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Bryer
03-02-2010, 04:45 PM
Hello,

So as some of you may remember, I was looking at an 96 750 that was not running...

Well I got it running, for the most part. After cleaning the gelled gas from the carbs, installing new plugs, and cleaning out the carbs a second time, I got the bike to where it will start up immediately without any choke.

The problem starts when I go to give it throttle. As soon as it is applied, the engine bogs down, and then stalls. If I apply choke and give it throttle, it will not stall out (the rpms will be around 3-4k with a little choke), but will still bog down. And it will do this with the petcock in all three positions.

It has a K&N at the moment. I've ordered an OEM air filter it should be here in a few days.

Any ideas what the problem could be?

rexazz2
03-02-2010, 05:35 PM
are you giving it a couple minute to warm up ?
after three or so minutes you should be able to turn off the choke and be good to go

Kreylyn
03-02-2010, 05:39 PM
So the idle circuit seems decent, but the main fuel flow (main jets, diaphrams, needle jets) don't seem right atm. Either something isn't set up right, of they are still dirty?

Have you done a sync btw?

Krey

Philskat
03-02-2010, 05:43 PM
mine did that and it ended up being the the orings in the carb boots. Start it up and spray aroung the boots where they bolt to the head with some carb cleaner or something similar and see if the idle smooths out or if u can rev it if so then there is the problem.

loudnlow7484
03-02-2010, 05:56 PM
take the airbox off and watch the slides. When you give it a little gas, do they rise up? Sounds like dirty main jets, or binding slides to me.

Kreylyn
03-02-2010, 06:09 PM
Easy way to test the slides with a can of air.

YouTube- Slide works

Krey

kevin2502000
03-02-2010, 07:48 PM
You can put your mouth on the same place and get the same result. That is a great way to make sure your diaphragm is sealed and not leaking.

Kreylyn
03-02-2010, 07:50 PM
You can put your mouth on the same place and get the same result. That is a great way to make sure your diaphragm is sealed and not leaking.

There are some places one's mouth just does not belong... :smt011

Krey

overboost07
03-02-2010, 07:53 PM
There are some places one's mouth just does not belong... :smt011

Krey

you said it before i could :tearslol

kevin2502000
03-02-2010, 07:58 PM
Well considering I clean them with hot soapy water plus steam cleaning before I put my mouth on it, does that make ya fell any better?? I'm sure my mouth has been on dirtier holes..................

Bryer
03-02-2010, 08:00 PM
Have you done a sync btw?

Krey


When I put everything back together, I did a visual sync. Today I just built a sync tool, but due to the weather have not been able to do much. I also did not know if the incoming air filter would change things once installed.

Tomorrow if weather permits, I will pull the airbox and check the slides, and the o-rings like Philskat suggests.

I forgot to mention, when I put it back together the second time, I was able to take it out for a 5 minute joy ride. It performed wonderfully, except for the rough idle (had not sync'd), until it stalled out on me while entering a corner. Since then it has reverted to this.

Another quick question, how am I supposed to get the vacuum covers off the nipples to do the sync with the carbs on the bike? My stubby fingers aren't going to fit in there!

Sorry if I am giving you guys too much useless info here... I used to be in Tech Support and hated when people would ask for help and just say "My computer is not turning on" without giving any more info.

Kreylyn
03-02-2010, 09:10 PM
Well considering I clean them with hot soapy water plus steam cleaning before I put my mouth on it, does that make ya fell any better?? I'm sure my mouth has been on dirtier holes..................

I feel dirty now... and want minds eye bleach! :smt012



Another quick question, how am I supposed to get the vacuum covers off the nipples to do the sync with the carbs on the bike? My stubby fingers aren't going to fit in there!

Sounds like your headed down the right path on the other aspects. I suggest using 4 short pieces of vacuum tubing on the sync ports... and plug them off. Then, when time to sync... you plug your sync tool into the tubes... that are not sticking about 1" above the carbs. :bigthumb

You may have to remove the carbs to get those tubes on if your fingers are too stubby or fat. 8-[

Krey

paul.miner
03-02-2010, 09:17 PM
Easy way to test the slides with a can of air.

YouTube- Slide works (http://www.youtube.com/watch?v=Q5BGTi6OX1E)

Krey

That's pretty cool!

Bryer
03-03-2010, 02:42 PM
Alrighty, here's the skinny...

I turned the bike on without the airbox, and when I gave it a little throttle, all four sliders shook, but did not go up. I have a can of air, but I cannot figure out where to spray it to make mine behave the same way as in the video.

With the bike off, I manually raised each one of them. One and three went up all the way, two and four, however only raised about 3/4 of the way then i met resistance. Problem?

Edit: I reseated the springs in those two slides, and now they are moving freely. I am still getting the bogging down and stalling though. To see if it would make any difference, I placed my hand over the intake hole, without covering it all the way, and was able to rev the bike without it stalling. This to me says it is the filter, yes?

kevin2502000
03-03-2010, 03:24 PM
You need the airbox on for it to run correctly. So yes, put the airbox and filter back on.

Bryer
03-03-2010, 03:28 PM
When I placed my hand over the intake hole it was back together. I guess I am just going to have to wait a few more days until my OEM filter arrives.

Thanks for all your help guys.

kevin2502000
03-03-2010, 09:17 PM
http://katriders.com/vb/showthread.php?t=99740

Bryer
03-08-2010, 09:50 PM
Ok, so I got the new OEM air filter installed today, pulled apart the carbs again still clean as far as I can tell, but for good measure used another can of carb cleaner on all the parts. After that did not work I pulled the fuel filter (clean) and pulled the petcock (screen clean). I tried running the bike without the fuel filter, still no improvement.

I am at a complete loss here... any new ideas?

kevin2502000
03-08-2010, 09:58 PM
If it runs better when you partially cover the air filter opening then it is running way to lean.

Kreylyn
03-08-2010, 10:18 PM
Have you removed the carbs, pulled the pilot jets out of the carbs, and soaked the carbs in a carb cleaning dip for 12+ hours?

Or are you just opening the caps and spraying cleaner for a moment and moving on?

Krey

Bryer
03-08-2010, 10:34 PM
This time I pulled it apart and soaked them for 5-6 hours, last time was 24 hours.

I do have a question... On the bikebandits schematics, for the carbs, there is a small o ring that sits on the topside underneath the black caps. What is that for? It is number 45 on the carb diagram...


In reference to Kevin, I thought when you covered part of the filter opening and it ran better, that meant that you were running too rich to begin with? I don't have access to the angled screwdriver to adjust the A/F screws with the carbs on the bike, so I have to remove them to change the settings. With the stock air filter, and a full Yoshi exhaust, what should the A/F screws be set at?

MickM
03-08-2010, 11:19 PM
Hi;
I could not find part number 45.
Do you mean part number 16?

That is to let engine vacuum suck against the spring below the diaphragm.
If it is missing or cracked then there will be a leak and the plunger will not rise for that carb.

The spring pushes down, the vacuum sucks up.

When you restrict the airflow you reduce the air going in.
This richens the A/F ratio. (same amount of fuel but less air = richer).

Mick M.

Bryer
03-09-2010, 12:24 AM
Dyslexia strikes again! I get it now. I had it backwards... Guess I will try to adjust the A/F screws out tomorrow to see if that helps.

Number 45 is on the topside of the carb. Right above the vacuum nipple.

MickM
03-09-2010, 02:40 AM
Hi;
I still cannot find number 45.

http://suzuki.dgy.com/fiche_section_detail.asp?section=96605&category=Motorcycles&make=SUZUKI&year=1989&fveh=2165

only goes to 39

http://fiche.ronayers.com/Index.cfm/Module/Main/TypeID/26/Type/Motorcycle/MakeID/2/Make/Suzuki/YearID/36/Year/1995/ModelID/6554/Model/GSX750F_KATANA/GroupID/275604/Group/CARBURETOR

only goes to 44.

You have a 96 750 right?

Mick M

TRH1
03-09-2010, 08:38 AM
Have you checked the float height on all carburettors? This is important as it governs how rich/lean your mixture is.

Bryer
03-09-2010, 01:16 PM
It is an 06 750. Ah that would explain it. We were looking at different schematics. Number 16 on the ones you posted is 45 on bikebandits... Yes, those are the little orings I am talking about.

I am beginning to think those might be contributing to my problem. They are looking really rough. Time to order some more parts.

Edit: No, i have not checked the float heights, it did not even occur to me. Are there any easy ways of doing this without a caliper?

kevin2502000
03-09-2010, 09:11 PM
You can buy a cheap ruler that has metric and cut a notecard to the height you need. Float ht. is VERY VERY import. Click my signature link.

Hegmann1391
03-13-2010, 06:46 AM
Easy way to test the slides with a can of air.

YouTube- Slide works (http://www.youtube.com/watch?v=Q5BGTi6OX1E)

Krey


So what should be looked at if your carbs don't do that? I pulled mine off this morning to clean them sometime and I tried it and only two of my carbs moved at all.

Kreylyn
03-13-2010, 08:10 AM
So what should be looked at if your carbs don't do that? I pulled mine off this morning to clean them sometime and I tried it and only two of my carbs moved at all.

Clean them first, very well.

Check the slides to make sure they are clean, and will slide easily.

Check the diaphrams to make sure they are soft, pliable, and do not have any holes.

Check the springs were seated properly.

Check the diaphrams are seated properly so that it seals when the cap is put on.

Check that the oring on the vacuum port is in place.

Check the sync port covers are sealing, and not allowing a leak.

Krey

hardlydangerous
03-13-2010, 10:05 AM
look
if your not removing the slides, emulsion tubes, pilot screws, main jets, enricher valves etc etc when cleaning the carbs, you are not cleaning them at all.
the carbs have to be stripped down. set aside all the pieces for each carb in their own container so you dont mix them up then properly clean the carbs.
you can clean them 100 times but if you dont do it properly its still not going to run right.