Top end rebuild (Stuttering, Elec. Issues Prior) (Pic heavy)

cut 1/2 inch off the end of the hose, and put it back on with a clamp.....you could have a small vacuum leak, and that is the popping noise that you hear (lean pop) .....I feel you are close to fixing all of your problems.

Kenneth

 

Re-checked all the vacuum hoses.

Checked breather hose

Put on new wiring harness

Got another new, better battery

Found a stock air filter

Nothing. No change.


I am so close to parting this out.

 

Backfiring thru intake = burned valve or a cam that is severely out of time.

Why not put a vac/pressure gauge on that #1 intake (might need a T-fitting) and watch what happens in real-time, see if you can isolate anything.

Would also put the vac/pressure gauge on the other intakes to do a comparison.

Assuming that there's not a mini-turbocharger hidden somewhere, you shouldn't have positive pressure in the intake system.

 

Nooooooo

I love this bike.... love this thread..... hate that there's no solid answer yet...

Have had this feeling/instance on mine too but like I said, a wiggle of my spark plug wire's and it's gone away... **knock on wood**


Have you tried capturing it on vid??? Is it sporadic enough you can't do it??


If you do scrap the bike, I got a parts list for ya, hahaha

 

OH THE EMOTIONAL ROLLER COASTER I AM ON

I made the decision that I will not part it out. At this point, there has been too much time and money put into it that I need to give it a rest for a while. But along the same lines, there has been so much time, money, and effort put into it that I just can't part it out! Why would I even consider it!

Through all the trials and tribs, I could be so close to the answer. I'm not going to give up on that chance, even if the bike sits for a while.

The plan for now: Keep my eye open for another bike.

There are always Seca II's on the market in my neck of the woods. One or two of them are always parts bikes, too. Before too long I might snag one and combine parts. Mine is in really good shape, brand new tires, no modifications. If it turns out to be engine related, slap the engine from the parts bike into my frame, and then rebuild my engine. A good running project/parts bike would get me a working mode of transportation, and give me the no pressure time to rebuild my engine...just start from the bottom up, really.

This whole time the XJ has been down (or the majority of the time, really), I've been borrowing a '95 Ninja EX500 from a buddy of mine. It has some get up and go. Fairly comfortable. More pressure on the wrists because of the stance. I've probably put close to 2k miles on it lol.

But I just sit on the XJ...there is no other bike like it, really. It balances so well. The posture feels good on the back and hands. The foot position in comfortable. Even putzing around on it during my lunch break at work while diagnosing and testing -- I know know it needs to be road worthy. I've ridden a ton of bikes...nothing feels and handles as well as a Seca II.

I have tried to get some video. Audio is the issue. Being able to hear the stutter while there's tons of wind noise. I have an idea or two which I'll try tomorrow.

The next things to try on it are take-my-time things. Like rebuilding this extra rack of carbs I have completely. Splitting the rack and replacing throttle shaft seals, investigating the enrichment plungers, ect. The only other thing besides that is splitting the case and making sure I haven't spun a bearing or something. Its just every time I think of what it could be, it contradicts what I've already found out, and then I start to think of something else but realize I already checked that a thousand times, and so on and so forth.

I'm in the mindset that this needs to be fixed RIGHT NOW, because at the moment it's my only transportation. I was in the process of rebuilding the engine on my Chevy K1500, when some joker -- get ready for this -- stole the transmission. Yep, you heard me right. I ended up just having to scrap the truck because well, I was minus a transmission, and it got vandalized pretty good before that. Shortly after, I bough this XJ. You guys helped me get it running one year ago, and it ran SUPER for a year. Then I hopped on it and rode to Pennsylvania and that's where it went hoolllddd onn thheeerree missteeerrr lol. I think the best thing for me right now (like I already said) is to find another bike, and then take my sweet time on this one. Trying to rush and figure out what's wrong with it might have me missing some important steps.

Sorry for the long post lol.

Edit afterthought: I sure as heck don't want people to think any of the procedures or methods in this thread aren't useful because I haven't had any positive outcome yet. It's just that wherever this issue is coming from, I've haven't touched there yet. It's in an unknown region. The stuff I've learned about bikes, engines, new techniques, and tricks about this bike in particular -- oh man, throw all the parts in a bucket and I'll put one together from scratch. Sure it's not running yet, but what I've learned in this process almost...almost justifies it borking. At the end of the day I can feel good about that.

 

Guud call man...

I hope for you.... I really do...

I love the seca.... such a smooth bike, different, I get old and young rider's that are intrigued by it all day long.

Take a break, go ride, think inside that helmet of yours and see what might occur...

Don't part it, I was kidding of course... all your parts are so pretty damn straight I'd take em but don't do it!!!

 

I don't think the problem is something you haven't touched yet.

I think the problem is somewhere there, right in front of you, being masked by an assumption.

What have you "crossed off the list" because you're assuming it has to be fine?

I'm only asking because I've assumed myself into a corner more times than I can count. "Oh, it can't be that because..."

Let's go back over the whole thing: The bike ran fine before the trip.

What happened on the trip that stands out in your mind? Did the problem come on suddenly, gradually, or not surface until you got home and then rode the bike after?

Describe the "stuttering" more thoroughly, please.

It's not mechanical is it, like maybe you wore all the teeth off the front sprocket?

C'mon, man--- remember Sherlock Holmes. What has been "falsely eliminated" as a possible cause? It's right in front of us, I can smell it...

 

LEFT FIELD HUNCH!

HUMOR ME! Unplug the safety relay and take it for a ride.

 

opcorn

 

Milk Duds

 

Nahhh, I'd eat them too fast...


Maybe some sunflower seeds?

 

Have you checked the spark plug caps? Check inside for corrosion....I still believe that it somthing simple.

Kenneth

 

Re: Top end rebuild (Stuttering, Elec. Issues Prior) (Pic he

Grab a drink...

Since you all are here with your favorite munchies (I prefer Cracker Jack) and are ready for story time, I suppose that's it's only fitting to start from the beginning. Maybe recalling the PA trip from the point the XJ started acting ridonkulous will help me see what could have possibly gone wrong as well.

tl;dr, maybe. But I need to get this out of my brain and put it in words.

My brother and I left our hotel about an hour before the wedding started. It was only a 20-30 minute ride from Chambersburg to Gettysburg, but being unfamiliar with the area we wanted to be able to find the church with time to spare. As planned, we arrive at the church half-hour early, and at this point I am out of gas. Like no gas. Like switched to reserve three miles back out of gas. Since we knew where the church was, we decided to go on a hunt for a gas station before the wedding started. Ok, right here is the first time I noticed something different: When I started the XJ at the church, it wasn't that instant start and idle that usually occurs. It stumbled to a start, kind of bobbed a little, and then idled ok. It sounded way different, too. It wasn't that crisp clean sounding engine and exhaust, it was muffled and muddied, like the sound when your plugs are fouled. Hold your nose and go "wahhhhhhhhhhhhhhhhgnnnnnnn". That's what it sounds like, lol. Also there was no throttle response in neutral. It didn't rev real fast and come back to idle like a properly running engine does. It climbed slower, and it took a second or two for the RPM to come back down to idle.

So I'm thinking that all this has to do with the fact I has no gas, and I'm probably running on fumes. Or maybe Chacal was right and it is demon possessed since it started acting up while in a church parking lot. Anyways, I just need to find a gas station, and go from there. Turns out that Gettysburg, PA has no gas stations. None. If it did, we didn't find any because we rode up and down the city for 25 minutes and did not find one. That's science, kids. It was kind of frustrating because of that fact and knowing that I could run out of gas any second. With 5 minutes before the wedding starts, we head back to the church. Fast forward an hour, two people are married, they run through bubbles since no one throws rice because of exploding birds or some bulls**t like that. We get back on our bikes and try to find a gas station on the way to the reception. The XJ is still running the same. Crummy, no power, sounds sick. Three miles out of town we find a gas station, and not just any gas station, a pump first then pay no credit cards accepted gas station. It had the oldest ghetto pumps I had seen in a while. However, this fill up was such a relief. I would have paid that man $100 instead of $12 for that motion lotion and that feeling knowing I wasn't going to konque out on the side of the road in the middle of Gettysburg, where a canon ball gone awry from a mock war is about to fly across a hundred-acre misty field of grass and take me the F out.

The gas is paid for and I saddle myself up, hit the start button, and it does the same bobble of a depressing start like before. Same muddied sound coming out of the exhaust. Crap. We rode about 20 miles to the reception, and the XJ ran the same. Now I'm thinking that it could be the plugs, or the tank was so low that it sucked some rust particles through and into my carbs. No big, I'll investigate when we get back to the hotel. Fast forward two hours. Lots of dancing (none done by me, I just socialize with the other non-dancers), some champagne drinking, photo shoots, best man speeches. We say our goodbyes. My brother and I make out way down to our bikes still in our suits, put on some jeans and jackets over our suits, and begin the (from this geographical location) hour long ride back to Chambersburg. It's close to 1 am at this point. We are both tired and are only concentrating on getting back safely. The XJ is running kind of the same, no throttle response, same muddied exhaust sounds, except now it had developed an annoying vibration around 4.5K RPM. Needless to say we are wiped out when we get back to the hotel.

Too bright and early the next morning, I decide to try changing the spark plugs. It just so happens that I brought my tools, extra plugs, and a plug gapper. Aren't I smart? Actually, it was probably one of you who told me to do that lol. The new plugs are gapped and torqued in. I fire up the bike and the exact same thing. Throttle response like an 18-wheeler. The exhaust sounds like someone shoved a rag in both pipes. Still has that darn vibration when I rev it in neutral and hold it at 5K RPM. So about now, I'm thinking something happened with the carbs. An air jet or something got clogged because the plugs were black and sooty. Or maybe, just maybe the idle mixture screws vibrated out some? Nope, they were still where I had set them before the trip. Nothing I could check at that point would tell me what changed or how I could fix it. But the XJ still rode okay, didn't have any certain spots in the RPM where it cut out. I could make it 700 miles to home. Ahh home. This was one of those times you really miss home.

Fast forward three or four fill ups. We're somewhere in Virginia (I think). Lots of choppers, none of which had a rider that was wearing a helmet. Which really sucked, because you can't help but feel like a complete n00blet when they smirk at you for wearing protective gear. Oh well. We stay the night and the next morning, I pull the plugs and check them again. Black. Black and sooty. Black and sooty as the hearts of the chopper riders who smirk at you for wearing protective gear. Black and sooty as the brains of those chopper riders who smirk at you for wearing protective gear. Black and sooty as the faces of those chopper riders who smirk at you for wearing protective gear because the filth of the street flies up in their face all day. I wire brush the blackness and sootiness off the plugs, put them back in, and head to Advance Auto Parts which I had seen on the way in the day before. They're the only non-online place that I know of that carries the plugs I use, NGK CR8-E. While I'm there, I talk with the guy behind the counter for a little while. While he was talking, I spied some Seafoam around the corner. Maybe some Seafoam would help in some way if I put some in each fill up on the way back to Georgia.

Extremely too bright and early the next morning, the new gapped plugs go in, and so does a splash of Seafoam at the gas station. The XJ is running the same. We're cruising down the highway, and I can't get the XJ to go faster than 70. Wide open throttle, just 70mph. No coughing, stuttering, bogging of any kind, it just seemed to have a top speed of 70. Which really wasn't good, because it took a while to get there, too. And when you're trying to merge onto the highway and not get squished by the 10 18-wheelers that are flying up behind you at a hundred and ten, well, you'll go through some underwear. And we had just stopped for a refresher and I'm not about to delay our trip over some poopy underwear. At this point, the XJ develops a hesitation in acceleration. Where you give it gas real quick and it bogs for a half second, then starts accelerating. Running rich? Cranky diaphragms? Not sure which end of the spectrum I should be worried about. Can't do anything about it now.

Fast forward 200 miles. Lots of bugs on the visor, cool breezes, mountain passes, we are home in Georgia. Two days later, I go with a buddy to meet up with a buddy. He's riding a Honda CM400T, I'm on the Seca II. It's still running the same as before. After riding for about 30 minutes, it starts to get real slow and starts bogging on acceleration. Ok, now it's definitely time for some after trip investigation. The next day, I break down the carbs. Nothing out of the ordinary. Everything is still pretty clean, but I still give it the complete treatment. All passages and jets cleaned, diaphragms have no tears, they go clunk, float levels are all nominal while checked dry. The rack goes back on, new plugs go in. It fires up a lot faster than before, no stumbling to a start. Next I check the floats properly (as in, clear tube method, because no matter how much you want to argue, dry setting the floats is not proper) and they're all within spec although a little on the high side. But still within spec. It sounds better, idles better, but doesn't ride better. Still bogs down under a heavy load.

This is where I venture into the valves. A place I had not ventured before. I'm expecting the clearances to be horendous, because I had never messed with em, and I don't know if the PO had ever messed with them, and I don't know if the PO before him had ever messed with them, and for all I know they're the same shims that Mr. John Q. Yamaha put in the motor when it was built. To my surprise, there were only two valves out of spec, and even then, one shim off. Huh! After calling the five motorcycle repair shops in my area, I find out that they're all idiots who don't swap out shims. That's if the person I talked to knew what I was talking about. There was one fellow who said he's sell me one for $20. Did he have it in stock? Nope, he'd probably order from Bike Bandit and mark up the price five bucks. Well, I can do that. And I did. A week later, I have my two shims, pop them in, and fire the XJ up. Sounds a little better, only a little better, but still hesitated and bogged a little under acceleration. After a day or two of riding with this bog, it starts the stutter. As it's warming up, it stutters like the cylinders are fighting against each other at 4.5K + RPM. When it's all the way warmed up, it stutters under ANY acceleration.

At this point, I'm pretty sure that's when I made this thread. Start from page one if you want to get caught up lol.

Today, I did a good bit of riding/diagnosing on it. Got alot of good video with decent sound, so you can hear the stuttering. Unfortunately, my internet sucks a krayt dragon nut, and the video has been uploading the whole time I've been typing this. But it was the same today. Still. 5K RPM stutter, fully warmed up, unrideable. You cruise at 30mph, 3rd gear, 5K RPM, and give it some gas, it just feels and sounds like the engine is popping popcorn and you just lose speed, even while trying to accelerate. I don't think I've described it like that yet -- you lose speed while you're giving it gas and trying to accelerate like a motor gnome magically advanced the timing 30 degrees.

Safety relay -- for the sidestand switch? Must consult manual for location.

Yes, I replaced the coils and got new caps for all four.

Video finished uploading, now I can hit submit. This is probably the best audio I'm going to get. It's easier to hear the stuttering in the "chain angle" -- the "under bike" mount, not so much. But keep in mind, this is only the audio. When it stutters, it does it violently. You can't experience that with just watching the video.

[flash=560,349]http://www.youtube.com/v/Z3TyxuWpeDY.swf[/flash]

2:41 is the spot where you can hear the stutter in the exhaust the best

At 3:00 going up that hill, it almost didn't have enough power to get up there.

 

Very neat drive-chain cam............

 

I watched your video 3 times, and does sound like a miss, with popping from the exhaust, however, the "under bike" video almost sounds like something in the driveline....maybe I'm hearing road noise......I think your problem is still in the ignition system. I wish I was closer to ride the bike.

Kenneth

 

Same thing my bike does... atleast by the sound... and yes, grabbing your nose and going WAAGHHHHHHHHHHHHHHHHHHHHHHHHHHnnnnnn!!!! is a great equivalant to the sound it makes......

Great cam....


Unfortunately I can offer no help but am halfway through my bag of popcorn.... do I get a free refill since I bought a Large??

 

I should say same thing my bike does but for much shorter periods of time, and so far a wiggle of the spark plug wire... #1 on the left side, and it goes right away...

First time I noticed as well was the first time I got down to reserve...

Makes me wonder if the fuel pump is the issue.... sucking air when it's low or something..... I don't know but again....

opcorn

 

have you tried Bigfitz,s idea of unpluging the safety relay? Also, when you put the stock air filter back in, did you re-colour tune and re-sync the carbs?

 

I think your missing a Shim or a Thrust washer.

It seems like the NOISE accompanies the DRIVE CHAIN Vibrating excessively.
(Not running true. You can see the evidence of this near the END of the Video.)

Although the Drive Sprocket's Securing Nut is tight on the Shaft, ... an Alignment Shim or Thrust Washer appear to be:
Missing. (Needed; not present)
Extra. (Aftermarket Sprocket; Spacer~Shim -- Not deleted.
Backward. (Drive Sprocket shouldered for alignment. Installed backward?)

Some other issue causing the Chain to Vibrate rather than run true.
Warped Sprocket
Rear Sprocket not fully seated.
Rear Sprocket warped.
Rear Sprocket loose.
Worn Rear Wheel Bearings

Wrong Sprockets.

What-ever is the fault is causing the Drive Chain to Vibrate excessively on the run from the Rear Sprocket to the Drive Sprocket.

The Vibration is excessive.
Could lead to the Chain "Jumping" the Sprocket.

 

Have you checked? The video does seem to indicate that the driveline needs some attention.

However I don't think that's the problem.

I've been channeling Sherlock Holmes again.

We've thoroughly examined the fuel, intake and carburetors, and you've rebuilt the "air pump" (the top end of the motor.)

What HAVEN'T we thought of or discussed; at all?

........

the EXHAUST SYSTEM. Ever put a potato in an exhaust pipe (or have mud dauber wasps build a nest in your muffler?)

WHAT IF: The bike originally started running a bit "flat" because it was nearly out of gas.

BUT THEN, while you were in the church, somebody's unattended 3-year old very carefully and industriously filled your muffler (or mufflers) up with pebbles from the parking lot? I've raised five kids; and they've done it to me at least twice.

Did you have the mufflers off when doing the upper end rebuild?

If not pebbles, maybe you've had a baffle come loose or there's some sort of other obstruction in the exhaust system (like a wasp's nest?) Worth a look...

BUT

I still want to know what happens when you unplug the safety relay;

AND

You need to have a look at your front sprocket (although I don't believe it's related to your problem.)