New (to me) Seca-- some questions

I saw the people were wondering about the $500 Seca on Philadelphia Craigslist. Well, it's mine now. I think it could be a good bike, but it's ugly and abused. I put about 40 miles on it today and found few problems.

Weird electrical problems-- I think I can figure these out.
Tach died-- probably can figure this out.

Clutch slips-- not badly, only if I give it a good deal of gas at low revs. Am I just asking too much? Doesn't seem like a big issue, I'm just not sure whether it's normal or not.

Pops out of first-- not too often, but when I went through a parking garage it happened about once per floor. What might this be?

The bike claims to have 26,000 miles, but who knows...

Thanks-- I'm so glad I found this forum.

 

A big welcome to you Adrian, good score on that Seca. Glad to see it went to an appreciative person.
Tach- probably a bad contact, clean and repair as needed.
Clutch- It is dying, time to replace. This condition will also manifest itself in your first gear issues, though other conditions may be present. Do the clutch change and road test.
Hope this is what you needed to hear. Be sure to post the results of your clutch job.

 

Welcome Adrian,
Robert is right, that clutch thing is not that big...
check out this link for replacement discs. http://cgi.ebay.com/ebaymotors/Yamaha-C ... enameZWDVW

I dont know if they are real good in quality but the price is right.

I had tach trouble too and was going to buy another but to my surprise it just started working and I haven't had a bit of trouble with it since!?

$500.00 sounds like the perfect price for a good fixerupper

Good Luck
Mike

 

If that bike has a cable tach - make sure the fittings are tight into the engine and as the tach itself. My tach was doing strange things the other day and it turned out to be a loose fitting at the engine. Tightened it up and it's been fine since.

If you don't want to replace the clutch, you could try to play around with the clutch adjustment. If you were or PO was screwing with it, it just may need adjusting. Temporary fix but it may help.

Rob

 

I'd double check the cable adjustments and lever before changing clutch.

On mine there is very little adjustment difference between slipping and won't disengage with lever pulled.

Of course PO put the wrong lever on and I believe it hits the grip too soon because of the shape.

 

Well, the tach was just a loose cable, and the electrical stuff was all due to a melted headlight connector. So that was easy.

The clutch I'm not too worried about yet. I adjusted it so the lever has just a little play and the cable feels just a little loose. No change.

The big problem is first gear. Is there any possibility that this is a simple problem that can be fixed without cracking the case? Because that's not gonna happen. I can't find any real pattern to it, except that it happens more when it's warm. I wouldn't say that it has a lot to do with revs or load though. Not sure.

The other big problem is racing idlw when it warms up. I can feel the heat from the heads and it pops like it might be backfiring, so I assume this is lean mixture due to the fact that it probably leaks everywhere. I guess I have to try to replace some things, but I'm not sure when I can. The big problem is that I bought it for daily commuting, so I just want to ride it, not work on it. Yeah, I know, I know... But I didn't have money for a better condition bike and I only have to go about 5 miles.

 

If it pops through the carb then it is probably a lean mixture. If poping out the exhaust then most likely a rich cylinder. A colortune followed by vacuum sync are the first things I would do other than checking the airboots and intakes for a good seal.

 

Not that I think this is going to cure your problem of popping out of 1st gear ... but, why not -- for the heck of it -- adjust the shifter lever height so you get a good movement upon making changes.

There ought to be a "Turnbuckle-type" adjustment that you can tweak; allowing you to get a little more throw when you shift.

Like I said ... this is no cure for a bent shifting fork ... but, it might get you a little momentum when making the changes that might help a tiny bit.

It's one of those ... "See if this helps it any" suggestions. It's a 50/50 shot.
Either it helps a smidge or nothing changes. Just something else to try before throwing your hands up and surrendering to it being what it probably is.

It's something to try that don't cost anything ... look at it that way!

 

Thanks for the suggestions-- I've got some new problems now, though. The really nbearable problem was the racing idle. I had read that this was probably due to leaky boots. So I took off the carbs and has a look at the boots. They were realtively good except for #4. That one had big tears in it and someone had tried to patch it with RTV. Now, the only thing I know of that will easily remove RTV is gasoline... So I patched it up with some gasoline-resistant gasket stuff.

Now it won't start. Took me a good hour to get it running. I took it for a ride, and the idle never raced, but I could never take the choke off either. So seems like its lean... Except when I try to start it I can smell gas and it starts best with just the smallest bit of choke. So is it lean or rich?

I guess I need a colortune, but this seems weird. I must have done SOMETHING to it, but I can't think what.

Then it occured to me that maybe the previous owner had put the idle really low. I turned it way up, and it still won't start. Tried starting fluid (actually, couldn't find mine, so it was brake cleaner) and it fired right up.

I'm trying to think of what I changed that made it hard to start and I can't make sense of it. Before, it would fire right up on the first try every time. But it ran horribly warm.

The other thing is that before I startes messing with it, the boots from the airbox to the carbs were disconnected on both ends... just sort of sitting in there. I got them connected to the airbox, but the clamps on them don't do a thing, so they're still loose. Also, previously air was shooting right past the filter. Now its not.

As far as first, I looked at the shifter and didn't see how adjusting the turnbuckle could help, but I will look a little more critically.

 

Air. Fuel. Spark.

You made a change. Think about it! You reduced the amount of air to the mixture when you plugged-up the leak.

Until you can get yourself Colortuned ... just do this.

Adjust the four Pilot Screws in ... very carefully ... until you "Bottom them out."

Then, turn each one OUT -- two and three-quarter -- turns. This is just a skootch over Factory Preset. Start it. Run it until it warms-up.

See how it idles and runs like this ... if it's OK ... leave it. It might be a tad rich. But, a tad rich is a whole damn site better than being a tad lean.

Give it hell ... Have fun doing it. You can't mess-up.
Wait ... you CAN mess-up. If the screws are frozen -- DON'T DO ANYTHING until you let us know they are seized.

Let us know.

 

After fixing your air leak, sounds like all you need is a good carb tune up.

Hard starting is often just mismatched carb setting. If the engine doesn't get an even flow of fuel from each carb then they can be a pig to start.

Picture two rich carbs and two lean carbs in the same set. Crank it over and two plugs get too wet to spark and the other two are not getting enough fuel to fire. That's usually why easy start works as it is providing a combustible mixture. Once the engine fires vacuum works better at dragging fuel from the carbs.

At cranking revs there is very little vacuum to draw fuel/air from the carbs so they need to be spot on.

I would look at removing the carbs and bench syncing them as well as setting the mixture screws to two and a quarter turns out.

It is a good starting place in the absence of the correct tools.

Remember the PO has prolly had a tinker with the carbs trying to get it to run right with that air leak.

 

This makes sense, I think-- What I couldn't figure out was that I had eliminated some extra air... But it still needed choke when warm... So that made me think it was still lean. But it seems rich when trying to start.

But one boot was terrible and a second one was iffy. So maybe the PO had made those two carbs richer to compensate. Hmmm...

 

CSI Philly

You're on the case.

Stick with us, bro ... and when the weather gets too cold and crappy to ride ... we'll have you splitting the cases and puttin'-in some new forks!

 

Welcome to the site!
Whenever I remove my carbs and drain for whatever reason the reinstall, it takes a while for the bike to fire up.
What I do is pull the plugs and drop a slight amount of fuel in the chambers then she fires right up. After that, she fires right up without a hitch whenever I start.
Probably has something to do with priming the carbs to get the fuel to the correct operating level. BTW- I do put the petcock in "Prime" for this procedure then back to run when things are a go.
Since the carbs affect operation so much, I too recommend that you clean those suckers out. You'll be happy you took the time to do it.
Have fun with it.

 

OK, did you by any chance turn the carbs upside down when you had them off?

If you did maybe a float got hung up!?
You can try tapping on the carb float bowls and see if the float will pop loose, and I hope it does

These guys know their stuff on these carbs and I dont doubt that they are right on with lots of their advise. those carbs are no doubt way out because of the tears in that #4 boot.


Somehow I can't get it out of my head that you should try an oil change before you give up on those clutches. (just a gut thing you know)
Maybe the PO used some kind of additive that is causing them to slip?

 

Very true. PO's will do strange things when unloading a bike.

The PO might have topped-off the oil level with who-know's-what before you picked it up.

Adrian ...

Fill-out your signature portion with all the info on your bike. It's going to help us help you.

Year - Model - YICS? - Miles (add this info to your signature section for awhile, please.

 

Well... no progress. Rode it today with new plugs. #3 looked reasonable. 2 and 4 look lean 1 looks lean and rich at the same time. The electrode was white, but the body was sooty.

In the morning, I let it warm up for quite awhile, and it ran fine, but I couldn't take the choke off.

In the evening, it was a bear-- it bogged down trying to accelerate from a stop.

SO when I got home, I screwed in all the mixture screws and loosened them 2 and 3/4 turns. It was nice and warm, but still woudn't run without the choke. Finally ran with no choke at 5 1/4 turns, but I had to raise the idle. Went for a ride and it was a disaster. Still bogged down, but I had raised the idle so much that I couldn't use the choke. So I feel like it's still lean.

The only other thing I can think of is that maybe it's close to being right, but it's hesitating because of weak spark.

I just can't figure out why it was doing so well (relatively) before I fixed the boots.

Oh, and I think it is no YICS.

 

You didn't happen to mention what condition the air cleaner is in. When you reconnected the boots to the air box that changed a couple of things. Air to fuel ratio being the buggest one. Hopefully you dont find a mouse nest in there. LOL. I would definately agree with everyon else here a carb cleaning and tune is in order and she ought to run great for you. Why is the bike a SHE. I shouldn't have to state the obvious. Good luck and keep us informed.

 

The filter was a nice clean K&N... But the gasket was allowing all kinds of crap past. Seriously, the filter looked barnd-new claen, but there were bugs and stuff sitting in it on the clean side.