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I can't believe what just happened
- Thread starter 2wrench
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TR3driver
Great Pumpkin - R.I.P
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When you get that timing light, be sure to check if your centrifugal advance is working properly. Hopefully your mechanic checked it, but he may have assumed that it was OK.2wrench said:
If you think it might be mixture, you could try going a full turn richer on the carb needle adjustment and taking a drive. That will make it too rich at idle; but if it perks up noticeably at higher rpm (compared to before making the change) you may need different needles or lighter springs.
poolboy
Yoda
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Another thing to check, assuming that the timing is not the culprit is the condition of the Diaphram that is attached to the air valve piston. If there is a tear or hole, the carbs won't perform under acceleration.
Just remove the 4 screws on top of the carb, remove the cover and the spring. Then you can lift out the air valve and the diaphram for inspection..
There will be, or should be, a few cc's of oil in the damper so watch that if you tilt the assembly.
And when you replace the air valve/ diaphram, be aware of the locating tab on the rim of the diaphram and that it must fit back into a slot in the carb body.
Just remove the 4 screws on top of the carb, remove the cover and the spring. Then you can lift out the air valve and the diaphram for inspection..
There will be, or should be, a few cc's of oil in the damper so watch that if you tilt the assembly.
And when you replace the air valve/ diaphram, be aware of the locating tab on the rim of the diaphram and that it must fit back into a slot in the carb body.
R
RonMacPherson
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Guest
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If your total advance is 44 degrees before TDC, start saving for an engine rebuild. Anything over 35 is getting close to preignition/detonation range. And if the compression has been raised..... Hole in piston time soon.
It might be a good idea to contact both your cam seller and Jeff at Advanced Distributors for their input on maximum total advance....
It might be a good idea to contact both your cam seller and Jeff at Advanced Distributors for their input on maximum total advance....
44 is way to much by 2,000rpm
OP
2wrench
Luke Skywalker
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Okay. A whole lot here. Thanks, everybody. I moved the wires back
and set the timing where it seems to want to run and start nicely.
Idles pretty nicely at 900 to 1,000 rpm's.
Timing has been put at 24 degrees before TDC.
As for the carbs, I can't get a good look at the origin of the leak.
Seems like maybe I should buy a rebuild kit and tear into 'em.
This one should set me back a good number of weeks to months.
There is so much to consider with the carbs, seems to just go for
the rebuild would be the thing to do.
Had a friend suggest checking E-Bay for already rebuilt carbs, but
afraid of what I might get. If it were somebody from our Forum,
I'd have no problem, but I'd have to think twice about just anybody.
I have considered fast forwarding on to Volume III of the carb rebuild
site and glean what I might look at. Maybe they don't need all that.
and set the timing where it seems to want to run and start nicely.
Idles pretty nicely at 900 to 1,000 rpm's.
Timing has been put at 24 degrees before TDC.
As for the carbs, I can't get a good look at the origin of the leak.
Seems like maybe I should buy a rebuild kit and tear into 'em.
This one should set me back a good number of weeks to months.
There is so much to consider with the carbs, seems to just go for
the rebuild would be the thing to do.
Had a friend suggest checking E-Bay for already rebuilt carbs, but
afraid of what I might get. If it were somebody from our Forum,
I'd have no problem, but I'd have to think twice about just anybody.
I have considered fast forwarding on to Volume III of the carb rebuild
site and glean what I might look at. Maybe they don't need all that.
D
DougF
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Guest
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If I remember correctly, '74 Strombergs have fixed needles due to pollution constraints. If you are running the original carbs on a higher performance engine, you could be running out of fuel at 3,000 rpm.
If you go the ebay route, and are not concerned about originality, buy an earlier set that doesn't have so many vaccuum lines. 74's had more vaccuum lines, fuel traps and other areas to cause problems than any other year.
I solved several problems on my old '74 when I went to carbs from a '72.
If you go the ebay route, and are not concerned about originality, buy an earlier set that doesn't have so many vaccuum lines. 74's had more vaccuum lines, fuel traps and other areas to cause problems than any other year.
I solved several problems on my old '74 when I went to carbs from a '72.