Hey everybody. Hoping you guys can help me.

I've had an '07 s40 for a couple of years and it's been a dream. I've rejetted it several times based on whatever muffler i've had and done a number of other things to improve the way it rides, etc. So I'm no stranger to the bike.

BUT...

I recently picked up a '97 savage for a few hundred bucks and have messed with it and messed with it and I just can't get the thing to run right. I have had the head cover off and have checked the cam timing, tuned the valves to tolerances I have found on the forum - and the only reason I have been suspicious of the timing is because I've gone every which way with the carb...

No matter what I do, the bike wants to run rich (I think) because it blows black soot out the muffler. But when I lean out the carb it doesn't hardly want to run at all -  it still blows soot but won't hardly take the throttle AND THEN what is weird is that if I pull the choke it comes to life! I have checked the float height and matched my S40. I started this journey without an airbox at all, so it's getting air. I have since gotten an airbox but it hasn't changed the phenomenon. I've checked the header and muffler for blockage, all good.

The soot is it's worst at about 1/8 throttle - that's where it bogs, but beyond that it will open up. For illustration, if i jet it lean, it will darn near die at 1/8 throttle, and blow black soot... If i jet it rich, it will still blow black soot, but power thru... THEN if i pull the choke, it revs up and is almost normal.

I have not been using a petcock as I have had the tank off the bike and have simply been using a long fuel line. (maybe the problem?)

I am on my 3rd spark plug as they soot over pretty quick.

The only thing that I did notice when I had the air box off, is that the vacuum slide in the carb seemed to rapidly pulsate up and down, which i've read can be normal for a vacuum slide that doesn't get the air velocity that it does from and air box. But since adding the box, the behavior hasn't changed.

It is beyond my knowledge at this point. Clearly the engine is not doing a complete burn of the fuel that it is getting... but based on the extremes i've gone to, i don't think it is exactly fuel, air, or spark related...

To me, it would seem like it has to be fault somewhere in the ignition timing, but i have no idea how to troubleshoot that...

Help!

JOG wrote on 08/07/24 at 08:58:05:


Yep....that could tell you something.  Put the 07 carb on the 97 and see what happens.

Well as luck would have it... i threw on my known good carb, along with my tank and good petcock, and I can tell the '97 Savage is running like it should. No soot - no hesitation.

But I cleaned the 97's carb?? Is there a solution I should just dip the thing into for a few days?? There's gotta be an airway somewhere inside that is clogged...

I could just upgrade the carb, but i'd rather get the original carb working right.. at least for now.

What do ya'll dip your carbs in??

For your carb with the issues, did you ever disassemble and clear all of the tiny passageways in the carb body with a carb tool ?  If not, you need to.  A carb will not function properly unless they are clear.  Use a carb tool (or a gas welding jet cleaner tool-same type of tool), then carb cleaner aerosol, then compressed air.  

Well... after confirming with the '07 carb that the '97 bike runs great and  that the '97 carb has been my issue, I have soaked that carb body, confirmed that all passageways are clear, fitted it with all new jets based on how the '07 is jetted, put the '97 carb back on the '97...

and it still runs horrible. spits soot. barely idles... it's actually worse than it was the first time i cleaned it.

literally with the carbs side by side, the only thing i noticed is that the vacuum slide's spring is about 30% taller for the '97, but i don't know what that would have to do with the way it idles.

I guess the '97 carb is junk and I'll get a performance carb.

Unbelievable.

Screw it. Tired of looking at that carb at this point.

I've seen folks here have had success with the PWK38, which i've actually had my hands on before and I like those... I suspect that'll bring a little muscle out of the bike anyway.

I do need somebody's help finding the right manifold tho... anybody got a part number for a rubber manifold that will marry the savage and the PWK38?

ThumperLife wrote on 08/09/24 at 08:22:44:


ThumperLife - Below a somewhat recent thread from when I installed the Keihin PWK38.  Maybe it can give you some ideas and help with jetting.

I think I reference the manifold I used (it’s a Mikuni but it fits like a glove on the Keihin PWK38).  I’ll reread my own post and if I didn’t note the manifold, I can find a link to it from when I bought it.  For these cheap knockoff carbs, I do buy and use cheap knockoff jets.

To cut to the chase and without reading my thread, I’d suggest starting with:

Pilot Jet: #32 or #35 (#32 is a little cleaner and more stable idle once dialed-in in my opinion - try 1.5 turns out on the mix screw). Note:  The mix screw is opposite the stock CV carb - turning it clockwise is richer).

Main Jet: Start with a #125.  See my thread on this one.  It’s been a bit more of a challenge for me.

Needle clip - try the middle groove first.  I ended up moving to the 2nd from the top (leaner).  This one is also tricky and your needle may be different than mine (life is like a box of chocolates with these carbs - you never know what you’re going to get).

You’ll have to decide if you want to use the stock air box or do some other air intake.  You’ll see I tried both and I’ve settled in with a UNI pod filter connected directly to the carb.

You’ll also have to come up with a throttle cable mod or maybe Lancer can hook you up with a cable that he sells with the Mikuni VM36 slide carb kit.  It’ll work on the PWK38 too.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1714330191

Here’s the link to the manifold.  You might find it a little cheaper, but I’ve had good luck with Niche (and they say it’s Mikuni Brand and I believe it).  Just a little tidbit, I used stainless steel M6 flange bolts to secure it (I hate the stripable stock screws).  I think they are 16mm or 20mm.  Take the stock screws to Ace or any hardware store and match ‘em up.  

https://www.ebay.com/itm/173163117968?mkcid=16&mkevt=1&mkrid=711-127632-2357-...