94 Speedster twin 657.
So I have gone through my second set of carbs, and am trying to leak test them. I have cleaned all surfaces, and components on MAG & PTO. When I do my pop off for them, I have done it with the carbs closed, and I am getting about 30psi on the PTO and 10psi on the MAG! I noticed that the MAG side isn't "popping" like it should, and it's probably related to the spring, causing the needle/seat to leak prior to breaking free, but both springs match, and the arm assembly is aligned properly. I checked all gaskets/ seals for cracks or tears with out any and all brass for wear or marring. I am confident that everything is clean.
I am wondering if I should do my test with the tester on the back side of the N/S like the thread by qstorm, or do I keep it closed like the Mikuni manual says and use the input/output fittings? I figure doing it when sealed, introduces the possibility of a bad diaphram skewing the results. This may allow me to rule out certain issues, but is it a truly correct pop off test?
If I do find that the needle and seat are fine, can any one tell me what the max difference should be between pop off pressure on the two carbs?
Lastly, anyone know what fitting was could be used through the back of the needle seat for the test?(trying to stuff 1/4 hose into that hole could prove problematic for me)
Sorry for all the questions. I did actually try to find the best answers through the search, but with little luck on these.
Thanks guys!
So I have gone through my second set of carbs, and am trying to leak test them. I have cleaned all surfaces, and components on MAG & PTO. When I do my pop off for them, I have done it with the carbs closed, and I am getting about 30psi on the PTO and 10psi on the MAG! I noticed that the MAG side isn't "popping" like it should, and it's probably related to the spring, causing the needle/seat to leak prior to breaking free, but both springs match, and the arm assembly is aligned properly. I checked all gaskets/ seals for cracks or tears with out any and all brass for wear or marring. I am confident that everything is clean.
I am wondering if I should do my test with the tester on the back side of the N/S like the thread by qstorm, or do I keep it closed like the Mikuni manual says and use the input/output fittings? I figure doing it when sealed, introduces the possibility of a bad diaphram skewing the results. This may allow me to rule out certain issues, but is it a truly correct pop off test?
If I do find that the needle and seat are fine, can any one tell me what the max difference should be between pop off pressure on the two carbs?
Lastly, anyone know what fitting was could be used through the back of the needle seat for the test?(trying to stuff 1/4 hose into that hole could prove problematic for me)
Sorry for all the questions. I did actually try to find the best answers through the search, but with little luck on these.
Thanks guys!
