Intermittent Problem

[Lechy]

It's possible that you have a partially blocked pilot air jet, the jet in the carb throat on the filter side.

[emoji41]

[OhmsLaw43]

Maybe. I just had the carbs completely gone through at a very good carb guys shop this last month so I wasn’t looking at them so much.

[Lechy]

I'm just throwing ideas at you, without actually being hands on it's difficult to diagnose problems. Next time it starts acting up, shut it down, put an aerosol top under the drain nipple of the carb, open the drain and see what comes out.

[emoji41]

[OhmsLaw43]

I really appreciate the help and it actually helps having another perspective on the issue. I’ll try that on the way home from work (if it does it since I’m in SoCal and traffic doesn’t move). A buddy suggested that maybe the fuel pump relay might be getting warm and disengaging so tomorrow I might try jumpering it to see what happens. I did see a little rust in the inlet/outlet tubes on the pump so that might be a sign

[Lechy]

Jumper to the O/W on one of the coils, then you can shut the pump off with the bar kill switch in case of an emergency. I got rid of that stupid bloody relay years ago.

[emoji41]

[Herb]

Jumper to the O/W on one of the coils, then you can shut the pump off with the bar kill switch in case of an emergency. I got rid of that stupid bloody relay years ago.

[emoji41]

I would be leery of using coil power for the pump. It could cut the power to the coils during starting.

I jumpered at the relay connector on my 1400 years ago and took the relay out of the system.

[WintrSol]

Jumper to the O/W on one of the coils, then you can shut the pump off with the bar kill switch in case of an emergency. I got rid of that stupid bloody relay years ago.

[emoji41]

Do you mean, disconnect the Y/G wire at the pump connector, and replace it with a jumper from the O/W wire? Doing this would bypass the relay, and determine if it is the cause. The pump relay is internal to the pump, so it is hard to remove it to run the pump directly, but bypassing it would certainly be a valid test.

It appears that something is reducing fuel flow enough that the front carb runs out when demand is higher. A failing fuel pump relay ,or pressure switch in the pump, would be a candidate. The pressure switch turns the relay off when both carbs are full, and when the pressure falls, closing that switch again, the pump won't run until another pulse comes from the coil signal wire, so if that switch is going bad, the relay would not power the pump properly. On the early models, one could clean that switch, and keep the pump working another day; don't know if it is accessible in the newer pump design.

[OhmsLaw43]

Thanks guys. My relay is external so it would be easy to jumper. I am also thinking weak pump. My buddy replaced it before I bought the bike however it does have a little rust/deposits inside the two tubes. I can get another pump for about $65 brand new just trying to eliminate all the cheap solutions first

[WintrSol]

Your fuel pump relay is external? The wiring diagram for that model shows it inside the pump, so if yours is external, someone has modified your wiring.

OK, I looked again at the wiring diagrams, and they don't distinguish between internal and external fuel pump relays. The parts diagram shows the pump with a 2-wire connector, though, so external relay. So, you can more easily bypass the relay. But then, it shows the same drawing for the '05 S50, which just figures.

[Lechy]

The OW is constant live, coming directly from the kill switch to the coils with a branch to the CDI box. Hooking the pump to any other hot wire will enable the pump when the ignition is turned on but will only stop the pump by turning the key off. Hooking up to the OW is safer as the pump can be shut down by the kill switch on the bar controls.

[emoji41]

[OhmsLaw43]

I’ll try it though it seems funny that it would stop working at a pretty constant distance 30-35 miles the. Work again. When it did it today it sounded like the ignition was cutting out then back in. I replaced the igniter but maybe I should have gotten a better one. I’m also thinking of replacing the pulse generator however in bikebandit and ronayers they aren’t even listed

[Lechy]

Probably not your problem but I experienced an intermittent spark failure, mine was quite random, had me scratching up a bald spot. Turned out to be a broken wire at the transit plug going into the alternator cover. I replaced all 7 wires, used a 4 pin connector for the pulse wires and soldered the 3 phase (yellow) wires to the RR rather than use a connector, the phase wires tend to get a bit hot and melt the connector.
Re-check the hose from the tank to the pump with the pump in place , it is easy to kink it just before it enters the pump when bolting the pump back.

[emoji41]

[WintrSol]

I’ll try it though it seems funny that it would stop working at a pretty constant distance 30-35 miles the. Work again. When it did it today it sounded like the ignition was cutting out then back in. I replaced the igniter but maybe I should have gotten a better one. I’m also thinking of replacing the pulse generator however in bikebandit and ronayers they aren’t even listed

The part number is 32160-38A10, listed here: https://www.partsoutlaw.com/oemparts/a/ ... el-n-p-r-s
Note that it is shown as not available, so finding one could be a problem. Other parts diagrams show it as a part of the stator assembly, not sold separately.

[OhmsLaw43]

Yeah everywhere I’ve looked says it isn’t available. It’s either over $300 for OEM or a risky $65 Chinese stator with pulser. I might go the cheap route as the bike cost me $500. Another insight from this morning. When it started acting up it sounded like I was turning the key off/on with the gas on. Seems to still only be the front cylinder though and since the 95 only has one pulse generator winding it doesn’t make sense

[WintrSol]

Maybe that means it is finally going to fail hard enough to find. [emoji106]

[OhmsLaw43]

Gawd I hope so. This has sucked on so many levels

[OhmsLaw43]

So a little update on my issue. Replaced the stator and pulse generator since applying heat to the pulse generator caused the resistance to rise in it. Didn’t fix the original issue. Ordered and replaced the fuel pump since I can’t think of anything else that would cause it to act like the front carb is out of gas then the rear goes dead. Put heat shielding on the fuel lines just in case it was a vapor lock problem. NOPE!!! Still doing the same thing. Would ignition switch cause this ? I’ve tried everything else

[WintrSol]

You said you tested the fuel pump; did you test how quickly it would empty the fuel tank into another tank? If the tank is full, it should take less than 20 minutes to empty it, including reserve. Do this with the cap on, of course.

[hillsy]

You said you tested the fuel pump; did you test how quickly it would empty the fuel tank into another tank? If the tank is full, it should take less than 20 minutes to empty it, including reserve. Do this with the cap on, of course.

Yes - do this.

You may have a partially blocked fuel tap or some other thing you weren't expecting that is impeding the fuel delivery.

[OhmsLaw43]

I’m actually going to put a pressure gauge between the carbs to see what’s going on. Going to machine a straight tap instead of a petcock to see what that does too. My friend thinks there is a proportioning valve in the rear carb so we are going to check that too