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Topic author
NY John T
- Posts: 346
- Joined: Wed Nov 25, 2020 12:45 pm
- First Name: John
- Last Name: Killelea
- * REQUIRED* Type and Year of Model Ts owned: 1926 Touring, 1927 Tudor, 1925 Touring
- Location: Northport NY
Post
by NY John T » Sat Jan 16, 2021 1:07 pm
Hi all,
Looking at my Holley NH that I'm restoring, I noticed that the 2 drilled passages at the throttle plate are both showing while the throttle is closed (see pic). Is this normal? Should they both be exposed when the throttle is closed or should the throttle cover the inner one? Thanks.
John
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DanTreace
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- * REQUIRED* Type and Year of Model Ts owned: '23 cutoff, '25 touring, '27 touring
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Post
by DanTreace » Sat Jan 16, 2021 2:10 pm
Normal, and important to be in working order.
Holes are noted are for fast idle and slow engine speed D and E.
The best way is always the simplest. The attics of the world are cluttered up with complicated failures. Henry Ford
Don’t find fault, find a remedy; anybody can complain. Henry Ford
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Ron Patterson
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by Ron Patterson » Sat Jan 16, 2021 2:17 pm
This may help?
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Attachments
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StanHowe
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by StanHowe » Sat Jan 16, 2021 2:36 pm
The purists hate me for this but when I was rebuilding NH's I found that drilling out the brass plugs in the body and cleaning the passages behind them was very important. Just be careful not to drill the holes oversize when you are cleaning them.
The easy way to seal the plugs back up is to tap them 8-32 and put a little Allen head set screw in each hole. As I said, purists will scream that you should make tapered brass plugs, pound them in and cut them off and dress them to surface.
OK, whatever works for you. The Allen head set screws work for me.
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Steve Jelf
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Post
by Steve Jelf » Sat Jan 16, 2021 2:42 pm
Here's a somewhat better copy of the service bulletin drawing.
It shows one hole (E) inside the closed throttle and one outside (D), so your situation is not normal according to the drawing.
Here's the complete explanation from the service bulletin:
The article has more about the rest of the NH.
The inevitable often happens.
1915 Runabout
1923 Touring
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Bill Coyle
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Post
by Bill Coyle » Sat Jan 16, 2021 3:19 pm
John,
In your picture, for some reason the throttle butterfly is not closed all the way, you can see a small gap between the edge of the butterfly and the bore. It may be caused by either your idle adjustment screw or the butterfly isn't aligned properly. But the answer to your question is yes, when it is closed only one should be visible.
Bill
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Scott_Conger
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Post
by Scott_Conger » Sat Jan 16, 2021 3:34 pm
When the idle adjustment screw is adjusted for this opening, it is usually due to the idle passage being either restricted or blocked. If the carb must be adjusted to run at idle as in the picture. then this is the case
Scott Conger
Tyranny under the guise of law is still Tyranny
NH Full Flow Float Valves
Obsolete carburetor parts manufactured
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Bill Coyle
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Post
by Bill Coyle » Sat Jan 16, 2021 3:39 pm
Showing with butterfly closed tight, only the one passage is exposed.
Showing slightly open like in your picture
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Topic author
NY John T
- Posts: 346
- Joined: Wed Nov 25, 2020 12:45 pm
- First Name: John
- Last Name: Killelea
- * REQUIRED* Type and Year of Model Ts owned: 1926 Touring, 1927 Tudor, 1925 Touring
- Location: Northport NY
Post
by NY John T » Sat Jan 16, 2021 4:12 pm
Thank you so much Bill,
That hits it on the head. The adjusting screw was in too far. When I backed it out, the butterfly closed completely. Problem solved.
Thanks,
John
