Wed May 26, 2021 3:35 am

Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
 
Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
Wed May 26, 2021 3:35 am linkquote
I have a 79 P125x that I rebuilt the engine over the winter and installed a Malossi 177 kit along with a SIP Road 2. The carb is a dellorto 20/20. I am working on the jetting but the initial problem is that I have to screw in the idle speed screw in all the way in just to keep the scooter running. With the idle speed screw turned all the way, at this setting, the scooter idles fine and is at the speed it should be but the idle adjustment does not do anything to effect the running of the scooter at idle. You can screw it all the way in or all the way out and it does not make any difference to the idle.

My question is because of the larger cylinder and pipe is it common that the slide has to be this far open to keep it running and is this telling me that maybe the carb is not big enough or something? Should this set up have the 24/24 carb or something? I have rebuilt the carb and tore it down twice and cleaned it with no change.

Last edited by msprygada on Wed May 26, 2021 8:56 am; edited 1 time in total
Wed May 26, 2021 5:55 am

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
Wed May 26, 2021 5:55 am linkquote
20/20 should feed it just fine. What idle jet and slide is installed? How many turns out is your air corrector?
Wed May 26, 2021 8:35 am

Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
 
Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
Wed May 26, 2021 8:35 am linkquote
The slide is the one that came in the carb. The idle jet is a 52-140 and the main stack is 160-BE4-115.

Not sure what you mean about how many turns is the air corrector? I thought that is the 160 part of the main stack was the air corrector.

The idle mixture screw (back of the carb) I can turn in all the way in or all the way out and it does not effect the idle what so ever but I started with 1.5 turns out as the default.

The idle speed screw (long top screw) has to be turned in all the way in just to maintain an idle that keeps the scooter running which is about where you would want it. Backing it out from fully turned in and the scooter will stall.
Wed May 26, 2021 9:10 am

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
Wed May 26, 2021 9:10 am linkquote
Whoops. Yea typo on my end. I meant idle mixture screw. Nothing screams out of place. Throw the 55/160 idle jet back in and see if that helps.

Do you have a spare carb you can throw on for giggles? What's your engine compression? Good strong spark? Got the stuff for a leak down test?
Wed May 26, 2021 10:52 am

Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
 
Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
Wed May 26, 2021 10:52 am linkquote
A little back story. I bought the scooter last fall with the head not attached. The guy had burned down the piston slightly (not really much damage at all). So I rebuilt the engine with new bearings and seals and put a Malossi 177 kit on it with the SIP 2 pipe. He did have a replacement spaco 20/20 carb and I did try that but the damn thing leaks from somewhere under the carb. I have to get a rebuild kit to see what is going on with it as I see nothing obvious with it.

This P had points and I had issues getting it to spark and after not being able to fix it, I just got tired and put in factory electronic ignition and it works great now.

I have not checked engine compression and I do not have (or I don't think I have) the equipment for a leak down test as I don't know what that is for.

With the current set up, it starts up first kick cold or warm. You can tell how strong the spark is buy the way it runs. I have tried various jet settings but I can't get it to work great across all range. But the ranges that it does work good on, it pulls hard and sounds really good and strong.
Wed May 26, 2021 12:14 pm

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
Wed May 26, 2021 12:14 pm linkquote
As far as the spare carb goes, its probably leaking from the bowl overflow tube (right below the banjo) or weeping from something in the float assembly. Is the needle good or rotted out? Swap the guts from carb 1 to carb 2 till you get your rebuild kit. Jets look close enough.

Do you have the right air filter installed? Gaskets below the air box and one below the carb? Air box securing screw down tight?

As far as the electronics. Did you time it for 18ish degrees? Not your culprit but just something you should do.

Nothings sadly screaming out at me as an aha!
Wed May 26, 2021 12:54 pm

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: 26 Sep 2013
Posts: 6010
Location: So Cal
 
bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: 26 Sep 2013
Posts: 6010
Location: So Cal
Wed May 26, 2021 12:54 pm linkquote
Quote:
With the idle speed screw turned all the way, at this setting, the scooter idles fine and is at the speed it should be but the idle adjustment does not do anything to effect the running of the scooter at idle. You can screw it all the way in or all the way out and it does not make any difference to the idle.
I think you need a leaner idle jet.
Wed May 26, 2021 1:42 pm

Hooked
2005 Stellalossi 177 Fe
Joined: 14 Jun 2020
Posts: 137
Location: MA
 
Hooked
2005 Stellalossi 177 Fe
Joined: 14 Jun 2020
Posts: 137
Location: MA
Wed May 26, 2021 1:42 pm linkquote
I am suspicious that something is blocking the idle jet circuit. That would tend to explain why the engine only runs with the idle speed screw all the way in, and also why adjusting the mixture screw does nothing. I would remove the carb and give it a thorough cleaning with carb cleaner and compressed air, paying special attention to the idle jet circuit.

The Malossi 177 kit will run fine with a 20-20. I found the 52/140 idle jet and the BE4 mixer tube that come with the kit were necessary for it to run right at mid-throttle. The BE4 is a mixed blessing, though, because it also makes the main stack comparatively rich at WOT. On my Stella, if I compensate for the BE4 by running an AC160, I need an MJ120. The Stella has a reed valve. With a rotary valve, you might not need to go that big.
Wed May 26, 2021 1:59 pm

Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
 
Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
Wed May 26, 2021 1:59 pm linkquote
MJRally wrote:
As far as the spare carb goes, its probably leaking from the bowl overflow tube (right below the banjo) or weeping from something in the float assembly. Is the needle good or rotted out? Swap the guts from carb 1 to carb 2 till you get your rebuild kit. Jets look close enough.

Do you have the right air filter installed? Gaskets below the air box and one below the carb? Air box securing screw down tight?

As far as the electronics. Did you time it for 18ish degrees? Not your culprit but just something you should do.

Nothings sadly screaming out at me as an aha!
Air filter is installed, gaskets below both air box and carb, and timing at 18 degrees (which is factory timing)
Wed May 26, 2021 3:29 pm

Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 3276
Location: Staten Island, NY
 
Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 3276
Location: Staten Island, NY
Wed May 26, 2021 3:29 pm linkquote
Kowalski wrote:
The Malossi 177 kit will run fine with a 20-20. I found the 52/140 idle jet and the BE4 mixer tube that come with the kit were necessary for it to run right at mid-throttle.
Agreed, the malossi 177 kit comes with it and they suggest it for the kit so even a PNP kit I'd imagine needs the 52/140. Gotta adjust everything else to work with it which may throw you off from standard jetting setups..
Wed May 26, 2021 4:20 pm

Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
 
Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
Wed May 26, 2021 4:20 pm linkquote
Found the issue with the Spaco carb leak. The large banjo gasket was missing. not,sure how that happened but I Installed a new gasket and the carb does not leak now.

With the Spaco carb I am able to get the the idle down on to the idle jet and can adjust the idle mixture and it changes the idle speed so I am good there.

Now just need to ride it and figure out the jetting.
Wed May 26, 2021 4:54 pm

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
Wed May 26, 2021 4:54 pm linkquote
Nice sleuthing!
Wed May 26, 2021 5:11 pm

Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
 
Addicted
1965 Sears Allstate, 2013 GTS 300 Super i.e.
Joined: 24 Jul 2012
Posts: 620
Location: Bay City, MI
Wed May 26, 2021 5:11 pm linkquote
I seen a thread where they talk about carb drilling. What is getting drilled?
Wed May 26, 2021 5:25 pm

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4022
Location: Oceanside, CA
Wed May 26, 2021 5:25 pm linkquote
The hole in the float bowl that feeds the main jet. That's a restriction for your thirstier kits. Search YouTube for a few how to videos
Wed May 26, 2021 6:21 pm

Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 193
Location: Los Angeles
 
Hooked
1959 Allstate w P125x Engine
Joined: 29 Nov 2020
Posts: 193
Location: Los Angeles
Wed May 26, 2021 6:21 pm linkquote
SoCalGuy wrote:
I think you need a leaner idle jet.
Yep.
But wouldn't it get wonky or die all the way out?
Blind wild guess: Threads are stripped on the idle mixture screw, making for a false "all the way in." Or an incorrect spring on it, doing the same.
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