Author Topic: Me Again (Read 3685 times)

Sierra2 · « **on:** March 26, 2006, 08:03:04 PM »

OK all....back again. I know I'm supposed to look through the site to find existing threads....but man it's frustrating trying to find the answer you're looking for.

So here's my problem.....Recap....You guys helped beyond belief in re-assembling my carbs after a winter of restoration. (Thanks again.)

Warm weather's coming now. My new problem is that she fires up and runs a little high with the choke on. The instant I put any throttle to it she calves, sputters and dies. Fire it back up again no throttle....and she runs fine. Even if I let her warm up for a while she'll run for 5 - 10 minutes with the choke on......again instant death when I give the least amount of throttle.

Where do I start???

Pete

gsxr400 racer · « **Reply #1 on:** March 26, 2006, 08:07:59 PM »

plugs

PitterB4 · « **Reply #2 on:** March 26, 2006, 08:12:46 PM »

Refresh our memories... what perf mods if any? Where are your a/f screws? This is a total guess but if your plugs are in good shape, I'd try backing your screws out a little.

Sierra2 · « **Reply #3 on:** March 26, 2006, 08:15:22 PM »

As a part of my restoration I put in new plugs, and changed the wires....they've been in for a month and I've started her about a dozen times.....Can you be more specific about the plugs........do I need to look at them to determine if it is running to hot/cold lean/rich or are they just done (again)?

Pete

gsxr400 racer · « **Reply #4 on:** March 26, 2006, 08:22:37 PM »

if they are rich then you more than likely got oring issues or are running the choke to long!

Sierra2 · « **Reply #5 on:** March 26, 2006, 08:33:37 PM »

Sorry, Ive had a VERY frustrating day

In late December I found you guys and dove into a restoration project of my 91 bandit. She sat for a year in a wet garage. So wet that when I took her of the board the centre stand was on she sank up to the axles in the gravel floor. When I started taking her apart I was heart broken. The carbs were green with corrosion. My airbox was a condo for a family of mice, and my vaccum tube was plugged with some kind of insect carcass.

The long and short of it was that I recieved some very sage advise through the cleaning process, and re-assembly. I then changed the plugs and wires, and she sparked to life sometime in the end of January. Quite pleased with myself I left well enough alone. Now I realize that I touch the throttle and she dies. I didn't touch any of the adjustments on the carbs. I did pull them apart to clean them, but managed to reassemble them without changing any of the screw settings. I have a Canadian bike, and took a suggstion to move the needle valve up one notch to try and reduce the flat spot she had (when she was running!!) I have since gone back in and reset them to the factory setting ( thinking that might cure it) No luck. It is doing exactly the same thing. The exhaust is heavy and a bit blue until she warms up....I touch the throttle she dies. The weather here has been very humid as spring arrives, maybe the dampness has affected my new plug wires??? Or did I just F%#$ everything up when I put it back together.

I don't know....I would be grateful for any suggestions.

Thanks

Pete

Sierra2 · « **Reply #6 on:** March 26, 2006, 08:36:20 PM »

I should include that she's completely stock, and had one owner....me.

Pete

BrianM · « **Reply #7 on:** March 26, 2006, 08:46:46 PM »

Following Occams Razor, I'd tend to look at the fuel first. What you're describing sounds Exactly like water in the carbs. Just enough gas on top to support an idle, but crack the throttle and it sucks up water. Drain the float bowls into a glass jar and look for some water seperation.

Also, pull the plugs and just see what they look like (doesn't look as if you said that had been done) ~ once fouled, they will be Much more prone to failure. Cleaning will resolve that well enough that a good running bike won't have an issue (though it's been a problem on more than 1 poorly running bike I've worked on).

Sierra2 · « **Reply #8 on:** March 26, 2006, 08:51:52 PM »

Thank you Brian, I'll give it a go. Any way to save the brand new plugs if they are indeed fouled....I don't like throwng away $75.00.

Pete

Thief400 · « **Reply #9 on:** March 26, 2006, 09:04:00 PM »

I would make sure you have the carbs pushed all the way back into the intake spigots. Sounds like you have an air leak. They are tricky to get in sometimes, you can spay a little wb40 on the boots to help.

BrianM · « **Reply #10 on:** March 26, 2006, 09:09:58 PM »

Quote from: "Sierra2"

Thank you Brian, I'll give it a go. Any way to save the brand new plugs if they are indeed fouled....I don't like throwng away $75.00.

Pete

No reason to toss them (well, not for a few thousand more miles/KM) ~ just make sure they're not Completely fouled up. If they are, clean them off as best you can and put them back in (paying careful attention to the torque... the first time you get the crush washer, but that's used up now).

gsxr400 racer · « **Reply #11 on:** March 26, 2006, 09:51:41 PM »

not a problem bro, lets get this straight it starts up with choke right?
shut off choke it idles?
with choke off you give it gas it dies?

Racerruss-ducati · « **Reply #12 on:** March 26, 2006, 09:54:21 PM »

Starting from the simplist and working back, did you put the airbox back on it with a foam filter? These bikes will not take the throttle without the air filter (short of some major rejetting).

Assuming you knew how to rebuild the carbs and got all of the seals and orings back in correctly, this sounds like a lean fuel condition (like the others said, water in carbs, air leaks, still plugged fuel passages, etc). These carbs have the smallest holes I have ever seen in a set of carbs and they are notorius for getting clogged by the particles slightly smaller than nothing.

If your bike was sitting for a while, it is likely the tank has some rust as well. Be sure to get an aftermarket inline fuel filter to make sure the fuel is clean to the carbs, otherwise, you will wear out the screws cleaning the carbs.

GSXR400 Racer has offered to help out someone else in the forum out by rebuilding their carbs for a nominal fee. Probably would be money well spent given his experience with these motors.

Good luck and keep us posted, carb information is always worth posting.

Sierra2 · « **Reply #13 on:** March 26, 2006, 10:13:01 PM »

Thanks all!!

Racerruss - yes I have the foam filter back in...cleaned and lightly oiled. No fuel filter YET....that will be my next purchase. I was surprized to see very few problems inside the tank. Could be crappy gas though, I have since the rebuild put a bit of mediocre fuel just to get it running...stuff I wouldn't be shy to throw out. Thanks for the offer to send them off, but I'd like to try and solve this myself first (maybe learn a little at the same time - like patience!!)

GSXR 400racer - yeah she'll run with the choke on for as long as I leave it on. I can't turn it right off to zero or it will stall. But I turn it right down and touch the throttle, and it's like I threw the kill switch.

Thief - thanks that's the advise you gave me the last time....and you were right before...this time they're on!!

I'll try the fuel bit, but I'm leaning towards the fouled plugs....or maybe a screw setting??

I know... I know.. start simple first.....Thanks.

Pete

gsxr400 racer · « **Reply #14 on:** March 26, 2006, 11:35:45 PM »

Okay after all that , check the plugs first, if they are fine sounds like carb clean again or bad gas some times you can drain the float bowls with the screw empty tank put frash gas in and that fixes it usually. unless you have bad orings