So, I've been emailing with a guy from Pingel and he doesn't quite understand how our fuel system works. And frankly, I'm no expert either.
My goal is to consolidate both fuel petcocks (the one under the tank, and the one on the side) into one, user-friendly system. The one he is suggesting has "ON/OFF/RES" capability and will mount under the tank. If that is the case, how do I route fuel to the PRIME tube that feeds the bottom of the carb bowls? Can I do without the RES setting and simply have "ON/OFF/PRIME."
Anyone who has replaced the stock petcocks, please chime in on the best (and least expensive) way to do this.
Thanks,
Brian
i have the pingle one, it has ON/OFF/RES
im happy with it, im not sure what the prime is all about as ive never used it.
There is no "prime tube". Are you referring to the vaccuum line that runs from the petcock to the right side of the left carb? Its purpose is to stop the flow of fuel unless the engine is running. Moving the petcock to the PRIME position bypasses this and always lets fuel flow into the carbs.
If your new petcock has an OFF and no PRIME position, you won't need the vaccuum line. Just cap the connector on the carb.
Prime by-passes the vacuum part of the petcock.
Using a Pingel valve eliminates the vacuum connection from the carb, which needs to be capped. The ON position will act like PRIME. Remember that you will need to manually turn off the tank as the float needles will be the only valve controlling the flow of gas to the carbs after the bike is turned off.
There was a post with the info from Pingel.
here it is: http://gstwins.com/gsboard/index.php?topic=17129.0
dangit dgyver beat me to it....oh well i guess i'll just go play with my petcock now :laugh: :laugh: :laugh:
Quote from: natedawg120 on August 02, 2006, 10:31:21 AM
dangit dgyver beat me to it....oh well i guess i'll just go play with my petcock now :laugh: :laugh: :laugh:
Let's hope no one asks for pictures
With an aftermarket petcock you don't need Pri. The stock valve has a vacuum-operated diaphragm that prevents fuel from flowing unless the engine is running. The Pri setting bypasses this diaphragm and allows fuel into the carbs whether the engine is running or not. Since aftermarket petcocks do not have the vacuum system there is no reason for a Pri setting.
There are three good reasons why you shouldn't use a Pingel petcock mounted to the tank:
1. You have to buy an expensive adapter plate since they usually come with a threaded mount.
2. The frame blocks access to the underside of the tank so there's no easy way to switch the valve on/off. You could rig up some kind of linkage I guess but it would still be a pain in the ass to get to.
3. They're ridiculously overpriced.
The much better option is to leave your tank petcock in place and replace the frame petcock with a simple on/off valve like one from a dirtbike. I have a Honda 450 petcock on mine now and I'm working on a writeup to illustrate the process.
-M
Pictures, you say? Behold my super-oversimplified MS Paint awesomeness!
(http://www2.newnanutilities.org/~ewhitley1/bikes/fuel.jpg)
lol,
the pingle is a biatch to get to, as far as on/off goes, but i dont have any other complaints than that, and i have small fingers that reaching is not a problem :thumb:
i undeerstand now! the Clymer's manual is just not clear as to how this thing works. THANK YOU.
is there any way to disassemble the OEM petcock on the side of the bike and maybe check to see if that valve is sticking? does it require regular service? if i can repair it for free, i'd be vewy happy.
one last question...when i leave the bike on PRI, fuel just keeps flowing out of the carbs and onto the floor. is this right? seems extremely dangerous to me. is that a feature of a gravity-fed system?
Quote from: baco99 on August 02, 2006, 11:51:58 AM
is there any way to disassemble the OEM petcock on the side of the bike and maybe check to see if that valve is sticking?
Sure there is. Disassemble it. And then see the if the valve is sticking. :)
Seriously, thought, it prety much just unscrews. If you diaphram is broken, that will cause it not work. I found you can test it just be taking it off and sucking on/blowing through various hoses.
Quote
one last question...when i leave the bike on PRI, fuel just keeps flowing out of the carbs and onto the floor. is this right? seems extremely dangerous to me. is that a feature of a gravity-fed system?
It's kind of a feature. If you leave a gravity fed system on, it might leak, but probably shouldn't. Leaking is usually a sign of something wrong (bad gasket, bad float valve).
when you take the top caps off the carbs, i'm missing the small O-ring on the right side. would that do it? :mad:
(thanks for all your help, i'm not used to a system like this. i'm used to a car's fuel system which is almost always pump fed, whether solid state or mechanical...and without "RES" and "PRI." usually i just put the fuel in the float chamber and watch the vacuum pick up the fuel and spray it into the venturi through the needles. it's hard to tell if it's working with this set up. and the Mikunis seem to really change character whether the air intake is on or off the bike.)
also, the left float valve was sticking when i took the air cleaner off. right one bobbed up and down freely. i think the spring at the top was stuck or wasn't installed properly.
lol, you sound just like me...
mine poured gas out cuz i accedently swapped the fuel line...
Quote from: baco99 on August 02, 2006, 11:51:58 AM
one last question...when i leave the bike on PRI, fuel just keeps flowing out of the carbs and onto the floor. is this right? seems extremely dangerous to me. is that a feature of a gravity-fed system?
No, one or both of the float valves in your carbs aren't sealing properly. The float valves are located at the bottom of the carb; drain and remove the float bowls for access. Remove and clean the floats, bowls, float needle and seat. If the fuel level does not stabilize with the petcock set to PRI you should replace both float valves. It's the piece in the plastic bag in this pic:
(http://i13.ebayimg.com/03/i/03/0a/3d/8b_1_b.JPG)
thanks. looks like i'm ripping the carbs apart this weekend.
been there done that recently, good luck with it :)
oh, and dont forget the pics :thumb: