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I can't believe what just happened

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2wrench

2wrench

Luke Skywalker
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Paid a Pro mechanic to look at timing on Dyno machine.

Gave him the specs for the BP 270 cam.

Watched in amazement (thinking I was learning something,
here,) while he pulled each spark plug wire on the dizzy
cap and moved them over one to the right.

He just changed the firing order, right????

Then he sets my timing at 24 degrees whichever way, before
or after TDC. Car has vibration on acelleration.

Tells me my carbs are leaking raw fuel. That I agree with.
Hoped I could get by without rebuilding them.
Quotes 800-plus to rebuild and set carb. The car is burning
fuel like a house on fire before he worked on it.

If the carbs need rebuilding, I suppose I should consider
a new set of SU's.

Money is a factor, again.

I'm thinking to walk those spark plug wires right back
where they started and put the timing back more like it
was and start over with a different mechanic. I know
of a good one, it's just the travel and getting his time....
oh, yeah, and the expense.

Any suggestions?
 
2wrench,
Last I looked getting a couple of carbs rebuilt by the top 4 isn't close to that much money.
Why did he change the firing order??
 
Moving each wire one spot to the right doesn't change the firing order per se, but it would effectively advance the timing about 60 degrees. Presumably he compensated for much of that with his resetting the timing. Without being there, though, I've no idea why he might have gone to all that trouble.

As for the carb rebuild, shop around. You can probably find a cheap round-trip flight to Joe Curto's shop, where you could hand-deliver your carbs, watch Joe work his magic, and then bring them back home with you, all for less than $800. ;-)
 
Moving all the wires one post doesn't change the firing order; just the timing.

Under what conditions was the 24 degrees measured? If that is initial advance, it's huge. If it's total advance at, say, 3500 rpm then it seems a little low (which might be appropriate for your engine).

Not sure offhand which carbs you are starting with, but it should be well within any DIY's ability to get them to stop leaking raw fuel (unless a casting is cracked or broken). Unless you need to tackle the throttle shafts, a "rebuild" is pretty trivial. Hopefully I don't need to point out that leaks can waste a HUGE amount of fuel, not to mention being dangerous in more ways than one.

So, my suggestion is to get the carbs to stop leaking first. If these are ZS carbs, then the most likely problem IMO is just crud caught in the float valve. Try cleaning it first, then replace if necessary. Ideally you should have a rebuild kit on hand, but I'd tackle that even without new parts available.

For the timing, get a timing light. A basic, inductive pickup, DC powered timing light shouldn't cost more than $20-30 and IMO is a required tool for old cars. While I have nothing against the expensive computerized ones, the basic tool will do. This one looks like a good candidate
https://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3343

Now you can check the advance yourself, and try different settings to see what the engine likes.

But fix those carbs first !
 
That was the initial advance. He says the overall advance at 2000 rpm's
is putting it at 44 degrees.
 
2wrench

Am I confused or is this a new (rebuilt) engine?
The only reason I can think of for doing that, (moving wires) is to compensate for a bad timing chain.
In 44 years of this business, I've never had to do that.
JMHO-LOOK FOR A NEW GUY!

Dave :savewave:
 
Yeah, Dave, new rebuilt. I think I will look to somebody else.
I have a mind with Randall's comments to buy the carb rebuild kit and
go for it.

The Forum has kept me pretty good so far. I mean, the darned thing
starts and runs....

I was advised to stay away from the tranny so I did. If Randall thinks
I can do the carbs, I suppose I'm game for a try. After the engine,
why not?

I just always thought carbs were pretty tricky.
 
Could it be that the HT leads were struggling to reach the spark plugs with the correct timing and by moving them they fitted better? Otherwise I can't think why he would have done that. Did you ask him?

Yes, try rebuilding the carbs. You will find that it is a quite easy and satisfying job.
 
tdskip said:
Why did he change the firing order?
[/quote

I suppose to change the timing. Had me baffled, but I'm
still just a baby mechanic.

This is my "I need a laugh," cup for coffee. I'm pouring me
one....

P1010002-57.jpg
Click to expand...
 
2wrench said:
Quotes 800-plus to rebuild and set carb.
Click to expand...
Before we beat up too badly on this guy, perhaps we should ask if that includes tuning on the dyno. This is a modified engine, after all, so some tweaking of the mixture throughout the range would likely be helpful. I doubt that is included in a mail-order rebuild.

Not that it's a requirement, just wondering if we are comparing apples to oranges.
 
2wrench said:
I just always thought carbs were pretty tricky.
Click to expand...
Well, have a look at Nelson's articles on the subject (assuming you have the stock ZS carbs). These are by far the best, clearest articles I know of.
https://www.buckeyetriumphs.org/technical/technical.htm

But keep in mind that you don't necessarily need to do everything that Nelson describes (including the throttle shaft stuff). Almost certainly your problem is just the fuel level being too high, which is only controlled by the float and float valve.

And the problem might not even lie within the carbs (especially if both of them are doing the same thing). Could be the fuel pressure is too high for some reason. Dale isn't the only one to find a "new" fuel pump that put out too much pressure!
 
It would be a good idea to determine if you can where the gas is leaking from.
If the engine is not running and you see gas dripping from the bottom of the float chamber then it may just be the O-ring seal.
If you see gas coming up the jet when the engine is running, then I'd suspect the needle valve like Randall suggested.
Regardless, I agree that with the help of the Buckeye link that you can replace all the parts that need replacing and more, including and recommended, the throttle bypass diaphram for under 100 dollars
Rearranging the plug wires ? So now either cylinder #5 or cylinder #4, depending upon which direction he went, is firing instead of #1 ?
 
NickMorgan said:
Could it be that the HT leads were struggling to reach the spark plugs with the correct timing and by moving them they fitted better? Otherwise I can't think why he would have done that. Did you ask him?

Yes, try rebuilding the carbs. You will find that it is a quite easy and satisfying job.
Click to expand...

In terms of why he did it, he indicated to me that the wires attached to the dizzy
were stopping him from putting the dizzy where it needed to be. He suggested also at
one point removing the tach cable, as if to ask what I thought. I said cool. Don't know if he actually disconnected that tach cable or not. Seemed like he was going to, but then moved spark plug wires, instead. If he took it off, he sure put it back on very quickly.
 
2wrench said:
In terms of why he did it, he indicated to me that the wires attached to the dizzy
were stopping him from putting the dizzy where it needed to be.
Click to expand...
Which makes perfect sense, in terms of getting the static advance that high. Of course, you could accomplish the same thing by taking the pedestal apart and moving the gear by a tooth or two, but swapping the wires is quicker (and cheaper).
 
poolboy said:
then it may just be the O-ring seal.
Click to expand...
Oh yeah, good point. I forgot about that O-ring.
 
Brosky said:
I hope that you didn't pay him any money.
Click to expand...

Sorry, Paul. Yeah, paid $45 for half-hour machine time.

Found a spark plug wire off, after taking a look. Car ran
better, but still doesn't seem to have the push after
3000 rpm.
 
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