Got Snork? (airbox question)

[Mr. Brown]

I'm doing my best to dial in my GS850, and you all have been tremendous.

I am missing the original rubber snorkel that was attached to the airbox. I've done a lot of work to seal the sides and ensure no leakage from box to carbs to engine. However, the airflow from the hole in the bottom of the box is a variable I want to nail down.

At the moment, about half of the port is covered (Duct Tape!) and seems to be doing fine. The plugs are a nice golden brown. I tried last week to seal up more of the slot, and crapped out the bike.

Anyone got any hints on exactly how much air should come through the slot? Better yet, Got Snork?
Thanks!
-=T=-

[mark]

No clue on how much air, your plug color and way the bike runs are the best measuring tool, actually sounds like you're doing O.K.

You might want to check on Ebay, and see if you can pick up the airbox for your model.

[twr1776]

If you can find an airbox to install that would be the best thing. If you get caught in the rain you could possibly pull water into the airbox through the bottom.. My 1000 had a missing snorkel when I got it and had a huge flatspot until I did a tempory duct tape job. I found one on E-bay. The one I got was actually from an 850 box but fit. If the side of the box looks like your box it should be the same airbox even if it is from a different model.

[chiphead]

My 1100 is missing the snorkel and at the time I had it apart I couldn't find one. Put it back together without one and had to set the pilot fuel screws to around 3 but it runs the berries. Only draw back is a bit more intake roar under heavy throttle.

[Mr. Brown]

No clue on how much air, your plug color and way the bike runs are the best measuring tool, actually sounds like you're doing O.K.

You might want to check on Ebay, and see if you can pick up the airbox for your model.

The reason I'm still tweaking the box is because even though it runs pretty smooth, it ain't right. The throttle is a little jerky, and the max speed is about 60-65mph. I've had people warn me that this bike might be a little more than a starter can handle, but she's more of a kitty than a tiger. Its like it's not translating all its effort into speed...

[49er]

I'm doing my best to dial in my GS850, and you all have been tremendous.

I am missing the original rubber snorkel that was attached to the airbox. I've done a lot of work to seal the sides and ensure no leakage from box to carbs to engine. However, the airflow from the hole in the bottom of the box is a variable I want to nail down.

At the moment, about half of the port is covered (Duct Tape!) and seems to be doing fine. The plugs are a nice golden brown. I tried last week to seal up more of the slot, and crapped out the bike.

Anyone got any hints on exactly how much air should come through the slot? Better yet, Got Snork?
Thanks!
-=T=-

With VM26ss carbs fitted ('79 GS850), the intake area of the snorkel is slightly less than the sum of the cross section area of the inlets of the four carbs. If you add the cross section area of the 8 x 10mm holes at the bottom of the airbox to the snorkel inlet area, you have an exact match up to the sum of the carb inlet areas. Now ain't that a coincidence!
Try and source a snorkel and take advantage of Suzuki getting it right.
That's assuming that a PO hasn't experimented with different jetting!

[tkent02]

An 850 that only goes 65???
It should double that, it is making only a fraction of the power it should be.
There's more wrong than a few holes in an airbox.

[Mr. Brown]

An 850 that only goes 65???
It should double that, it is making only a fraction of the power it should be.
There's more wrong than a few holes in an airbox.

Where would you look first? Compression Test?

[Mr. Brown]

After reading a few more threads, I think I may still need to investigate the air intake area. I just bought an airbox from Ebay, complete with snorkel. I'll seal that sucker up, and replace the o-rings between the engine and the carbs. I inspected them earlier, but I'll get some new ones while I'm in the neighborhood.

Several threads mentioned a bogging down over 4500k RPM being attributed to too much air, or not enough fuel. I'll also check the petcock / filter for any resistance there.

Am I missing anything?

Where would you look first? Compression Test?

[tkent02]

Valve clearances way off, cams worn so very little valve opening, no compression due to broken rings or whatever, ignition timing way way off, exhaust clogged, throttles barely opening, bird nest in the airbox, could be a myriad of things but is probably a combination of some of these, maybe others.... Does it just stop at a certain RPM or does it run out of power?
Going 65 takes roughly 1/4 to 1/8 the power it takes to go 125 or so, the engine is seriously deficient on power. If it just stops at that RPM but has good torque at lower speeds that is a different animal.
Good luck. And if you are near some experienced GS types, they may see something obvious to them that you may not have thought of.

[Mr. Brown]

Valve clearances way off, cams worn so very little valve opening, no compression due to broken rings or whatever, ignition timing way way off, exhaust clogged, throttles barely opening, bird nest in the airbox, could be a myriad of things but is probably a combination of some of these, maybe others.... Does it just stop at a certain RPM or does it run out of power?
Going 65 takes roughly 1/4 to 1/8 the power it takes to go 125 or so, the engine is seriously deficient on power. If it just stops at that RPM but has good torque at lower speeds that is a different animal.
Good luck. And if you are near some experienced GS types, they may see something obvious to them that you may not have thought of.

I've got a gasket on the way, and I'll be checking the valve clearances as soon as it arrives.

I observed its behavior closely, and it bogs at 5000rpm regardless of speed or gear. I've had the carbs off a few times and the throttles seem to be fine. I haven't looked at the exhaust yet, although I know I have a small hole underneath my left foot peg. I can't believe this is hurting anything.

I'll report back post-airbox retrofit and valve check.

[Mr. Brown]

So I got the new airbox on. I took my time with this one as I didn't want anything to keep me up at night. I made sure there were no gaps in the seal between the box and the filter, and used silicone caulk to seal around the boots and the box. I also used automotive weatherstripping to ensure no leaks around the lids... so now the only air is coming in through the snork and the holes at the bottom...

What a huge difference! \\/ She'll go 85 on accident. I have yet to get on the beltway and see what sustained high speeds are like, but this is a whole new bike!

So now there's the euphoria of knowing that the engine really will work like it should... and the depression of moving onto the next quirk. That is, she doesn't charge herself. I KNOW, I KNOW, stator papers... got it. I've kinda ignored this issue and lived off the trickle charger as I was only making short trips anyways.

On to the next fix. Thanks to everyone for their input so far...

[49er]

So I got the new airbox on. I took my time with this one as I didn't want anything to keep me up at night. I made sure there were no gaps in the seal between the box and the filter, and used silicone caulk to seal around the boots and the box. I also used automotive weatherstripping to ensure no leaks around the lids... so now the only air is coming in through the snork and the holes at the bottom...

What a huge difference! \\/ She'll go 85 on accident. I have yet to get on the beltway and see what sustained high speeds are like, but this is a whole new bike!

So now there's the euphoria of knowing that the engine really will work like it should... and the depression of moving onto the next quirk. That is, she doesn't charge herself. I KNOW, I KNOW, stator papers... got it. I've kinda ignored this issue and lived off the trickle charger as I was only making short trips anyways.

On to the next fix. Thanks to everyone for their input so far...

Well done. The 850's really perform well once you sort out the correct air/fuel ratio across the whole rev range.
Do some plug chops at various rpms to check that your jetting and needle positions are correct.
Do an integrity check of your battery first before you rip into the stator/regulator senarios.
Good luck.