Phbh28 advice please

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hendy
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Sun Aug 30, 2020 2:16 pm

Folks. Advice on which way to go from here please?

Stage 4 or 5 (whatever that means) piston ported 175 cast iron.
Phbh28 with breathe sweet filter
Gori 48mm (not the gp50 type)

Currently have

50 pilot
40 slide
Av264
X13 on top clip (leanest)
112 main.

Thanks

Daggs
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Sun Aug 30, 2020 5:35 pm

What's the problem?

hendy
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Mon Aug 31, 2020 7:16 am

It feels boggy at wot. So I think I should go leaner on main. But I'm slightly worried about going too lean. Does 112 seem on the large side?

Daggs
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Mon Aug 31, 2020 10:35 am

I don't understand what "wot" is............

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drunkmunkey6969
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Mon Aug 31, 2020 12:51 pm

Daggs wrote:
Mon Aug 31, 2020 10:35 am
I don't understand what "wot" is............
Wide Open Throttle...

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drunkmunkey6969
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Mon Aug 31, 2020 12:56 pm

hendy wrote:
Sun Aug 30, 2020 2:16 pm
Folks. Advice on which way to go from here please?

Stage 4 or 5 (whatever that means) piston ported 175 cast iron.
Phbh28 with breathe sweet filter
Gori 48mm (not the gp50 type)

Currently have

50 pilot
40 slide
Av264
X13 on top clip (leanest)
112 main.

Thanks
I'm not a fan of top clip settings, at least try to get a half-clip spacer in there to take it to 1.5 clip setting. I'd also suggest you set pilot to 52, keep everything else the same and do plug chops to asses. Also, have you done a fuel flow check? Needs to be 1 pint per minute. Lastly, make sure the air filter is clean.. then try a brief road test/plug chop at WOT to see what difference having the filter on/off makes, this should give clues to suggest which direction you should go in...

hendy
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Tue Sep 01, 2020 8:05 am

drunkmunkey6969 wrote:
Mon Aug 31, 2020 12:56 pm
hendy wrote:
Sun Aug 30, 2020 2:16 pm
Folks. Advice on which way to go from here please?

Stage 4 or 5 (whatever that means) piston ported 175 cast iron.
Phbh28 with breathe sweet filter
Gori 48mm (not the gp50 type)

Currently have

50 pilot
40 slide
Av264
X13 on top clip (leanest)
112 main.

Thanks
I'm not a fan of top clip settings, at least try to get a half-clip spacer in there to take it to 1.5 clip setting. I'd also suggest you set pilot to 52, keep everything else the same and do plug chops to asses. Also, have you done a fuel flow check? Needs to be 1 pint per minute. Lastly, make sure the air filter is clean.. then try a brief road test/plug chop at WOT to see what difference having the filter on/off makes, this should give clues to suggest which direction you should go in...
Thanks Dan. I did try a shim on needle, but it didn't like it. I'm thinking of using x7 but your words "deadly combination" are putting me off :lol:

I'm sure the breathe sweet is a really free flowing filter and is clean.

Probably best to leave as is until I (hopefully) get it on mick abbey's dyno later in the week. Then I'll try 52 pilot and x7.

hendy
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Tue Sep 01, 2020 8:08 am

Here's the plug after 10 minutes of spirited riding. Not a proper plug chop but does indicate that it's slightly too rich to me.Image

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drunkmunkey6969
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Tue Sep 01, 2020 11:21 am

hendy wrote:
Tue Sep 01, 2020 8:08 am
Here's the plug after 10 minutes of spirited riding. Not a proper plug chop but does indicate that it's slightly too rich to me.
I would agree... the question is, at which RPM range and throttle opening position? :D

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drunkmunkey6969
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Tue Sep 01, 2020 11:31 am

hendy wrote:
Tue Sep 01, 2020 8:05 am
Thanks Dan. I did try a shim on needle, but it didn't like it. I'm thinking of using x7 but your words "deadly combination" are putting me off :lol:
I can't remember which video I expanded on that in, but I think I inserted the caveat of 'deadly combination...in anything other than a standard or low-performance engine running a clubman and a filter' - or at least words to that effect. It's in one of the 3 jetting videos.

So, basically, your engine is a) small CC at only 175, b) running a clubman, c) running an air filter, d) running the 28mm instead of the larger 30mm... so there is every chance an AV264 and X7 combo will work safely in those parameters. I'd just suggest that you 'pad out' everything around it first, to provide a safety cushion whilst you test and adjust... so make sure your mix screw is correct, pilot/main/clip are all rich.... then pop in the AV264/X7 combo and 'work backward'. Essentially, always go too rich first, and lean off carefully to suit.

With the AV264/X7 in place, you'll probably be able to go to either 2nd or 2.5 clip on the needle, a 52 pilot, and certainly keep the main you are running, or maybe even a slightly larger if it will take it? Don't forget to do a fuel flow test and pop in a new plug before the dyno, let us know how you get on. :D

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