Help! 78 GS550E .....60 mph.......Mooooaahhh

[Anonymous]

I've had this 550 for four weeks so far i have installed carb kits into spotless carb bodies, new battery, ngk plugs and condensors. I have gapped and timed the ignition and syncd the carbs. Engine compression is 90 lbs in each cylinder(has 14,000 miles on it)Vaccum lines are good, all carb boots seal and the vaccum petcock works perfect. and for all my effort when i go past 2/3 throttle i get rewarded with a sickening mmoooaahh sound and it bucks like a mule that got kicked in the jimmies. I have both sets of screws bottomed out and it still runs a bit lean! I would think it wuld smoke like a freight train. If anyone could give me two cents free i could afford it. Also what are the proper jet sizes for a 550 with stock exhaust.(maybe wrong size jets?)
Thanks a lot

Neal Yoest

yoest1@hotmail.com

[Anonymous]

What kind of air filter do you use? Is it stock? If yes, is the foam filter still there? You won't get the engine running properly without the foam filter in the airbox.

[earlfor]

Re: Help! 78 GS550E .....60 mph.......Mooooaahhh

I believe you bike has points ignition and VM (slide) carbs. What are your point gaps set to? What marks are you timed to at what rpm?
You said you have scynchronized the carbs. How many inches of vacuum are you drawing at what rpm? Did you hold the throttle open when doing the compression check? 90 pounds sounds a bit low.
You say you have both sets of screws bottomed out. There is an idle air adjustment screw and a pilot fuel screw, Bottomed out to me means turned all the way in. If this is true then you have your idle fuel and air controls shut down with the screws bottomed out. Turning the fuel pilot screw out increases fuel flow and richens mixture. Turning the idle air screw out increases air flow and LEANS mixture. Please explain your adjustments. I need more information to be able to try to help.

Earl

I've had this 550 for four weeks so far i have installed carb kits into spotless carb bodies, new battery, ngk plugs and condensors. I have gapped and timed the ignition and syncd the carbs. Engine compression is 90 lbs in each cylinder(has 14,000 miles on it)Vaccum lines are good, all carb boots seal and the vaccum petcock works perfect. and for all my effort when i go past 2/3 throttle i get rewarded with a sickening mmoooaahh sound and it bucks like a mule that got kicked in the jimmies. I have both sets of screws bottomed out and it still runs a bit lean! I would think it wuld smoke like a freight train. If anyone could give me two cents free i could afford it. Also what are the proper jet sizes for a 550 with stock exhaust.(maybe wrong size jets?)
Thanks a lot

Neal Yoest

yoest1@hotmail.com

[Anonymous]

what does VM stand for anyway?

[earlfor]

I really dont have an idea on that one Rick. :-)

Earl

what does VM stand for anyway?

[Anonymous]

mooaahh

I turned the screw on top of the carb base all the way in, down or closed. I did the same thing with the one located under the carb floats. It would make sense i was fighting myself. As for the timing, i hooked a test light to 1,4 points and rolled it over by hand until the light went out and it aligned with the F mark in the timing window. it's gapped at 14. Same thing for 2&3. I don't have a manual for this yet but thats how i did a honda cb and it worked well. as for compression i already had all the plugs out so i just used the starter, not the best way but i know the lowest compresion it has now. It drew 16-17 incehes of merc on the syncro. Long story short I purchased this bike from a lady who got it from a junkyard. No one in the last three owners before has had it runing, so i'm really excited that it just moves.

Thanks for the replies

Neal

p.s. no air filter, the basket i got the bike in didn't have one LOL

[earlfor]

Re: mooaahh

I dont have a 550, I have a 79 750 with slide carbs. I gather from reading posts from various 550 owners that the carb needle settings are more open on the 550's than the 750's for idle range. My carb air screws (screw on top of the carb) is set to 2 turns out. The fuel pilot screw (underneath at the edge of the floatbowl) is set to 1 3/4 turns out. This may not be optimum for your 550, but it should idle on those settings. If anything, you may need to turn the fuel pilot screw out another 1/4 to 1/2 turn
I think most of your problem is that there is no aircleaner box and filter.
The bike will not run without one. I dont feel there is any point in trying to tweak it to run decently until you have the airbox and filter on it as the induction system is badly mismatched in this configuration.


Earl

I turned the screw on top of the carb base all the way in, down or closed. I did the same thing with the one located under the carb floats. It would make sense i was fighting myself. As for the timing, i hooked a test light to 1,4 points and rolled it over by hand until the light went out and it aligned with the F mark in the timing window. it's gapped at 14. Same thing for 2&3. I don't have a manual for this yet but thats how i did a honda cb and it worked well. as for compression i already had all the plugs out so i just used the starter, not the best way but i know the lowest compresion it has now. It drew 16-17 incehes of merc on the syncro. Long story short I purchased this bike from a lady who got it from a junkyard. No one in the last three owners before has had it runing, so i'm really excited that it just moves.

Thanks for the replies

Neal

p.s. no air filter, the basket i got the bike in didn't have one LOL