Dominator idle adjust on B&M 250 Blower
06-27-2005, 07:55 AM
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Dominator idle adjust on B&M 250 Blower
I'm trying to set up a fountain with a pair of 502 blower motors.
502 blocks, intercoolers, B&M 250 blowers, single Dominator with 4 corner idle screws, MSDs @30 totoal.
The boat cam from sea level, but surges badly at LOTO, 660ft. it's surging from 500-1500.
After MUCH trial and error, I was able to lean out one motors idle screws to get a very nice idle with about 3/4 turn on the secondary screws and 1 turn on the primaries. If I turn any screw even 1/8, it will either surge again or die.
Anyway, I still have to do the other motor. Is there a faster way to do this other than trial and error?
BTW, Setting the second carb the same as the first was not close enogh to eliminate the surge. The owner plans on twin carbs, but not til next year too.
502 blocks, intercoolers, B&M 250 blowers, single Dominator with 4 corner idle screws, MSDs @30 totoal.
The boat cam from sea level, but surges badly at LOTO, 660ft. it's surging from 500-1500.
After MUCH trial and error, I was able to lean out one motors idle screws to get a very nice idle with about 3/4 turn on the secondary screws and 1 turn on the primaries. If I turn any screw even 1/8, it will either surge again or die.
Anyway, I still have to do the other motor. Is there a faster way to do this other than trial and error?
BTW, Setting the second carb the same as the first was not close enogh to eliminate the surge. The owner plans on twin carbs, but not til next year too.
06-27-2005, 08:16 AM
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Re: Dominator idle adjust on B&M 250 Blower
You may want to try a bit more timing and check that the transfer slots are set evenly primary and secondary sometimes you tend to adjust the primary to get the idle were you want it rpm wise and uncover the transfer slot also check what size power valve you have you may be unseating the valve if it's surging that much . Good luck to you Laz Mesa
06-28-2005, 12:05 PM
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Re: Dominator idle adjust on B&M 250 Blower
When you say 30 total, what is your initial? Blower Motors like about 14-18 degrees initial timing but, I wouldn't run over 30 total.
Actually I don't think there is an easer way to adjust the mixture. Just turn each one in small amounts all the way around until you get it.
It's even more fun with 2 carbs.
Actually I don't think there is an easer way to adjust the mixture. Just turn each one in small amounts all the way around until you get it.
It's even more fun with 2 carbs.
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06-28-2005, 02:51 PM
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Re: Dominator idle adjust on B&M 250 Blower
I was planning on checking timing this weekend (no timing gun with me last week). But a well known west coast engine builder/rigger set it up. But when I called and asked about the timing, he said 30 total, and said he didn't care about initial.
07-06-2005, 10:36 AM
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Re: Dominator idle adjust on B&M 250 Blower
Followup.
Primary floats were at midpoint of bowl plug. Got clear sight plugs, adjusted to bottom of hole. It eliminated the gas drip from primaries that was causing it to load up.
BTW Bob, Tbolt IV V6 modules. About 20 initial, 30 total.
Gary
Primary floats were at midpoint of bowl plug. Got clear sight plugs, adjusted to bottom of hole. It eliminated the gas drip from primaries that was causing it to load up.
BTW Bob, Tbolt IV V6 modules. About 20 initial, 30 total.
Gary
