1978 Gs400 tach drive and petcock help needed.

[Flak Jacket]

Hello,

I have an issue, I need a tach block off plate or plug in the enginer for the 1978 gs400. Anyone make one? Or is there a stock one I can buy to modify?

I also need some help with the vacuum line on the petcock. There is not a vacuum port on my carb. From what I see it should be near the idle mixture screw on the left but that port is not drilled. I need to drill the carb and add this port? Pictures and a part number or link to part would be awesome.

[Guest]

Hi mate and welcome to the forum.

I believe the later model four cylinders with the electronic tacho have a block off bolt/plug for the tacho drive, but I don't know the details. Hopefully someone can clarify on that account.

As for the fuel tap... if you don't have a vacuum port perhaps it's an aftermarket non-vacuum type? Got a photo?

[Flak Jacket]

Hi mate and welcome to the forum.

I believe the later model four cylinders with the electronic tacho have a block off bolt/plug for the tacho drive, but I don't know the details. Hopefully someone can clarify on that account.

As for the fuel tap... if you don't have a vacuum port perhaps it's an aftermarket non-vacuum type? Got a photo?

Thanks for the info. I will look at the electrical tach bikes.

Sorry I wasn't clear on the petcock. The actual fuel petcock has a vacuum port, the carbs do not have a vacuum port. Can I add one to the carb? Or should I just switch to an aftermarket petcock?

[Guest]

Thanks for the info. I will look at the electrical tach bikes.

Sorry I wasn't clear on the petcock. The actual fuel petcock has a vacuum port, the carbs do not have a vacuum port. Can I add one to the carb? Or should I just switch to an aftermarket petcock?

Ok that's a little odd... there definitely should be a port exactly where you say unless of course someone's swapped the carbs out from some other bike. I would imagine if there's no port there there'd be no easy way to make one if the carbs aren't designed for it.

I assume no fuel is flowing at the moment like this?

Sounds like an aftermarket non-vacuum type could be the go, just remember to always switch the tap off and on.

Do you have any pictures of the carbs at all? That might help...

[Flak Jacket]

I am currently turning the bike to prime to ride it. I need to get an aftermarket petcock or add the fitting to the carb. You can see both carbs are plugged in the position that the vacuum port should be.

[Guest]

Wow ok, they look like mine, but your mixture screw appears to be exposed and there's definitely no vacuum port there. You also have some sort of little bracket under the choke lever too which isn't there on mine.

Is the right carb's mixture screw exposed like that as well? I haven't seen carbs off a 400 myself so I'm not sure if they're right or not.

Hopefully someone with a 400 can chime in... but I'd suggest not drilling anything myself...

[ChicagoBob]

Suzuki GS1100S tack drive block-off should fit. It's Bike Bandit part nos. 1064353 (490253-001) for the plug and 1064362 (490260-001) for the seal (or use the seal from your existing tach drive). Less than $15. These parts are listed for the 1982 GS1100S, GS300 and others.

[Flak Jacket]

Suzuki GS1100S tack drive block-off should fit. It's Bike Bandit part nos. 1064353 (490253-001) for the plug and 1064362 (490260-001) for the seal (or use the seal from your existing tach drive). Less than $15. These parts are listed for the 1982 GS1100S, GS300 and others.

Awesome thanks. I will try that part.