The best laid plans of mice and men...

I posted in "other bikes" asking for any info specific to the Suzuki Katana 600. I'll put this in general discussion as it could apply to any bike.

This bike(Katana) was bought for the sole purpose of having something to ride whilst I labored over the Seca's carbs and such. Well, I got the first ride in over 20 miles yesterday and have some serious issues.

I burned 6gal of 93 oct. petrol on a 50 mile round trip. There is an oily, black liquid condensing in the mouth of the exhaust can. The bike idles smooth and runs like a raped ape. Sweet throttle response and serious engine braking. I hit 100mph in 4th gear with out even realizing it with 2 more gears to go and not even close to redline.

The oily exhaust points to a head gasket in my mind. could that also cause the low mileage? I would have thought that performance would suffer drastically also. Though it is possible that what I am taking for good performance may not be, as I have never ridden a Katana before.

I'm going to strip the fairings and give her a compression test this afternoon.

 

So, you figured because it was only 11 years old not 30 that it would be a simple, "turn-key" proposition?

Doesn't that bike have CV carbs and tubeless tires?

How many miles? I would say if you get good compression numbers but it's pushing oil, it may be a bad valve stem seal or two. How do the plugs look?

 

8.3 MPG ?? that's what my Veyron gets - -

Are you DRIPPING gas?? Post pics of your plugs,
any tricky tank vent system??

Fueling error - -I once put 6 gallons in a 4 gallon tank. I complained to the manager. He did NOT want to hear it - no refund.

 

Just a quick reply as I have not checked the plugs or compression yet (after work).

Fitz,
9400 mi.
Carbs(Mikuni?)
Tubless tires 3yrs old and plenty of tread left.

Lets just say that I hoped to get a season of fairly maint. free riding out of it. The PO was not the Original owner. He had it for 5 years and only put 2000+/- mi. on it. I have known him for 3 years and while we are not close friends I have seen enough of him to know that he takes care of his toys even though he is not mechanically inclined. Regular oil and filter changes, etc.

TIME,
No fuel dripping. The petcock is operating normally and I checked the capcity and fill level in the owners manual before fueling. The first thing I looked at was the petcock thinking the vac valve was stuck open. Nope it shuts up tight, no drips. And it does not appear to have any complitcated tank venting system.

I will be tracking down a factory service manual ASAP and have a Haynes on order.

 

Nah, something's up bud....8 miles to the gallon? Heck, my H2's get 18-22. Imagine that, a bike getting worse mileage then a H2 triple<LOL>. I'm going to guess that your gas station display is wrong. I filled my 5 gallon fuel tank with 6.7 gallons and my little 2.5 tank with 3.4. I brought out the mideastern guy to look at the tanks and pump and amazingly, he ceased to speak English....<lol>. I THINK they are allowed a +/- 10% error.

You could very well be running rich(but it would be blubbering like a baby up at high RPM and not running well if it were THAT rich) or have lost a valve seal causing the visable oil but neither could take you down to 8mpg. I got a feeling that someone is getting too greedy.

Please be sure to let us know what you find.
jeff

 

JeffK,
I filled the tank to the neck of the filler tube per the owners manual. I didn't go by the pump read out. She ran down to Reserve and I refilled about 6 miles later, again to the neck and the pump read 4.9 gal. The rest of the trip dropped 1/4 tank by the fuel gauge. 5.3 gal tank.

I cant see how a valve seal or head gastket could have that effect on mileage without any apparent effect on performance.

I keep thinking that there has to be a fuel leak somewhere and I just haven't found it yet. I cant see any evidence of fuel on the rear tire or find any drips but with all the covers and cowls it may be running out somewhere completely unexpected. That's why I'm pulling all the plastic off this afternoon.

 

This is not my week!

The starter in my just paid off car took a crap on me today. Yay! So I didn't have the time I wanted to spend on the bike.

Well, I got the body plastic off and found some oil seepage from the head gasket around the #1 exhaust. No sign of a fuel leak anywhere. All the fuel line is solid.

It turns out that I do not have the correct size adapter for my compression gauge so that will have to wait for tomorrow. However, I did find that the #2 plug was fuel fouled. 1,3 and 4 looked good if just a tad rich. I fired it up and immediately felt the header pipes. 2 was ice cold. The plug is sparking when removed from the head. I'll wait for my Haynes manual to arrive to see what the best swap procedure is for checking the ignition coils. Not sure if the wires are replaceable or not.

 

8.3 MPG? Keep us posted. I can't see how that would be possible without a very serious fuel leak that would be clearly visible to the naked eye. If it was simply a matter of some PO jetting the carbs incorrectly or adjusting the fuel mixture screws wrong I think you would be fouling the plugs like crazy and see fuel spraying out your exhaust.

 

mirco,
It looks to me like the factory anti tamper plugs are still intact on the mixture screws. The immediate PO says he made no mods at all but doesn't know what the first owner did other than a smaller rear sprocket and bobbing the rear fender.

 

If #2 plug fires thats not it. Sounds like your pumping raw fuel with #2 carb right out the tail pipe. Have you checked your oil level yet? might just be your idle jet is lose or fell off even. Lots of folks dont realize this but these engines will run pretty decent on 3 cylinders and if thats your case wait till you get the forth cylinder working Look out. Best of luck to ya

 

You don't need to wait for Haynes.

The Coils will "Swap" quite easily.
Unplug them from their Harness Connections and swap the Plug-in's.

The 1~4 Coil will fire the 2~3.
The 2~3 Coil will fire the 1~4.

Take the Vacuum Hose to the Petcock off the Manifold and "Take a few drags" on it.
If you taste gas, ... the Petcock Vacuum Membrane has a puncture and gas is getting sucked right into the Manifold.

That's a big "Gas waster" hard to detect.

 

Thanks Rick.
I never thought to check the vacuum side of the petcock. Since it shuts the fuel off I just assumed it was functioning normally.

 

"I filled the tank to the neck of the filler tube per the owners manual. I didn't go by the pump read out. She ran down to Reserve and I refilled about 6 miles later, again to the neck and the pump read 4.9 gal."

My God, it's getting worse! It's down to .81 miles per gallon!

I'm just teasing you lvmy40, I figured out what you MEANT to write.....just trying to keep it light as you solve the mystery.

jeff

 

have you checked that yr speedo is clocking up right? i wdnt of thought it would be that far out,without u noticing but it maybe out enough to make it look worse than it is?

 

should have saved receipt, taken picture of bike at pump and threaten to report their fraudulent tank, gotten refund and report anyways!

 

That gas is going somewhere. Check your oil I bet the crankcase is filled with gas

Dont ride it again until you do

 

Someone is trying tell me something! Yesterday the car quit (its an ignition actuator in the steering column, not the starter evidently), today I get home and go out to swap coils and there sits the key in the ignition(yes, it was in the ON position!). So, out comes the battery and hooked up to the charger it is, only the charger's on the fritz too(cheapass Harbor Freight charger).

Anyway the coils are swapped and as soon as I get the battery charged I'll try it out. I couldn't find the adapter for my comp. gauge locally so it will have to be ordered.

I'm sure that the speedo is not clocking properly, at least for MPH. The smaller sprocket throws it off by a good bit. I haven't determined how far out it is yet. I would have to assume that this effects the odometer also. However the round trip to and from my employer is a known factor, exactly 50.3 miles portal to portal.

 

I did change the oil. It smelled like fuel but there was very little added volume. I drained just about 3.5 qts. and the manual calls for 3.5/3.7w/filter.

 

The problem didn't follow the coil. #2 still not firing.

 

I picked up a new compression test gauge with the right size adapters. The compression reads 135psi on 1,2 and 3 and 140psi on 4. The manual specs 142psi to 213psi as standard and 114psi as service limit with a max differential of 28psi. So I am low but not horribly so. I have no idea if the valve clearances have ever been check or adjusted.

I may pick up a used coil on fleabay just to try out as the coils do have two different part nos. The only difference may be the cylinder labels but I haven't verified that yet.

waldo mentioned that it may be a loose or missing pilot/idle jet. I took the carb hat up and the diaphragm is solid and the piston/needle is clean and secure but I cant see anything else from the topside. I guess I'll pull the air box and carb rack tomorrow. At least the air box is an easy removal!

 

You get the Gold Star waldo!

I pulled the carbs and found the pilot jet in carb #2 had come out and was keeping the float valve open. It's all back together and purring nicely. I am going to change the oil and filter again before riding it.

 

Glad that you found the problem, and especially that you posted up on what it turned out to be. A lot of guys get "fixed" but never bother to let everyone know what the deal was. I think Waldo should get TWO Gold Stars....one for guessing the Pilot jet and the second for realizing that ("Lots of folks dont realize this but these engines will run pretty decent on 3 cylinders") we were assuming that you were correct when you had thought that it was running fine ("The bike idles smooth and runs like a raped ape. Sweet throttle response ") when in truth, it was only idling on 3 cylinders.

good lesson....

jeff