1982 GS650E sputtering at steady speed

[gixerbike1]

Hey Guys,

I just finished restoring My GS650 and I have a couple of problems I'd like to see if you might have an answer for.

I did a thorough Cleaning of my carbs, DJ stage 3 jet kit / K&N filters and a Mac 4 into 1 exhaust.

I set the needle's at Position 3 as stated in the instructions with 160 mains, left the idle jets alone as stated in the instructions, 2.5 five turns out from bottom on the air screws, also as stated in the instructions.

I had to do the coil relay mod to get 12V to the coils and installed a new battery.

I also wire wheeled all of the ground strap ends, Battery terminal ends, bullet connectors (both male and female) and used all new stainless steel bolts.

Here's one of my problems: the bike wants to sputter at a steady state (4.5 to 5 k), it pulls strong and will do so to red line.

The second problem is that the bike wants to stop running when I pull to a stop.

In the yard it starts easy, idles fine, the choke works fine, I'm kinda at a loss as i'm no carb expert.

I like to clean the daylights outta stuff and the carbs are beautiful inside and out. and I installed a new Z1 petcock, Fuels a flowing.

I hope I've included all of the info you guys might need to speculate what the problem might be, if not ask me, please!!

Any idea's would be greatly appreciated.

Tommy

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. gixxerbike1,

Let me be among the first to give you a "Hee Haw Howdy!" and cordially welcome you to the forum.

It sounds like you've done a lot of good work already. Have you used a set of carb O-rings from http://cycleorings.com and completely disassembled and dipped your carbs? That is the recommended way of properly cleaning them. The procedure is in your "mega-welcome" below. A couple more questions: Are you using an inline fuel filter? Is the gas cap properly vented? If you hear a "pop" and an inrush of air when you open the tank, perhaps you need to clean the gas cap vents.

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[gixerbike1]

Carb cleaning

Carb cleaning

Hey there Mr. BassCliff,

Thanks for the warm welcome, I did forget some info, I thought so.

I did pull the carbs all the way down and separate 'em. Let 'em soak overnight, Each one individually.

I Rinsed them all out Really well with carb spray cleaner and I replaced all of the "o" rings in and on the carbs as well as the intake boots.

I used a rebuild kit on each carb, they all have new float bowl gaskets and i d set the float height to 23MM. The manual stated 22.4MM plus or minus 1MM.

Oh, how can i post pic's of my bike for you guys ??

 

[Big T]

Check the bottom of BassCliffs post for the link to his website

All knowledge, including picture posting, is included there


Just as a thought. I know Hammerhead had a similar problems with one of his bikes. He finally tore down the carbs again to find one of the needle circlips laying in the slide, and the needle doing whatever the heck it wanted to. So assembly may need to be verified, it happens to all of us, even someone as thorough as yourself

 

[BassCliff]

Hi,

A lot of aftermarket carb kits are inferior. You should be able to use all of the original parts and just replace the rubber bits, which can be had in kit form from http://cycleorings.com. Robert Barr is a member here and sells these kits really cheap out of love and respect for those of us who enjoy these classic bikes.

It has been mentioned numerous times here that setting the float height as closely as possible to factory spec works best. There's an O-ring on the needle valve seat that should be replaced. CLICK HERE to see the entire procedure.

I'm thinking a fuel starvation issue here, hence the suggestions above. But I must admit that I'm not a carb expert. Keep us informed.


Thank you for your indulgence,

BassCliff

 

[gixerbike1]

first attempt a Pic

first attempt a Pic

 

[gixerbike1]

carbs

carbs

Hey BassCliff,

Thanks for all the good info, I did indeed follow the carb info to the "T" when replacing the "O" rings, which i got from Robert, Thanks Robert for great "o" ring kits.

I did forget to answer one of your questions, I do have an inline fuel filter, should i remove it and just go with straight fuel line ?

Thanks,

Tommy

 

[BassCliff]

Hi,

Wow, great looking bike. Nice work. The 650E is not a common bike. Yours is a fine example.

Even when using a "gravity feed only" fuel filter, like one from a lawn mower, it could upset fuel delivery. As long as your tank is clean, the internal petcock screen should be enough. An automotive fuel filter will definitely cause fuel starvation because those require a fuel pump.

It seems you are up on all of our favorite maintenance techniques. I'm sorry if I sounded like a broken record. Many who visit here don't want to go through all the trouble to do it right the first time. Now that you've done all of that, we can fine tune. Keep us informed.

An afterthought....Did you closely inspect the slide diaphragms for minute tears or pinholes?

Thank you for your indulgence,

BassCliff

 

[gixerbike1]

Thanks Much BassCliff,

I've been working on it for about a year now, and it was ROUGH when i got it.

I did inspect the diaphragms and they looked good to me, when i push the slides up and let 'em drop they all seem to drop uniformly.

I'm going to remove that inline filter tomorrow and just go with straight fuel line since the fuel coming out of the tank is nice and clean. I'm going to sync the carbs tomorrow as well.

Thanks for all the help and input. I'll let you know what happens.

 

[Steve]

A few suggestions, since you have asked for them.

1. Lose the inline filter. If your tank has been cleaned, there is already a filter on the petcock inlet that should catch any crud. Just in case anything does slip by, there should be another filter on the top of the inlet valve of each carb. No real need for a third filter.

2. Your 23mm float height is on the lean side of tolerance. You have to remember that a larger number when setting it is actually putting the float farther from the valve, which lowers the fuel level when you turn the carbs back over for installation. A single millimeter does not sound like much, but set the floats between the 21.4 and 22.4 marks. Be sure to check both sides of the float. If one side is bent a bit, it might shut off the fuel flow even sooner than your realize.

3. Adjust what you are calling "air screws". They are actually "idle mixture adjustment screws", as they control how much of a pre-set mixture is admitted into the air flow at idle and low throttle openings. On a stock bike we usually recommend between 2.5 and 3 turns out from lightly seated, your slightly modified bike might need 3 to 3.5 turns. Also be sure that you are using full 360-degree turns. I have seen more than once where someone has counted 'flips' of the screwdriver as a 'turn', so they only had half the amount they thought they did.

Other than that, enjoy your relatively rare ride. It looks great. :clap:

.

 

[gixerbike1]

Still have problems

Still have problems

Thanks Steve,

Well, I did a sync on the carbs, Removed the inline filter and took her out for a spin. She didn't run well at all and would cut off every time I came to a stop.

I went back to the house and removed the tops of the carbs and moved the "E" clip on the needles up one notch,moved the Air screws out to 3.5 turns, put everything back together and took her out again.

She still sputters and pops in the low rpm range 1/3 throttle just going through the gears easy. WOT is great.

Once i got on the interstate i got down on it and it pulls like a demon and it will now hold steady without a problem at 60 to 65 mph, purred like a kitten, this was around 5k.

I took my exit off of 64 onto staples mill road and it died again at the light. It fires right up and idles, it just has this weird problem coming to a stop and anything below 5k.

I pulled the plugs when i went home and they were black as the ace of spades, full of soot.

I'm at a loss, the Idle air screws are 4 full turns out from lightly seated, I have 12V at the coils, which are new, along with new wires and new plugs.

I installed the coils,wires and plugs today at a friends suggestion after seeing the filthy plugs.

Any other idea's as to why this thing is acting like this ? I'm beating my head against a wall on this one.

Thanks for all your advise so far.

Tommy

 

[twr1776]

From the picture you posted it looks like you have a K&N air filter in the stock airbox. If so the DJ stage 3 kit is way rich, I think it is normally used for the individual pod type filters with a header. The stock airbox & Mac header usually calls for a the stage 1 kit as I recall.

 

[gixerbike1]

K&n

K&n

I have the two K&N filters that feed all four carbs. The airbox has been removed and i have a full MAC 4 into 1 exhaust.

That's what has me stumped I'd have thought it would be too lean not too rich.

Thanks

 

[Big T]

Your basic thought is correct - pipe + pods = lean

The jets are too big and/or you over oiled the filters to make it that rich

Did your DJ kit have smaller jets?

 

[gixerbike1]

155's on the way

155's on the way

Big T, I sure do. The kit came with 155's and 160's. I can go to the 155's as i'm going to pull the carbs off the Bike again.

It was also advised by a friend of mine to go back to the stock needles to see if that helped any.

I didn't think the main jets would affect low rpm and idle, But I've got little else to go on and i do have the smaller jets and the stock needles.

Any other thoughts before i give this a try ?

Thanks guys.

Tommy

 

[twr1776]

You probably have already done this but have you checked your valve clearances?

Do a search for chop test and you will find some very good info. I am not a carb expert so anyone can correct me if needed but I am pretty sure the order usually goes like this, adjust valves, chop test at full throttle for the main & adjust jet size as needed, chop test for midrange and adjust needle height as needed, chop test for low range and adjust pilot jet size as needed.

 

[gixerbike1]

Valve's checked

Valve's checked

twr1776,

I did indeed check the Valve clearances and all were good, I did that before the carbs, this thing is strange i tell ya.

 

[waterman]

I am surprised that Dynajets are 155 and 160 for a 650. Stock the E model uses a 97.5 for main jet, the g models are richer at 110. I know there is a difference between Mikuni and Dyna but it isn't that extreme is it? Just asking for my curiousity :-k

I was also under the impression that the Mac 4 into 1 isn't the high performance free flowing exhaust like a V & H or Supertrapp designs and didn't need as much radical tuning to get to run correctly. I know there isn't a lot of discussion about 4 into 1 tuning for the 650 since there aren't too many here whom have undertaken this task.

Short of doing a few plug chops, I don't have any advice to give, but wish you the best of luck and please report back what works for you.

 

[BassCliff]

Hi,

Here are a couple of informational links that I've collected on my website. They might be interesting to you...


For CV Carb jetting, see the very informative article at Factory Pro. Also see the carb jetting tips at Motorcyclecarbs.com, Inc.


Thank you for your indulgence,

BassCliff

 

[Big T]

Tommy

The 155s will probably be too large also

I don't have a 650, but I'd think you'd be more like 125-135 Mikuni size (I forget what the DJ size factor is)