.
 
Don't know what dizzy you are running so don't know what the timing should be. However if its a vacuum advance dizzy (i.e. not 009) check whether you time with the vacuum disconnected or not ( for most but not all you should disconnect) and if disconnected plug the port on the carb. Set the revs at idle to the correct speed and time dizzy as recommended for the particular dizzy (for SVDA 7.5 degrees). Check the max advance at 3500rpm (when it stops advancing) to ensure it is not over advanced. (28 - 30 degrees).
 
It's an svda. Stalled today at a set of lights. So somethings still not right. I'm going to double check everything and give him an oil change this weekend.
 
What brand of distributor is it?

The most important timing process is the max advance one. Rev the engine up until it stops advancing and see what reading you get. For most SVDA dizzy's AFAIK, this should be somewhere around 30 degrees. You will need to check whether or not the vac can needs plugging for this test - once you know what it is, there's plenty of info on the net. You may find that the idle advance sits at a different value to what you're expecting, but don't worry so much about this. I had a dizzy where the mech was sticking, so I could get the correct max advance, but at idle it was sitting somewhere around 12 - 15 degrees.


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