PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 16, 2019 06:43PM

New here just recently bought a sweet puch maxi

Asking for Thoughts and Prayers y'all

I have a PHBG dellorto and died riding it, sounded like lost of compression or possibly not engaging the clutch so popped it open and have replaced my piston (chunck of the crown missing) new 3 foot clutch (1 of the old 2 foot pad was cracking off) so was thinking this mixture was the cause, now I think it was running fine with those issues and have narrowed it to the carb. I can pour gas into the reedblock and get it to run for a second.

I fully disassembled and cleaned out jet/atomizer 3x, Gas is getting to the bowl but when I twist throttle it doesn't look like gas is spraying. (not sure if that is what I should see on these carbs this is what I am used to seeing on a motorcycle carb) I noted there doesn't look to be an accelerator pump on these carbs so not sure what would cause a lack of gas getting from bowl to the reedblock... or curious if this may be a base setting for these carbs to get it started and tuning? Online research has been no help just tuning while its running which would be great if I could get there...

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Re: PHBG not delivering gas to the cylinder?

Overpriced Parts /
roffman
Sep 16, 2019 07:04PM

What moped, what kit, what pipe, what filter? What anything ?

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 16, 2019 08:22PM

Apologies didn't think you'd need all of that considering the diagnostics I had run...

upgrades are as follows to my knowledge, I was given limited info when I bought it but fairly certain this is all correct. they upgraded with the 64cc kit from treatland about 10 years ago

78 Puch Maxi

malossi PHBG 90 air filter E8

Polini 64cc cylinder kit

puch tecno CHROME BOSS performance pipe

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Re: PHBG not delivering gas to the cylinder?

P D /
pdcomm
Sep 16, 2019 08:47PM

Dellorto Carb tuning manual :

http://www.iwt.com.au/private/Dellorto manual.pdf

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Re: PHBG not delivering gas to the cylinder?

Dan Catalyst /
turtle_dan
Sep 16, 2019 11:31PM

Id look at the floats and valve real close.

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Re: PHBG not delivering gas to the cylinder?

P D /
pdcomm
Sep 17, 2019 09:26AM

> P D Wrote:

> -------------------------------------------------------

> Dellorto Carb tuning manual :

>

> http://www.iwt.com.au/private/Dellorto manual.pdf

Copy & paste that^ entire link as is , including the space and manual.pdf , into your address bar .

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Re: PHBG not delivering gas to the cylinder?

Don Ohio /
don45640
Sep 17, 2019 11:20AM

Probably blew a flyside crank seal. Won't pull gas into combustion chamber from carb,just air from outside.

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 17, 2019 12:22PM

> Don Ohio Wrote:

> -------------------------------------------------------

> Probably blew a flyside crank seal. Won't pull gas into combustion

> chamber from carb,just air from outside.

@don if this was the case would the motor still fire up when/if you put gas straight into the reedblock I wouldnt think so but? any possible diagnostics I can run to see if that is the issue I'm assuming pulling the electronics and looking...

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Re: PHBG not delivering gas to the cylinder?

Don Ohio /
don45640
Sep 17, 2019 12:22PM

> Brandon Hirata Wrote:

> -------------------------------------------------------

> > Don Ohio Wrote:

>

> > -------------------------------------------------------

>

> > Probably blew a flyside crank seal. Won't pull gas into combustion

>

> > chamber from carb,just air from outside.

>

> @don if this was the case would the motor still fire up when/if you put

> gas straight into the reedblock I wouldnt think so but? any possible

> diagnostics I can run to see if that is the issue I'm assuming pulling

> the electronics and looking...

It'd fire but not continue when the fumes were spent.

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 17, 2019 12:32PM

Thank you! I couldn't find this the only one I found was a dead link

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 17, 2019 12:34PM

ok so these motors need the pressure from the motor to vacuum up all that gas... I'll look into it and update.

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Re: PHBG not delivering gas to the cylinder?

Don Ohio /
don45640
Sep 17, 2019 12:35PM

Wnen a crank seal under the magneto blows, it sounds just like you killed the switch at road speed. Dead.

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 21, 2019 12:44AM

I opened it up it looks good still I would think you'd see fluid seeping out? it was relatively clean in there...

IMG_6601.JPG
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Re: PHBG not delivering gas to the cylinder?

Don Ohio /
don45640
Sep 21, 2019 12:57AM

No,the fuid is on the trans side. That seal keeps air from leaking in to combustion so it will pull thru carb.Replace the seal while yer in there. Never go by how it looks.(edited)

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 21, 2019 01:46AM

swapped, looks like same issue is persisting. No gas getting up from the bowl to the reedblock, I can pour gas directly into the carb throat and it'll start up.

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Re: PHBG not delivering gas to the cylinder?

Dirty30 Dillon /
hydra
Sep 21, 2019 10:11AM

Did you hone your cylinder, purchase the correct letter size piston and gap your rings. I bet your have bad compression

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Re: PHBG not delivering gas to the cylinder?

pat splat /
ggspeed
Sep 21, 2019 11:13PM

anytime u see oil residue( looking wet )on magneto side behind stator plate or area that means the seal is bad. theup stroke on a two stroke sucks in gas into the case/crank area. retorque head.

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Re: PHBG not delivering gas to the cylinder?

Brandon H /
skinb
Sep 22, 2019 08:26PM

So I pulled the whole top end again, because I retested and SAW some spit from a blown (brand new) base gasket. Cut a new one, retorqued and she's off. I think it was low compression from the air leak/gasket not sealing properly

break in time, Appreciate all the help everyone!(edited)

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