Valve adjustment question

[SeanM]

I'm wondering, on the 1100 Kat...if the valves are seriously out of adjustment would that cause it to "miss" or "flutter" in the top end of the rev range, thereby losing significant power?
I just jetted the carbs and put a filter in, also it's running a 4-1 exhaust. It has excellent power up to approx 7500 RPM then it makes an odd "fluttering" sound and kinda "skips" it's way to redline.

Most likely valves? Or something else?

[bluekat04]

has this started when you put the jet kit in, when was the valves last adjusted.

[SeanM]

The big has never had all the power it should. And it actually works better now with the jets installed. As much as I really hate to admit it, it's been at least 2yrs since they've been adjusted. And you can hear them ticking.

[SeanM]

To add to this. I was thinking about simply taking the bike to the shop this week to have a valve adjustment done. However, I did some research on this board (very helpful) and it appears like it's really not that difficult. Is it really as easy as removing the valve cover, checking the clearance with a feeler guage and adjusting the screws and necessary?

[Steveb]

To add to this. I was thinking about simply taking the bike to the shop this week to have a valve adjustment done. However, I did some research on this board (very helpful) and it appears like it's really not that difficult. Is it really as easy as removing the valve cover, checking the clearance with a feeler guage and adjusting the screws and necessary?

And then syncing the carbs, yes. Valve adjustment will alter individual cylinder airflow.
Biggest issue is getting the darn valve cover off and clear of the frame....and then back on with the gasket intact.

[SeanM]

Perfect, well if that's the case I'll adjust them on my next set of days off then take it in for a sync, should save me quite a few $$'s.

[DClark]

And then syncing the carbs, yes. Valve adjustment will alter individual cylinder airflow.
Biggest issue is getting the darn valve cover off and clear of the frame....and then back on with the gasket intact.

Don't forget the part about putting the valve cover on without stripping out the valve journals-it doesn't take much. First, how do your plugs look? Bad plugs will act up at high rpms. Getting enough fuel? Get some duct tape and cover 1/4th of the filter opening and see if it runs better. If it does, then you are not getting enough fuel. When you did the jet kit, you committed a no-n0- now you have to figure out if the problem is carb or ignition related. Oh, how are the spark plug wires? With the gas tank off, in a dark, dark garage, run the bike and see if you see a "light show". How old is your gas? Bad gas will make it run poorly. I once had problems similar to yours that went away when I drained the tank and put in some fresh gas. Valves? Valves that are too tight can cause high rpm problems. Tight valves are like high blood pressure- they are a silent killer! I will say that once the valves have been set one or two times, they really tend to stay put. These bikes always do better with a synch, but even a bike that is as out of synch as Jessica Simpson should run fine balls out.

[SeanM]

Don't forget the part about putting the valve cover on without stripping out the valve journals-it doesn't take much. First, how do your plugs look? Bad plugs will act up at high rpms. Getting enough fuel? Get some duct tape and cover 1/4th of the filter opening and see if it runs better. If it does, then you are not getting enough fuel. When you did the jet kit, you committed a no-n0- now you have to figure out if the problem is carb or ignition related. Oh, how are the spark plug wires? With the gas tank off, in a dark, dark garage, run the bike and see if you see a "light show". How old is your gas? Bad gas will make it run poorly. I once had problems similar to yours that went away when I drained the tank and put in some fresh gas. Valves? Valves that are too tight can cause high rpm problems. Tight valves are like high blood pressure- they are a silent killer! I will say that once the valves have been set one or two times, they really tend to stay put. These bikes always do better with a synch, but even a bike that is as out of synch as Jessica Simpson should run fine balls out.

The plugs were bad but were just replaced 2 days ago. Coils and wires are new as of last summer. The gas is one thing I was considering as it's about 4 1/2 months old. however I have since run some new through it, although I didn't drain the old first. The jet thing wasn't too much of a "no-no" though as the bike was horrifyingly slow last year. It does have amazing throttle response and tons of power up to ~7K. When it's running in neutral you can rev it to the moon and it sounds beautiful, it's only under load that it "flutters"

[DClark]

The plugs were bad but were just replaced 2 days ago. Coils and wires are new as of last summer. The gas is one thing I was considering as it's about 4 1/2 months old. however I have since run some new through it, although I didn't drain the old first. The jet thing wasn't too much of a "no-no" though as the bike was horrifyingly slow last year. It does have amazing throttle response and tons of power up to ~7K. When it's running in neutral you can rev it to the moon and it sounds beautiful, it's only under load that it "flutters"

Check the plugs again and make sure they look still look good.
Gas- unless you have run a lot of gas passed that last tank, you could still have some water in the fuel- if you have water in the fuel, it can be a devil to get out, that's why I think the best thing to do is to place the tank on a large bucket, like the one that Costco puts their laundry detergent into and drain through the petcock.
Also, does the bike run better with a full tank rather than when near empty? This could intake a clogged fuel filter (which is in the tank).
You might want to run some carb cleaner in your fuel.

[SeanM]

Check the plugs again and make sure they look still look good.
Gas- unless you have run a lot of gas passed that last tank, you could still have some water in the fuel- if you have water in the fuel, it can be a devil to get out, that's why I think the best thing to do is to place the tank on a large bucket, like the one that Costco puts their laundry detergent into and drain through the petcock.
Also, does the bike run better with a full tank rather than when near empty? This could intake a clogged fuel filter (which is in the tank).
You might want to run some carb cleaner in your fuel.

I appreciate the tips. I will try it and see what I get.

[gaillarry]

I use Seafoam in the gas quite often. I use 1/3 can of seafoam in every 3rd tankful of gas. I call it the 3/3 principal. It really helps to keep the carbs clean.

[Red Barron]

Two things:

1) Valve Clearances: The Haynes manual has the valve clearances as 0.10 to 0.15 mm for the intake and 0.18 to 0.23 mm for the exhaust. The Suzuki manual has them both as 0.10 to 0.15. I'm using the Suzuki specs. Does anyone have any thoughts about that?

2) Balancing the Carbs: Where do I get the adapters to attach the gauge?

[DClark]

Two things:

1) Valve Clearances: The Haynes manual has the valve clearances as 0.10 to 0.15 mm for the intake and 0.18 to 0.23 mm for the exhaust. The Suzuki manual has them both as 0.10 to 0.15. I'm using the Suzuki specs. Does anyone have any thoughts about that?

2) Balancing the Carbs: Where do I get the adapters to attach the gauge?

Those Haynes exhaust specs sound way too loose. Follow Suzuki manual on everything except for valve cover bolt torque- they are too high and result in cam journal stripping.
Fwiw, I have set my valves at .10 intake/ .15 exhaust (as close as I could) before- this is called "staggering" and it is supposed to give a bit more tq. I have since set them both closer to .10, it feels better that way.
Carb synch- the adapters come with the gauge. If you don't have any, Dennis Kirk sells them. In fact, they even sell some nifty ones that you can leave in your carbs, making future synching easier.

[docbarlow]

The emissions sticker on my fender says .10 - .15 mm for both, no stagger (93 1100)
You also might want to check for wear on the needles and make sure the jet washers were reinstalled, wide open will be the main jet and the vac opening or spring on the CV carbs.

Needle wear will be upper midrange 5-8K

When removing the valve cover don't forget to remove the crossbar (allen bolts through the frame)

Good Luck

[DClark]

The emissions sticker on my fender says .10 - .15 mm for both, no stagger (93 1100)
You also might want to check for wear on the needles and make sure the jet washers were reinstalled, wide open will be the main jet and the vac opening or spring on the CV carbs.

Needle wear will be upper midrange 5-8K

When removing the valve cover don't forget to remove the crossbar (allen bolts through the frame)

Good Luck

On the staggering, the valves were still in spec, just that the exhausts were closer to .15 and the intakes were closer to .10. it is just something to do if you want to try something different.
As for needles, dunno.. with the Dyno jet needles (I hate Dynojet!) I wore out two sets of emulsion tubes! Go to factory.com and they have an article about emulsion tube failure, they say it is common on large suzuki fours. I pulled a tube out and the top hole looked fine at first, but under a magifying glass, you could see score marks. In good light, you could see where the needle machined it. Compared to a new emulsion tube, it was quite apparent that it was shot. BTW, I talked to a tech at Factory and he said that either the needle wears or the emulsion tube and on suzuki's it is rare to see a bad needle.
With bad emulsion tubes, the bike will rub rich. Give'er full throttle at night and look in your mirrors, you will see the smoke in the headlights.