1983 gs450l carb question ?

[BUSARIDER]

I bought a GS450L with 5,xxx miles on it . Been stored since 1989. Carbs were stuck with varnish. I got them spotless except the pitting on the outside. I did the manly job of cleaning and re-installing them. Got the boots on ( yay me ) !!! Bike will hit and Idle for a second then die ?> It has the vacuum activated petcock. I noticed if I puff a little air in the fuel line ( very little air ) the bike ran better. is this because the vacuum activated petcock is pressurized and it pushes fuel into the carburetors ever so lightly ? I do not have an IV set up so I had about a 6 foot piece of fuel line with fuel in it to use as a IV setup. It does not work well off of gravity . SO I figured it was because the fuel system is pressurized lightly by the vacuum petcock. ?

ANY IDEAS >>?? It sounded great when running

also ... any ideas where to get an oem air filter from ?

Thanks guys you all have been a big help so far with my junkster $75.00 bike !!!

[mmain1]

The petcock is just a vacuum operated valve. In a properly working petcock the vacuum and fuel system are completely isolated, so no it does not pressurize anything. Fuel flows to the carbs by gravity alone.

Although you said you cleaned the carbs, it sounds like your float needle is stuck closed. Or the fuel/air mixture is just so far off that the second or two of running/idle is just a lucky occurrence and then it ultimately dies.

Someone with more experience than me will be along shorty to answer this I'm sure!

[tom203]

Follow the link to Basscliff's site for info overload. If you didn't dip carbs for 24 hours, it's unlikely you got all the varnish/gunk out- these carbs have tiny passages. As such, getting it to idle nicely will be challenging.Your petcock is likely clogged or damaged - how does inside of your gas tank look?

[BUSARIDER]

I got the bike to idle very well 1100 or so rpm's. Engine sounds great. It revs good to about 3,500 - 4,000 rpm's then it bogs badly and dies. Then it will start back up and idle well again and take gas well up until the above mentioned rpm ranges. Any idea's ? If it were a single carb I would say it was a diaphram issue , but being as it's both carbs you guys think it's an air leak problem ? Or ???

[tom203]

So you are currently using a tubing IV (?) setup to feed gas and not the petcock/tank ? Since you don't have a air filter yet, can you peek at carb diaphram/pistons and see if they rise as rpm goes up? might be too rich as revs go up-if it was too lean, I'd think it would backfire as it died out.

[BUSARIDER]

The bike would not run on an iv setup. It runs much better with the petcock and vacuum hooked up. I think it needed the pressure to feed the gas to the carburetors. It idles well but still dies at about 3,500 rpm's. I think I will re-pull the carburetors today and check them again. I need air-box to carburetor boots. I don't think mine will withstand another removal and install. Any idea on where to get them from ?

Thanks In Advance ... Stephen

[tom203]

Make sure your gas tank is reasonably rust free, or you will become adapt at carb removal/cleaning in no time.
This Basscliff link has lots of good info including where to buy stuff

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

[BUSARIDER]

Fuel tank and intake boots

I cleaned the fuel tank with WHITE DISTILLED VINEGAR as I do all of my steel tanks. The tank is spotless ... right after cleaning I filled it with fuel to keep it from flash rusting. Then I flushed it with the fuel in the tank and used new fuel.

I just ordered new intake boots from my Suzuki dealership = $26.00

I think I know what my problem is . When I soaked and cleaned the carburetors I didn't clean the Holes in the float bowls. I was told it has something to do with re-circulating unburned fuel ? So I was thinking this may be my problem with why it idles good but then floods out and dies at about 3,500 rpm's ?

going out to the shop now to yank them off the bike again ... I do know that part is still obstructed due to the fact I didn't clean it .

[tom203]

This "re-circulating unburned fuel " is new to me, but yes, there are tiny passages- that's why the 24 hr dip is stressed. You might get lucky, since there was no ethanol in gas back in 1989, as I recall. Your tank sounds good. This Basscliff link might be helpful

http://members.dslextreme.com/users/cbsaunders/gs/gs450_carb_cleaning_guide.pdf

[BUSARIDER]

Thanks for the manuals ... My carbs are completely different inside that those are. My bowls are just open bowls and the body of the carburetor is where the business takes place on the carburetors .

[tom203]

Thanks for the manuals ... My carbs are completely different inside that those are. My bowls are just open bowls and the body of the carburetor is where the business takes place on the carburetors .

I like learning new stuff, so what do your carbs look like inside? I'm having trouble visualizing carbs with "open bowls" doing any business related to metered fuel delivery.

[pete]

Yes, you have the '83 model... completely different carbs than the 80 - 82 models unfortunately and FC's guide only covers them.

I believe on the newer ones all the jets and circuits etc. are in the carb body, and the float bowl really is just a float bowl... I haven't seen them myself though so pic's would be great

Also, have you verified your ignition is advancing? And is there a way for the tank to vent? I'm wondering if your fuel cap vent is blocked is it choking off the flow of fuel? And if there was rust in the tank initially, did you clean the filter on the fuel tap?

[BUSARIDER]

1983 gs450l carburetors

Gonna try and get the carburetors off today. I will post a few pictures of the carburetors. The bowls and the bodies.

Thanks Again .... Stephen

[BUSARIDER]

1983 suzuki gs450l carburetor pictures

Here are the pictures of the float bowls and the carburetor bodies.

As I said the bowls are completely empty. The bodies hold the Low speed circuit and the main jet. The low speed side is shown without the rubber plugs installed. If you look at the float bowls there is a hole in the lip of the bowl and a hole that sits kinda to the side almost in the bottom. Those two holes are the 2 that I did not clean out. This is the circuit I was told re-circulates the unburned fuel ? I put some pb Blaster in them and let them sit and took a piece of wire and about 20 minutes later they were un-clogged. All jets are clean, no trash anywhere in the carburetors. Diaphrams are good no holes, good springs, floats set at the right height.

Going to put her back together ( AGAIN ) and hope for some throttle this time instead of just a good idle and about 3,000 rpm's worth of fun.

Thank You For All Y'all help ... Stephen

[BUSARIDER]

carburetor bodies

here are the carburetor bodies