Topic: New guy, need a lot of help.

[Stev-o]

.....it's like you guys know what I'm doing before I even tell you I'm doing it.

This ain't our first rodeo!

[Ace2cool]

ALL RIGHT! Rebuilt all 4 carburetors, inspected everything, those emulsion tubes were FILTHY, so good call on that. I just used a drill bit to tap it out of the carb. Set the floats to 22mm and barely touching the valve, and set the idle screws to 1.5 turns from bottom. Also bench balanced the carbs to 1/8" with the drill bit technique. Inspected all elements recommended by you guys, and everything checked out. Hooked everything back up, started it, and........

 Still not running right. Basically the same as before, but with less backfiring, because I'd suppose the mixture isn't so lean now that I'm running more "stock" carb settings. It also has NO power while under load now, lol. HOWEVER, I believe I've found the culprit, and I'm kind of embarrassed to not have noticed it until now. So I went and cleaned the contactors on the points last time I looked at it, and before I realized my feeler gauge only went down to .008, but I didn't make sure to see that they were lifting. Fail, I know. Attached is what I'm working with. Hit the starter, and sure enough, the left contactor isn't lifting at all. The right one is lifting enough to barely make clearance, but it looks like it could use a little more "up."

This is my first points ignition vehicle, so I don't really know where to go from here. Normally, I'd replace the distributor cap or the ignition coil, but like I said, I'm new to just about everything on this bike. Will new contact points help this issue? I sure hope it's a $16 fix, haha.

 I got good at carburetors, though. I "raced" the video that was posted of the guy tearing down a set of these carbs, and beat him through the teardown process. I spent about 30 minutes making sure every carb was spotless though, so it was more of an all day process. I used every bit of both cans of B-12. The salvage yard didn't have ANYTHING for this bike though. I was very disappointed by that. As far as exhaust, I may just go to a shop and see if I can add baffles to these mufflers and make it sound halfway decent. Exhaust is proving hard to find.

Oh, and Dimitri, I have a '94 300ZX 2+2 N/A, and a '91 300ZX TT. My other bike is an '05 GSX-R 600, and this makes vehicle number 4. I'm so glad TN doesn't have luxury tax like a lot of states I've been to, haha.

[Ace2cool]

Lol, forgot to add attachment.

But while I'm here, I'd like to go ahead and thank everyone for their TONS of help. This forum has impressed me more than most in the day and a half I've been a member. You guys truly love these bikes with your hearts, and that makes all the difference in the world. I have a feeling I'm gonna love it too, cause I have a big attachment to anything I took from a non-operational state and fixed. But seriously, a big KUDOS to this forum and its members from the new guy! 

[Ace2cool]

Nevermind, looked up a tutorial video on youtube, and figured out how to adjust it! It runs now! Pretty well, I might add!

How to adjust and restore points on your vintage motorcycle  That's the video I used, just for the record. Now all I need to do is adjust timing, get an airbox, and balance the carbs!

[Dimitri13]

What the hell >:| I was looking for a video like that a couple days ago and couldn't find ANYTHING. Mrmaxstorey (been a fan of his for ages and am subscribed) had it and it didn't show up in my search.

Ace, the timing is very easy to adjust, now that you know how to set the points gap. All you need is a timing light. A dwell meter is also highly recommended, but not necessary. A strobe gun is also helpful for checking the advance.

You definitely need to get a set of feeler gauges that go down to .001" or .0015". You'll need the .002 and .003" for setting the valves.

Have any pictures of the 300zx? It's a z32 right? Modified at all? Any dyno numbers?

[Ace2cool]

Yes, they're Z32's, the both of them. I love em. Here's an album from my flickr:

http://www.flickr.com/photos/aaronparris/sets/72157627337904650/

I was shooting a 1965 Minolta SRT-101 35mm camera, so that's why it's so grainy.

Here's a link to my photobucket. Got GSX-R Pics, TT pics, and N/A pics: http://s271.photobucket.com/albums/jj135/theaaronparris/



Ok, so now that it's idling half decent, I can start trying to set the timing correctly, figure out why it's not running right, set the mixture, then finally balance these carbs, right? Am I forgetting something?

EDIT: might as well post the latest and greatest symptoms:

Right now, it'll  free rev up to 4000-4500 pretty easy, but then kinda planes off and starts to sputter. Has no "go" in any gear, any throttle position, any speed, but especially tries to stall itself out in first gear taking off. (I think the front brake may be sticking at low speeds though. Gonna get some fresh fluid in there and inspect the piston.) I have to rev it pretty high and slip the clutch a couple times before I can let it out all the way. Also won't go over about 3000 while under load. Same thing happens as when you try to rev it: just sputters and planes off. If you start going uphill, it'll start to slow down and you'll have to downshift. Total lack of power.

Sounding like a timing issue?

[Dimitri13]

Have you checked the compression? You need to set the timing dead on (no need to get it running first, just with a timing light). Balance the carbs before you start messing with any screws.

Also I was going to ask if you track or auto-x the TT, but that answers my question

[Stev-o]

And you'll want to sync the carbs but will need the tool.

[cgswss]

I found these to be the best way to set valves

http://www.amazon.com/gp/product/B000UKITNU/ref=oh_details_o00_s00_i00

[lucky]

Well, the good news is, I'm not a total failure so far. I've got the float bowls disassembled, and everything seems to be in check there, albeit very dirty for having just been rebuilt and cleaned. Sludge in the bottom of the bowls, dirt caked on the floats, and most of the leaf springs were installed backwards from the way they're supposed to be keyed.

Thanks, I didn't know there was an FAQ section yet. I guess I broke my own pet peeve of any forum: posting without looking around and searching the site I'm already on. 

Ace2cool..... I have seen carbs that were filthy that worked perfect.

I have seen spotlessly clean polished carbs that were all!@#!$ up too.

What really matters are the facts.
Starting with new float needles and seats 90% of the battle.
Correct float height measured by the book.
Mixture screws all the same setting on multi cylinder engines.
Check the jet sizes,you never know what strange things have been done.
Same goes for slide needle settings.
Can you see daylight through the jets?
Slide heights all the same visually?
Do the slides all start to open at the same time?

[lucky]

In the video the person that made the video made many mistakes.

When points open is when the electrical charge is released.
When the points are closed is when the field is building up to be released to the coils.
LUCKY

People that make videos to show to millions of viewers should read from a book if they do not know how to explain it.

Get a workshop manual and read it!!!! Learn the right way.

Stop using incorrect and sloppy internet videos to learn important info.
If you wanted to be a doctor would you use the internet videos, or videos made by a medical group?

[lucky]

You can set the points with a multi meter on the
 ohms X 1000 scale with the key off more accurately than with a 12V bulb.


Analog meter is easier.
When these bikes were designed the digital meter
was just starting to be sold to the public.

[WhyNot2]

Get a workshop manual and read it!!!! Learn the right way.

Where would you get such a manual?

[Teatimetim]

http://www.amazon.com/Cb350-550Cc-1971-1978-Clymer-Motorcycle-Repair/dp/0892876530/ref=sr_1_3?ie=UTF8&qid=1345047972&sr=8-3&keywords=clymer+cb550

I believer there is a full service manual in pdf on her as well.

[Fritz]

I believer there is a full service manual in pdf on her as well.

There is a 'sticky' thread in this forum (SOHC/4 Bikes) which is always there to serve you, just one click away :

"*** Download Motorcycle Manuals ***"

[lucky]

Get a workshop manual and read it!!!! Learn the right way.

Where would you get such a manual?

Every manual has some mistakes , but I am using a Clymer's manual and it covers most everything. Ebay.

[WhyNot2]

Thanks man.............

[Ace2cool]

Ace2cool..... I have seen carbs that were filthy that worked perfect.

I have seen spotlessly clean polished carbs that were all!@#!$ up too.

What really matters are the facts.
Starting with new float needles and seats 90% of the battle. Check. I recieved the old hardware in the mail today, and verified everything was swapped out. These things couldn't have possibly even thought about running before this.
Correct float height measured by the book. 22mm, measured from the flange to the farthest point out with a digital slide caliper.
Mixture screws all the same setting on multi cylinder engines. 1.5 turns out from bottom.
Check the jet sizes,you never know what strange things have been done.
Same goes for slide needle settings. Everything checked out for sizes. Needle settings were 4 from the top.
Can you see daylight through the jets? I couldn't see through the idle jets at first, but it all came out easily. I'm thinking crap from the tank from where the P.O. used seafoam.
Slide heights all the same visually?
Do the slides all start to open at the same time? Yes, and yes.

[Fritz]

Hi Ace2cool

IMHO you shouldn't have pushed the needle jet tubes out with a drill bit but with a wooden stick. Too easy to nick the needle jet.

Did you make sure that the passages of the idle circuits were free by blowing compressed air through them? If these tiny orifices in the carb bodies are blocked, you'll never manage to adjust them.

Did you fix your ignition? To me your recent problems sound like ignition. A very weak battery could also cause your symptoms.

Cheers
Carsten

[Ace2cool]

I made sure to be very careful with the emulsion tube. Everything came out fine

So now, I have the timing set, gapped, ect, and it's exactly the same as before (though the timing was about a full centimeter from where it should have been.) I'm gonna take your advice and put the battery on the trickle charger and see what I can come up with. About to check compression. I'm worried about 1 & 2 because there's white smoke from the left side exhaust. I'm going out of town for a few days, though and won't be able to work on it.

EDIT: Forgot to add, checked the plugs. Not old at all, and black. Very black. Got some new ones, and I'm gonna gap em and put them in. I'm gonna have to get a compression tester that'll fot these spark plug holes though, cause regular testers are too big.

[Stilltime]

Subscribed...VERY helpful info for a new member/owner like myself.

Thanks!

Chris C.