fuel starvation/bad gas mileage

[teddux]

If your 450 is consuming more fuel, then you are looking in the wrong area.

[davidduarte]

If your 450 is consuming more fuel, then you are looking in the wrong area.

I was also experiencing fuel starvation, and the bike wouldn't idle properly. These are problems I need to straighten out anyway. It's long overdue to have the valves adjusted. I'm also thinking of sealing up the airbox; any recommendations on what I should use? I think the megawelcome mentions weatherstripping, but I'm not really sure what I should seal up or what I should use to seal it.

[BassCliff]

Hi,

Here's what we do on an 850....

Airbox Sealing
(by Mr. Roostabunny)

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

Thank you for your indulgence,

BassCliff

[davidduarte]

I just ordered new boots for the intake and the airbox. Should be a bit easier with a twin vs the 4. I'm a little leary about the screws holding the intake boots on; I'm sure they've never been off the bike in 30 years so I pray that they're not frozen.

[terrylee]

Soak them for a day or two with deep creep (made by seafoam people). I couldn't get an impact driver in there, so took small visegrips and got them loose enough to move with a screw driver. Or you can try a small chisel to break them loose.(just don't hit anything but the screws.) terrylee

[davidduarte]

remarkably enough, when I got home tonight, I grabbed my trusty Vice-Grips, and I was able to turn 3 of the 4 screws. The only one I couldn't turn was the right inboard screw, and I couldn't really get a good grip on it, even with needle-nose Vice-Grips. I may pull out the airbox (if I can) and try a regular screwdriver on it.

[davidduarte]

took the carbs to a friend's house today, where we took them apart, and he cleaned them with his parts washer. Replaced the O-rings on the main jet and on the drain plugs for the bowl. Went to a local Suzuki dealer and got new gaskets for the float chamber bowls, and reassembled. There had been a lot of red, gritty gunk in the bowls (I wonder if this is from Stabil, which I no longer use), and also what appeared to be hair around the filter for the needle valves. I have new intake boots, screws and O-rings, I'm waiting on the airbox boots to get here, then I can put the carbs back in. I'm going to try to get the rust out of the tank if I can, but either way I'm installing an inline filter between the tank and the carbs. If all goes well, I should be back on the road in a couple of weeks.

[teddux]

Can you post a picture of your air inlet?
Seal it.

I think the megawelcome mentions weatherstripping, but I'm not really sure what I should seal up or what I should use to seal it.

The air intake is a CALIBRATED ORIFICE, that's where ALL the intake AIR needs to come from (and maybe the air-box drain).
Any (other'n drain) air leaks between this and carbs. obviously defeats the purpose of any calibration in the system.

You then have to sync carbs.

[Clone]

The red gritty stuff is rust from your tank, you need to clean the tank. Also check the screens above the float valves.

[davidduarte]

I bought some washing soda at Stop & Shop today (I thought I'd have a hard time finding it in any store anywere, but lo and behold, it was right there in the cleaner aisle). I'm waiting on the airbox boots still; once I get those, I can put the carbs back on, then start the electrolysis on the tank. I'll post some pictures of the bike in a bit.

[davidduarte]

Here are the carbs, cleaner than they've been in 30 years:

[davidduarte]

Just installed new intake boots:

[davidduarte]

Here's what the airbox looks like:

without filter:



with filter installed:



the airbox cover underside:



the cover in place:

[davidduarte]

here's the grungy inside of my gas tank:



and some of the crud I shook out of the tank:

[davidduarte]

the intake boots do not have ports on them with which to synchronize the carbs like the 850. I'm wondering if the screws you can see near the boots is what you would remove to do said syncing.