madkaw Posted Wednesday at 02:42 PM Author Share Posted Wednesday at 02:42 PM On 5/17/2025 at 2:33 AM, jonbill said: It's a welded p90a. I think the ports are 38mm. I think they must be as big as they can be since the head bolt holes broke through when we drilled them for m12 bolts. Did you have to use the air bleeds to balance ports ? I tried opening one up and didn’t get any response in the air . Quote Link to comment Share on other sites More sharing options...
jonbill Posted Thursday at 05:56 AM Share Posted Thursday at 05:56 AM Yes I did on the FAJs, I just about got the amount of adjustment I needed. Quote Link to comment Share on other sites More sharing options...
madkaw Posted Thursday at 08:41 PM Author Share Posted Thursday at 08:41 PM 14 hours ago, jonbill said: Yes I did on the FAJs, I just about got the amount of adjustment I needed. I don’t need much and it’s just on the first ITB. Maybe really have to crank out the bleeder to get anything out of it ? Quote Link to comment Share on other sites More sharing options...
jonbill Posted yesterday at 05:55 AM Share Posted yesterday at 05:55 AM I don't really remember I'm afraid, but I know there wasn't a lot of adjustment available. Have you looked at recentering the throttle plates to see if you can get more consistent air flow when closed? Quote Link to comment Share on other sites More sharing options...
madkaw Posted 18 hours ago Author Share Posted 18 hours ago 19 hours ago, jonbill said: I don't really remember I'm afraid, but I know there wasn't a lot of adjustment available. Have you looked at recentering the throttle plates to see if you can get more consistent air flow when closed? I guess I don’t know how that’s done and what it does . I run cable that moves first ITB that moves the rest . The first ITB needs more air but there’s no way I can see to adjust its linkage without moving the others . I hooked up the cable and this engine started and idled great - so no real complaints ! Quote Link to comment Share on other sites More sharing options...
jonbill Posted 12 hours ago Share Posted 12 hours ago (edited) There should be adjuster like this between each, to make each pair flow the same, and the bleed screw is to balance flow within a pair. If the bleed screws don't have enough, then hold the throttle body up to the light with the throttle closed. You'll probably see the butterfly isn't perfectly centered because they weren't assembled very carefully. So they flow different amounts of air. You can slacken the two fixing screws and recenter the butterflies to balance them. But.... Why does the first need more air on yours? That doesn't sound right. Edited 12 hours ago by jonbill Quote Link to comment Share on other sites More sharing options...
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