Bike miss-firing, advice?

[norcalwelder]

I noticed something else, when I synch the throttle bodies at idle, they got massively out of synch as the throttle is increased. In order to get everything synched, cylinders 2 and 4 screws have to be almost bottomed out as well. Not sure what to think, lots of clues but I can't put the pieces together.

 

[TownsendsFJR1300]

The last two FZ's I've synced (my 07 and a 06) , the #4 cylinder seems to pull more at 4,000 RPMs than the rest, adjusting one, WILL effect the others. Another poster, about a week had the #4 pull a but harder too so that's NOT unusual. Two days ago, we got the 06 within 2mm's at idle andat 4,000 RPM's, still had a little bit of a loppy idle.

I check and adjust again @ 4,000 RPM's and even them up (as that's where alot of buzz is where I was experiancing). Let it idle down to 1300 and check and re-adjust as necessary.

I believe I read somewhere, opening the #1 screw (generally a NO NO) allows more adjustment to the rest but I can't confirm this. Please check the # of turns out STOCK AND RECORD IT before playing with it.

Just as an FYI, quite awhile ago, a member took the adjuster "box" apart (for the air screws) and found all kinds of goo inside. Once cleaned out, worked 200% better, adjustments worked too!

 

[norcalwelder]

Hmm, I would be interested to see if my adjustment manifold needs cleaning... I know its never been done, that is for sure. With 56000 miles on the bike, it might be time. I've been using my homemade carb tune, but the guys at work suggested I bring the bike in and use our set of gauges, and make sure the number 1 cylinder is where it needs to be. I was really surprised to see 4 to 5 inches of difference in pressure when I revved her up with it synched within several mm at idle. Granted, my manometer is filled with hydraulic fluid so it is pretty sensitive, but still.

 

[trepetti]

During my last tb sync I KNOW the #1 screw got turned. Is there a proper way to reset it?

I am confused about why it should not be turned. The shops jail says to use it as a reference, but I think that is just process. How could it be that all the tbs will go out of sync except the first?

 

[norcalwelder]

Great question....I have no idea.

 

[REO Scorpio]

During my last tb sync I KNOW the #1 screw got turned. Is there a proper way to reset it?

I am confused about why it should not be turned. The shops jail says to use it as a reference, but I think that is just process. How could it be that all the tbs will go out of sync except the first?

Always wanted to know of a reset procedure as well. I started to adjust my #1 the first time I did a sync and always wondered if it could be set back to factory without a flow bench.

 

[TownsendsFJR1300]

During my last tb sync I KNOW the #1 screw got turned. Is there a proper way to reset it?

I am confused about why it should not be turned. The shops jail says to use it as a reference, but I think that is just process. How could it be that all the tbs will go out of sync except the first?

One of the times I synced my bike, I tried to bring the vacuum to factory spec's at idle. Adjusting everything BUT #1, kept the vacuum(as I re-call) below spec's. I messed with #1 (and of course didn't check the # of turns out, the book is messed up as it states something to the effect of # of turns IN). BTW, I never got it to the overall specified vacuum #.

Even with playing with the #1 screw, I couldn't get the vacuum where its specified. I ended up leaving#1 at 3/4 a turn out.

I've read (forgot where, #1 should be like 1-1.25 turns out). I thought about re-adjusting it out to 1 turn but it runs SO GOOD at 3/4, I'm not messing with it. Again, IMHO, 3/4 to 1 turn out (for #1), you should be ok.

The re-sync at 4K, IMHO should be mandatory. In the several FZ6' I've synced, ALL have had the #4 cylinder pull harder than the rest at 4K. A little more fine adjusting brought them all in line at 4k (usually within 2mm's) and at idle.

Although I keep my idle normally at 1,000 RPM's by choice, I sync the idle at 1,300(the specified idle speed) and later turn it down.

Reading thru the Carbtune manual, I've found you may not be able to bring the vacuum up (or down) no matter what but it really isn't important. Just getting all cylinders to pull as close as possible (10mm spec limit per the manual), unless you have out of adjustment valves, ignition issues, etc, is very easy to get to. All of the FZ6' I've done have been within 3mm's at idle and 4K RPM's..

Yamaha likes the bike on the warm side when doing this, however, I've found it takes a bit longer (depending on the bike). I have a heavy duty fan thats set on high, placed right in front of the header/radiator to try and keep temps within normal riding temps.

Re the sync componant itself, do a search, it was awhile ago, with pictures. As I re-call, it wasn't anything super major to do and the goo that was in there, was quite nasty...

 

[TownsendsFJR1300]

Always wanted to know of a reset procedure as well. I started to adjust my #1 the first time I did a sync and always wondered if it could be set back to factory without a flow bench.

I think, being the FZ6 has only TWO, two barrel throttle bodies connected with ONE screw and spring, on a flow bench, your obviosuly going to get the butterflys lined back up(if out of "sync") where they should stay.

I don't know if the flow bench would show the effects of the air screws. Even if it did, once the TB's are bolted up to the engine, each engine runs slightly different and I'd be sure you'd have to re-set the air screws in either case.

Just as an FYI, my old FJR 1300 (4 cylinder) had 4 separate throttle bodies and with that comes THREE butterfly adjustment screws that YOU DO NOT ADJUST.

The factory actually puts a stripe of white paint on each of the adjustment springs. Syncing is done with air screws at each TB (much more difficult than the FZ as their kinda down deep with caps on each TB.

I haven't noticed if the FZ6 has paint on the one, center, butterfly spring but I would suspect so. DO NOT ADJUST THIS SCREW unless its known someones already messed with it.

I also would think, if cylinders 3&4 are way out of sync from #1&2 and cannot be adjusted close to each other, its very likely, someone messed with that screw and now the butterflys themselves ARE NOT LINED UP.

NOTE, When I had a YAMAHA shop (with Yamaha mechanics) sync my bike (I had an ignition issue under warranty, they would touch it without first doing a sync). Of course I couldn't see what they did. I later found out (after I got my carb mate, the YAMAHA MECHANIC, turned one butterfly screw, between TB #1 (the paint was broken on the spring) which, like the FZ6, is a BIG NO NO. I ended up adjusting that butterfly screw back to where the paint line up again and adjusting the AIR SCREW, which should have been done the first time..


**I don't think I have answered your initial question, but it has been brought up on the FJR site I frequent. The factory of course doesn't want you adjusting it, BUT, one of the really, really bright wrench turners on the FJR site came up with a method:

You pretty much remove the entire TB assembly from the bike AS ONE UNIT. Turn the idle screw up some (to allow access of a wire feeler gauge), then with a feeler gauge, slip the feeler gauge between each thottle body and the butterfly of each TB and adjust the screw (the spring loaded adjustment screw) until you get the same gauge setting across the board.

 

[stink989]

The easiest way to check the spark is to cut off the part of the plug that goes from the outside at the bottom of the plug to the middle. That will give you a good gap for it to jump.

The feeler gauge set up for the throttle bodies is the only way to set fuel injected butterflies when that have been played with. It is also a great way to set up a bank of carbs when they have been ripped apart on the bench before refitting them.

I would also check the pick up coil resistance as they can make them run rough when warm and cause really rough idle. I have even seen what looks like grease on them but is actually tiny pieces of swarf causing it send the power to earth. (Not sure of a weak signal will cause an error code like an open circuit does)

 

[norcalwelder]

One of the times I synced my bike, I tried to bring the vacuum to factory spec's at idle. Adjusting everything BUT #1, kept the vacuum(as I re-call) below spec's. I messed with #1 (and of course didn't check the # of turns out, the book is messed up as it states something to the effect of # of turns IN). BTW, I never got it to the overall specified vacuum #.

Even with playing with the #1 screw, I couldn't get the vacuum where its specified. I ended up leaving#1 at 3/4 a turn out.

I've read (forgot where, #1 should be like 1-1.25 turns out). I thought about re-adjusting it out to 1 turn but it runs SO GOOD at 3/4, I'm not messing with it. Again, IMHO, 3/4 to 1 turn out (for #1), you should be ok.

The re-sync at 4K, IMHO should be mandatory. In the several FZ6' I've synced, ALL have had the #4 cylinder pull harder than the rest at 4K. A little more fine adjusting brought them all in line at 4k (usually within 2mm's) and at idle.

Although I keep my idle normally at 1,000 RPM's by choice, I sync the idle at 1,300(the specified idle speed) and later turn it down.

Reading thru the Carbtune manual, I've found you may not be able to bring the vacuum up (or down) no matter what but it really isn't important. Just getting all cylinders to pull as close as possible (10mm spec limit per the manual), unless you have out of adjustment valves, ignition issues, etc, is very easy to get to. All of the FZ6' I've done have been within 3mm's at idle and 4K RPM's..

Yamaha likes the bike on the warm side when doing this, however, I've found it takes a bit longer (depending on the bike). I have a heavy duty fan thats set on high, placed right in front of the header/radiator to try and keep temps within normal riding temps.

Re the sync componant itself, do a search, it was awhile ago, with pictures. As I re-call, it wasn't anything super major to do and the goo that was in there, was quite nasty...

I've been trying different search keywords, but I cant lay my hands on that write up! I can't understand why my throttle bodies go so far out of synch as soon as I change RPM, but I am going to go back out in a minute and try again. Also, when I move a TB synch screw, all the levels will tend to wander a little bit, rather than just change to a new level. Normal?

 

[FinalImpact]

I've been trying different search keywords, but I cant lay my hands on that write up! I can't understand why my throttle bodies go so far out of synch as soon as I change RPM, but I am going to go back out in a minute and try again. Also, when I move a TB synch screw, all the levels will tend to wander a little bit, rather than just change to a new level. Normal?

^^ VALVE TIMING!

In another thread you mention a tick that can not be solved. Valve timing covers BOTH of these issues. And when you have two valves per intake and exhaust, this can really have an impact on vacuum at idle vs vacuum at RPM. The valve with minimal clearance (say intake) will open before the other, yours having an audible tick implies a valve is late to open due to excessive lash.

Check the lash making certain the cam & crank are indexed properly and IIRC the MANUAL is WRONG for the S2 as it has the user turning the engine the wrong direction.

Anyway, adjust the valves, then do a sync. But also confirm the TBs coupler to the intake is tight. Air leaks will cause sync issues too. If you really think the TWO TB's are out, remove them and flow test them with alcohol. i.e. yes, feeler gauges can work but they won't do it well so here is an option ive done in the past.
Meter in an exact amount of liquid; lets say 50cc of isopropyl alcohol and time how long it take to leak through one side vs the other. Now we are talking FLOW vs a static measurement via feeler gauge. Of course an actual flow meter and a controlled vacuum source would be ideal but few of us have that.

IMO engines that RUN on a given ignition coil SELDOM if ever show resistance issues. In fact rarely if ever is that the issue. Arc over, arc through, and/or material break down is the issue - pick your wording but when the secondary ignition coil energy is not delivered to the plugs electrode at the plugs gap, this is VERY OFTEN the fault. Two problems; its hard to test as we don't have the right tools to test it and it is RANDOM! When materials first begin to fail they only leak during high load conditions creating misfires. Usually this are off idle under acceleration or when pulling up hills, taking off, or when the gas quality sucks.

So - WE ALL KNOW the Ignition on these is WEAK. DO NOT EXCEED THE RECOMMENDED PLUG GAP as the design can not handle it!!!!
0.028" is MAXXXXXXXXXX!
Here are my stock plugs at 15,000 miles. WORN WAY beyond spec! Gap went from 28 to 0.038".... In my case, no harm no foul but that is not true for everyone.

Done for now....

 

[TownsendsFJR1300]

I've been trying different search keywords, but I cant lay my hands on that write up! I can't understand why my throttle bodies go so far out of synch as soon as I change RPM, but I am going to go back out in a minute and try again. Also, when I move a TB synch screw, all the levels will tend to wander a little bit, rather than just change to a new level. Normal?

I looked at the parts fisch, its one unit so it doesn't show an internal breakdown. I think as long as you go slow, take pictures and notes it should come apart without too much of a problem for cleaning. I wouldn't use carb cleaner either, its sometimes pretty hard on rubber and plastic parts, maybe brake cleaner if you need something aggresive or just a toothbrush and gasoline...

Re the sync, just the slightest change with the air screws and RPM's will cause the sync tool to jump/move. Wandering to another cylinder after adjusting an adjacent screw is not unusual at all. They all work together, adjusting one with more vaccum makes another cylinder work less. That's exactly why I set up a large fan in front of the bike, it just takes time doing the very fine tuning your doing.

Most shops will get it within 10mm's (the outside spec's) and call it a day. If your insdide 10mm's, technically your ok. The buzziness I was getting, especially thru the seat, almost had me sell the bike it was that annoying. The fine tuning got rid of 90% of it easily...

Between EVERY adjustment, I give it a rev or two, to settle down to where it wants to be. At the 4K check, (last week when I did another members FZ6), I had him hold the throttle at EXACTLY 4K RPMS and did some adjustments not only to #4, (the main one with more vacuum), but had to adjust 2 and 3 accordingly WITH #4 to get them to even out. Again, rev a couple of times, hold it steady at 4k for 2-3 seconds and watch it level out and adjust accordingly.

Pretty much, if their even at 4k, there just about dead on at idle. I eventually got them all within 3mm's at a STEADY 4k RPM'S, with maybe 1-2 mm's of a cylinder jumping (not dead steady)6,000 miles on the clock, first sync.

Can you get yours fairly even accross the board at about 4K and if so, how much (in mm's) are the cylinder(s) jumping up and down? Also, are you getting jumping about at 1,300 RPM's (idle) and if so, how much (again, in mm's?)

BTW, I looked for that thread but couldn't find it. I know it was in this forum as the FJR doesn't have that adjustment block(so it isn't over there)

 

[TownsendsFJR1300]

I noticed something else, when I synch the throttle bodies at idle, they got massively out of synch as the throttle is increased. In order to get everything synched, cylinders 2 and 4 screws have to be almost bottomed out as well. Not sure what to think, lots of clues but I can't put the pieces together.

I recall reading on the FJR forum, if your bottoming out on some air adjusters, open the main (in this case, the #1 screw) some and you'll have MORE adjustment with the rest.

As noted earlier, my # 1 is set at about 3/4 turn out. I've read it should be around 1 and/or slightly higher.

 

[TownsendsFJR1300]

Re Randy's post, #31, +1 re the valve adjustment.

If their too tight (beyond spec's-they tend to tighten up with wear) they'll be some overlap and will cause vacuum to be screwed up big time. A compression test would quickly show if there's low compression in a cylinder (valve overlap, carbon buildup or ? ) . Obviously, a feeler gauge at the camshaft is really needed.

You certainly have enough miles on the engine to check them (if you haven't already checked them in the last 25,000 miles).

All the FZ's I've synced were low mileage: approx 5,000 miles, then 12,000 same bike, my 07, and the most recent, a 2006 model had 6,000 miles so I know the valves weren't an issue-mileage wise anyways and both bikes ran fine short of mine with the buzz.

Good luck and please post what what you come up with...

 

[FinalImpact]

I recall reading on the FJR forum, if your bottoming out on some air adjusters, open the main (in this case, the #1 screw) some and you'll have MORE adjustment with the rest.

As noted earlier, my # 1 is set at about 3/4 turn out. I've read it should be around 1 and/or slightly higher.

I'd guess the factory sets this based upon measured emissions output and meeting the spec. Too lean and the HC values go up. To rich and the Nx emissions climb. To lean we stumble and misfire off idle under load, too rich and it stinks! The method below works from a driveability method and is also pretty close emission wise. This AFTER valve adjustment, solving any ignition issues, AND knowing the TWO TB's butterflies are matched FLOW WISE!!!

If #1 is off and requires adjustment, connect a T to the manifold (tap into the vacuum sensor line) and set #1 based upon highest idle in combination with highest intake manifold vacuum. I am not saying turn the idle speed. I'm saying set all air screws to say 1 turn out, set idle speed screw to something reasonable like target (1300 RPM). Now adjust air bleeds for highest intake manifold vacuum. Once this is rough set, proceed with TB sync.

In short if we maintain the same idle speed and adjust the air screws for the highest intake manifold vacuum - that is usually a pretty safe bet that the air bleeds are adjusted close to correct.

 

[norcalwelder]

First off, Scott, thanks for all the information! You have some awesome insight to this stuff and I appreciate you taking the time to type it all out for me. As far as the valves, I checked them several thousand miles ago and they were all loose, not tight. However, it was late at night, I was scared and tired because I had just retimed my cams after putting on a new timing chain and I didn't have any shims, so I put it all back together. I would say I should pull it apart, measure everything again carefully, and then pull the cams, get the shims, and put it all back together. Since its my every day vehicle, its a little tough to have it out of commission, but I can make do for a couple days while shims come in I suppose. The alternative is to spend 80 bucks on a shim kit, but that would keep me from waiting on shims.

Afterwards, I will synch the TBs again and see if anything changes.

My spark plugs are new, and gapped, and I put in a set of coils I got from a wrecked bike because I suspected mine were dropping a spark from time to time. The new coils seemed to cure the lumpy idle FWIW.

For today, I will go back and re synch the TB's since that is something I can do right now. I will try to record with pictures the different measurements and I will follow your write up and see if it makes a difference. The bike is completely rideable as it is, but my pilot side will not let me settle for "good enough" when it comes to my machinery!

 

[norcalwelder]

I'd guess the factory sets this based upon measured emissions output and meeting the spec. Too lean and the HC values go up. To rich and the Nx emissions climb. To lean we stumble and misfire off idle under load, too rich and it stinks! The method below works from a driveability method and is also pretty close emission wise. This AFTER valve adjustment, solving any ignition issues, AND knowing the TWO TB's butterflies are matched FLOW WISE!!!

If #1 is off and requires adjustment, connect a T to the manifold (tap into the vacuum sensor line) and set #1 based upon highest idle in combination with highest intake manifold vacuum. I am not saying turn the idle speed. I'm saying set all air screws to say 1 turn out, set idle speed screw to something reasonable like target (1300 RPM). Now adjust air bleeds for highest intake manifold vacuum. Once this is rough set, proceed with TB sync.

In short if we maintain the same idle speed and adjust the air screws for the highest intake manifold vacuum - that is usually a pretty safe bet that the air bleeds are adjusted close to correct.

I might be able to borrow a set of vacuum gauges from the motorcycle shop and check the number 1# MAP. After I get all the valves close to eachother and within specs, this seems like the next step.

 

[TownsendsFJR1300]

Please read this thread, specifically post #9, halfways down (Freds).

There's some other very good information in there.

"Fred", BTW, is one of the most knowledgable folks on the forum. There's also some other good links there as well as tips:

TBS problem - Technical/Mechanical Problems - FJRForum

 

[TownsendsFJR1300]

First off, Scott, thanks for all the information! You have some awesome insight to this stuff and I appreciate you taking the time to type it all out for me. As far as the valves, I checked them several thousand miles ago and they were all loose, not tight. However, it was late at night, I was scared and tired because I had just retimed my cams after putting on a new timing chain and I didn't have any shims, so I put it all back together. I would say I should pull it apart, measure everything again carefully, and then pull the cams, get the shims, and put it all back together. Since its my every day vehicle, its a little tough to have it out of commission, but I can make do for a couple days while shims come in I suppose. The alternative is to spend 80 bucks on a shim kit, but that would keep me from waiting on shims.

Afterwards, I will synch the TBs again and see if anything changes.

My spark plugs are new, and gapped, and I put in a set of coils I got from a wrecked bike because I suspected mine were dropping a spark from time to time. The new coils seemed to cure the lumpy idle FWIW.

For today, I will go back and re synch the TB's since that is something I can do right now. I will try to record with pictures the different measurements and I will follow your write up and see if it makes a difference. The bike is completely rideable as it is, but my pilot side will not let me settle for "good enough" when it comes to my machinery!

No problem and your welcome.

if you just checked the valves recently you should be ok. If you want to verify spec's (just so your not chasing your tail, thats fine too).

**Make sure the front run on the cam chain is taught from the exhaust cam to the crank too for checking the marks on the #1 cylinder at TDC (cam lobes facing away from each other).

Better to be on the loose side of spec's for the valves as they tend to tighten up with age/miles.

Read my post above, #38, from an FJR forum and click on that link. About halfways down, it mentions about crap getting in the orifices and how to clean it very quickly and easily besides some other tips...

 

[norcalwelder]

Here it is while it warms up.

Warmed up

http://i133.photobucket.com/albums/q42/timpowell1/PhotoJul0422355PM.jpg

After adjusting, blipping, adjusting, blipping, etc, starting to get close. This is during the adjusting. The next picture is where it settled after a quick blip on the throttle.

Where it settled after a quick little blip on the throttle.

In a little bit I will have a video uploaded after this point where i show the adjustment as it gets closer.