Silver Century plus not revving up

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Charles uk
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Re: Silver Century plus not revving up

Postby Charles uk » Sun Sep 17, 2017 4:03 pm

I've had 2 over the years that came to me for thread repair inserts, I machined, tapped & fixed the inserts only to find that when I went to machine the protruding insert & corroded throttle slide base, the base of the throttle slide body had been raised so the banjo bolt could reach the last of the threads, one I managed to repair with Loctite Hysol 615 epoxy & one was scrap, a lot of work to throw something away.

Oyster anyone who works on his own planes carb in a location that is so well blessed with mountainous, tree covered emergency landing sites must have a fairly good grasp of what he's doing.
Make it idiot proof and someone will make a better idiot.

rstumpy
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Re: Silver Century plus not revving up

Postby rstumpy » Sun Sep 17, 2017 11:02 pm

Thank you for the vote of confidence Charles....I do crash better than anyone I know... :shock:

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Nudge
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Re: Silver Century plus not revving up

Postby Nudge » Mon Sep 18, 2017 10:16 am

I do crash better than anyone I know... :shock:


:lol: :lol: :lol: :lol: :lol:
"THE KING OF BLING"!
Is it better to over think, than not think at all?

rstumpy
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Re: Silver Century plus not revving up

Postby rstumpy » Thu Sep 21, 2017 1:14 am

Honest fellows...I really am a fairly competent wrench and archaic designs have generally been my forte. I used to mess with gulls a great deal and this is the first time one has resisted my soothing efforts.
To reiterate...clearly it must be too much flow, pointing to the needle/float. That being said, with the long-range tank half full and the fuel tap on all the way, the carb isn't overflowing a bit (engine not running). Seems to me if the float/needle weren't shutting off the fuel it'd be dribbling out,correct? Only thing I can come up with is that perhaps vibration while running is preventing the flow from being shut-off/reduced, but that seems unlikely.
Have it apart again, here's a couple of pics. The darn thing shows no evidence of being cobbled-up or even rough use. As you can see, threads, etc look good. I apply a very small amount of "EZ Turn" fuel resistant lubricant to the threads as well. It's kind of an old-school slightly waxy grease that seals and protects threads, use it in aviation, especially the old stuff.
Going to reassemble without the float shim I made so it's again configured as designed.

Since I think everyone has graciously offered just about every possible solution, if it doesn't shape up this time I will just run it with the tap nearly shut until the spare carb from Martin arrives for further testing. Although this needle seems to be ok, reckon I'll order a new one to see if that makes a difference as suggested as well.

At this point I shall also follow another suggestion made by Charles...having become friends with a local priest who fishes the same section of river, my plan involves a few Hail Marys or some such thing over this carb from this seasoned professional before installation. It will probably require a side of salmon that just came out of my smoker as an offering, but small price to pay...
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Charles uk
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Re: Silver Century plus not revving up

Postby Charles uk » Thu Sep 21, 2017 8:35 am

How many banjo bolt fibre washers can I see in your picture?

1 above & 1 below, float chamber banjo.

Carb looks perfect!

Can you measure the thickness of your fibre washer? (Seagull ones are normally red).
Make it idiot proof and someone will make a better idiot.

headdownarseup
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Re: Silver Century plus not revving up

Postby headdownarseup » Thu Sep 21, 2017 6:32 pm

I see 2 BLACK washers, 1 above and 1 below at the banjo bolt. (they're not rubber are they?)
I concur that seagull ones are normally red in colour, but.....

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Charles uk
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Re: Silver Century plus not revving up

Postby Charles uk » Thu Sep 21, 2017 6:53 pm

It's the thickness that's important Jon, as the level in the float chamber is exactly the same on the jet, raise that level & the venturi effect from the passing airflow over the emulsion tube, portion of the power jet will suck more fuel or less if you lower it!

Even you, the resident carb expert will agree that carb looks to be in very nice condition!
Make it idiot proof and someone will make a better idiot.

rstumpy
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Re: Silver Century plus not revving up

Postby rstumpy » Thu Sep 21, 2017 10:00 pm

There's two...in the picture one is still on the banjo bolt.
Both black washers on the banjo bolt are fibre, measure .034" and .036" thick and are of the proper id and od.
Additionally, there's a red fibre washer under the locknut on the bottom of the float chamber that measures .032" in thickness.

Cranky1
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Re: Silver Century plus not revving up

Postby Cranky1 » Mon Oct 15, 2018 4:18 pm

I have been following this thread closely, w a similar problem. Was this ever resolved?


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