intake leak

[Guest]

got my '85 gs700e running with new o-rings and a rebuild according to bikecliffs website. it idles erratically though, i synced it using feeler gauges and research says it could be an intake leak. i see you should use carb cleaner but isn't that risky to spray it near (or on) a running engine? i replaced the o-rings on the carb boots so i'm not sure where the leak can come from. or could it still be a sync issue?

[Dave8338]

Could be a sync issue, could be air/fuel issue.
Even though you used feeler gauges which will set the slides to the correct height, they can not measure the actual pull into the cylinder, of the air fuel mix. In order to do that, a good vacuum sync needs to be done. In order for the vacuum sync to be accurate, you need to have the valves adjusted. Have you done that yet?

[BassCliff]

Hi,

Is the airbox properly installed and air tight? The airbox should only draw air through the snorkel on the back. Did you replace the intake boots themselves? Hairline cracks can be hard to see but leak air. The clamps can stretch and fail to seal the boots properly. A vacuum balance requires the proper tool. See:

Air Intake Repair:
(Airbox removal, intake boots and O-ring replacement)

Synchronize Carburetors
(With the Morgan Carbtune)

Have the carbs themselves been properly cleaned and rebuilt?

Mikuni BS(CV) Carburetor Rebuild Tutorial
(Mr. Nessism)

CV Carburetor Rebuild Guide
(Courtesy of GSR and John Bloemer)
(Click here to see the CV Carb Notes)

Have the valves been adjusted?

Valve Adjustment for 16 Valve Motors
(by Mr. basic)



Thank you for your indulgence,


BassCliff

[tc.young]

Could be a sync issue, could be air/fuel issue.
Even though you used feeler gauges which will set the slides to the correct height, they can not measure the actual pull into the cylinder, of the air fuel mix. In order to do that, a good vacuum sync needs to be done. In order for the vacuum sync to be accurate, you need to have the valves adjusted. Have you done that yet?

did valves as well, don't have a carb sync so the feeler gauge was the best i could do

i didn't replace the intake boots. could i just get lazy and cover them in rtv silicone to see if that improves the situation and if it does then replace (or run?)

[mvalenti]

it will untill there is a backfire

[Maddevill]

Cleaner

You can spray contact cleaner on the running intake boots no problem. If there is a leak the idle will noticeably change. Keep track of which boot you are spraying when that happens. That's where your problem is.

[tom203]

i didn't replace the intake boots. could i just get lazy and cover them in rtv silicone to see if that improves the situation and if it does then replace (or run?)

Try spraying something on them first - like wd-40 silicone, etc- to see if it has any effects. But try some hose clamps to replace boot clamps, cuz as Basscliff said, the oldies might no longer tighten down.
Personally, a good bench sync should be adequate for a stable idle, so I think you got air leaks.

[tc.young]

i think i found the problem, i forgot to install the breather hose that comes from the valve cover to the intake box. runs better, will try contact cleaner and see if boots are leaking, hope this did the trick.

[Dave8338]

i think i found the problem, i forgot to install the breather hose that comes from the valve cover to the intake box. runs better, will try contact cleaner and see if boots are leaking, hope this did the trick.

That should have little to no effect. Many who are running pods, use a breather filter on the PCV port.

What type of air filter are you running? My gut feeling is that you are having problems getting a good seal on the air tubes at the air box. They can be a real PITA to get seated tightly and clamped tight enough so that they stay.

[tc.young]

It's a k&n stock size. Couldn't find any intake leak with the carb cleaner. I'll try again today and if it doesn't help then pull the carbs and try cleaning again

[tc.young]

hanging idle is still there, looked at replacing the carb boots, the boot from the airbox to the carb is unavailable anyone know if other model boots would fit?



looks like i need two #2 and two #3, #3 is available but #2 isn't. also part #4, i believe i'm missing those. anyone know what they are, fitch says RING OUTLET TUB. not sure what that is, maybe the cause of the leak.

[Dave8338]

You mention that you are using a K&N air filter in the stock air box. Good choice, that's what I run and have been very happy with the combo.

Is your filter oiled correctly?

[tom203]

hanging idle is still there, looked at replacing the carb boots, the boot from the airbox to the carb is unavailable anyone know if other models

Strange that inner tube (part #13881-31300 ) seems unavailable - I checked a bunch of vendors.

On my 81 650L, the similar part is 13881-31200 and appears available. I have no idea what the difference would be , but they do share the same BS32 carb.

[Steel Toed Tank]

http://www.boulevardsuzuki.com/fiche_section_detail.asp?section=94578&category=Motorcycles&make=SUZUKI&year=1985&fveh=2132

It only lists #3 as being available but as #2 & 3 take the same clamps and inserts, I would just get 4 of #3 and make them work.