no top end power

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nightmarcher
Posts: 6
Joined: Fri Jul 10, 2009 8:19 pm
Bikes: 1954 Panhead
Location: Honolulu, Hawaii

no top end power

#1

Post by nightmarcher » Fri Jul 17, 2009 9:29 pm

Hi guys I just picked up a 54 and I had a few questions. The bike wasn't idling correct so the previous owner put a bendix carb on it which fixed the idling but now the bike has no top end. First it was starting to pop and now it seems to lose power as you go up in RPMs. The previous owner was suggesting maybe something to do with the heads, possibly valve guides coming lose, because the problem is intermittent. Any suggestions would be great.



nightmarcher
Posts: 6
Joined: Fri Jul 10, 2009 8:19 pm
Bikes: 1954 Panhead
Location: Honolulu, Hawaii

Re: no top end power

#2

Post by nightmarcher » Fri Jul 17, 2009 9:39 pm

I forgot to mention, I pulled the plugs and one cylinder is sooty black and the other seems a little rich. Also the bike has solid lifters and I believe aluminum pushrods. Sorry this is my first panhead. thanks

steve_wood
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Re: no top end power

#3

Post by steve_wood » Fri Jul 17, 2009 10:20 pm

Hmmm... could be a there's more than one problem. Can you do the following tests and report the results?

- Compression test

- Remove carb and check for leaks in the intake manifold
(if you need a kit: http://www.geocities.com/mbskeam/index3.html)

- Leaving the carb off, do a leak down test. Listen in the intake manifold for leaks.

Any details on the carb? Model # and size of the jets? Adjustment on the jets (if applicable)?

steve

steinauge
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Re: no top end power

#4

Post by steinauge » Mon Jul 20, 2009 1:59 pm

Nother thing on Bendix carbs is the O ring on the main jet\main nozzle\float bowl retaining bolt(all one part). If the O ring is damaged the engine will run very poorly indeed.I sure would run a compression\leakdown and a manifold leak test first.

nightmarcher
Posts: 6
Joined: Fri Jul 10, 2009 8:19 pm
Bikes: 1954 Panhead
Location: Honolulu, Hawaii

Re: no top end power

#5

Post by nightmarcher » Mon Sep 14, 2009 1:47 pm

It turns out the front head had a broken exhaust valve spring.

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