1982 GS650E sputtering at steady speed

[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

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

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)

[gixerbike1]

Jets and More Jets, and some other stuff too

Hey T,

Yeah, I have a friend that's the parts manager at the local Honda house, I'm going to swing by there on the way home and pick up some 130's.

I'm going to pull the carbs back down, replace the float needles and seats for stock units from Babbitts, re-adjust the float height, re-bench sync the carbs and go to the 130 mains to see what that yields.

Wish me Luck

[drejal]

please keep us posted!

I'm following your thread because of a similar problem on my 550. I haven't been able to run it for a few weeks, been waiting on this and that (parts, painting), but I have a feeling my p.o. went too large on the mains also.

Thanks!

AA

[gixerbike1]

still sooting up the plugs

drejal,

Well Honda House didn't have 4 of any jets in sizes i wanted. I went home tonight and pulled the carbs back down again.

I made sure the float height on all 4 carbs was right at 22MM.

I redid the bench sync, and the bike tends to idle a bit smoother.

I changed out the main jets (160) from the jet kit for the 110's that were in the bike when i got it.

I set the idle air screws to 4 turns out. it's still running really rich and when I blip the throttle it idles up and hangs for a few seconds (around 2K) and then returns to idle.

This is really strange, from what i read in the info BassCliff gave me it states that when the idle hangs like that it's an indication of being lean

I'm running the stock D8EA's, i might try D7EA's for the heck of it.

Any other idea's Guys ? I might be getting rid of this thing if i can't get it right.

[gixerbike1]

doing much better

Well guys,

I think I'm closing in on it. I replaced the plugs with CR7EA's, set the idle air screws to 2 turns out and set the idle.

Now she idles fine, when i blip the throttle, it returns to idle so I took her for a spin. No sputtering, shifts smooth and will maintain speed fine at lower speeds.

Now i have to go back and increase the main jet, she won't pull at full throttle.

This is definitely a learning experience. I'll keep you updated on my progress.

Thanks for all the input and help.

Tommy

[Big T]

Try

https://www.jetsrus.com

for your jetting needs

Fast service, good prices

[gixerbike1]

Finally, She's Alive

FINALLY, I got it running right...now i need clutch springs

I ended up with 160 mains, 1.5 turns out from lightly seated on the air screws, 22MM float height and the CR7EA plugs.

The needle is set with the clip 2nd down from the top. I took her out for a spin and she's a whole different beast, Runs smooth through the gears and pulls really strong, and fast, until the clutch starts to slip around 7k.

Other than that and new fork springs I need to get from Dennis Kirk, I think i'm good to go.

Thanks for all the help guys

[Steve]

You are changing too many things at once. Changing to a hotter plug is only a Band-Aid to cover up other problems. You might get good-looking plugs, but it might still be running too rich. You just won't know it because of the hotter plugs. Put the correct plugs in first, then adjust untl they look right.

Do plug chops to see what circuit is causing your rich conditions. Having the mixture screws out 4 turns might have been too much. With them now at only 2 turns, it might not be enough. Changing two full turns in one adjustment can't tell you much. You really need to make smaller adjustments, listen to what the engine is telling you, then continue.

.

[gixerbike1]

condensed

Hey Steve,

Thanks for the Info, However that was a condensed version of what i actually went through in an 8 hour troubleshooting session yesterday.

The bike still had a little bit of a stumble down low. I ended up putting the stock needles back in the carbs last night, Along with going to 2 complete turns out on the air fuel screws.

I haven't been doing all of this at one time, I been working one circuit at a time.

Once i was able to get it to idle, I took her out for a spin, if it didn't act right in a certain spot i worked that spot.

After several test rides and multiple small changes here and there the bike got better each time, so I knew i was heading in the right direction.

As far as the plugs go, I plan to go back to the D8EA's as soon as i get paid. The CR7EA's were more for getting me through the process as they didn't foul as easily as the stockers and gave me more troubleshooting sessions before going south.

The Low and Mid range's are now perfect and the high rpm pull is great, until the clutch starts slipping so a full redline pull is outta the question for now.

If it's still rich when i go back to the D8EA's then I'll deal with that issue then, might be float height related or i might need new air/fuel screws.

As with the clutch springs and the fork springs, I'm sure more 30 year old items that need to be replaced with pop up

For now, I'm just glad it's running good and i can actually ride it around with worry that it'll leave me stranded. The rest will come with time, and as money allows.

I'll keep you guys updated as i get more done, again thank everyone for your help and advise.

Tommy