Poor performance puzzling me..

[Guest]

With all the tweaks you've done it's time to try another ignitor.

 

[TheBigRed]

With all the tweaks you've done it's time to try another ignitor.

Oh, yeah, forgot about that. When it lost spark last spring after bringing it home this was another suspect item that I swapped from the 650 to the 550 (after double/tripple checking that the part numbers were the same) to make sure it wasn't blown when the R/R shorted out at Duanes. I'm getting spark on all four, and as you can see from the plugs it looks like I am a tad on the lean side.

Amos

 

[TheBigRed]

Just took 30 min to check the diaphrams and indexing. They were all good and indexed correctly.

Now the bad news.. I was doing it on the bike and ended up cross threading one of the screws when trying to get it back in. Good news is they are through holes and I have a tap and die set so I should be able to repair the threads, but that means taking the carbs off of the bike and dis-assembling the rack.

Oh well. In thinking about it last night I figured I'd order the rubber boots from the plenum to the carbs anyway so that we can eliminate them as the cause as well.

I'd like to order jets as well if I have to do that down the road anyway (really don't like taking off and putting the carbs back on all the time) but don't know what size to go with (especially at $7 a piece)?

Amos

 

[rustybronco]

Actually the jetting looks to be slightly rich, especially the second from the left and the one on the right. BUT! what color is showing way down deep where the insulator meets the outer shell? that is where you check the main jetting.

when your bike hits that wall, does it sound like the ignition (spark) is breaking up?

beg borrow or ? a timing light and check the advance.

you can also check for erratic spark with the timing light, it will show up as erratic flashing.

 

[Nessism]

If you have another ignitor I'd try it as Chef suggests. The engine hitting a wall is a common symptom of ignitor failure. Those holes in the mufflers will change the mixture some but not enough to cause the bike to fall on it's face. You could always go up a couple sizes on the mains and try but you shouldn't need an entire jet kit as long as the stock airbox is still in place. Only other thing I can think of is to make sure your ignition advance is working - grab hold of the rotor and turn it with your fingers, it should rotate a few degrees and snap back under spring load when you release it.

Good luck and hope you figure it out.

 

[drejal]

this thread caught my eye, because it's slightly similar to a problem I was having with my 550L. I just skimmed through the thread so, if this idea has been covered/solved, forgive me!

Have you checked the voltage to the coils? My 550 was "hitting a wall" when I started getting around 5~6k, and it would stumble up to about 8k, and just couldn't make it to redline. Found I only had 9.5v @ the coils, did coil relay mod, now getting full 12V at coils, and it easily hits redline now.

just my $.02 worth.

AA

 

[Turtleface]

this thread caught my eye, because it's slightly similar to a problem I was having with my 550L. I just skimmed through the thread so, if this idea has been covered/solved, forgive me!

Have you checked the voltage to the coils? My 550 was "hitting a wall" when I started getting around 5~6k, and it would stumble up to about 8k, and just couldn't make it to redline. Found I only had 9.5v @ the coils, did coil relay mod, now getting full 12V at coils, and it easily hits redline now.

just my $.02 worth.

AA

I had the same thing on my 1100E. Engine ran perfect up until about 5-6k, then lost all ability to accelerate. Bike would usually maintain speed @ about 45-50. Tone of the engine would also change as well. My coils needed replacing, coil mod alone wasn't enough. Might be worth it to break out the multi-meter.

 

[Rick65Cat]

• Changed air filter back to K&N drop in replacement. No improvement

1. Loosen air filter element to allow freer air flow to see if maybe filters are over-oiled and not allowing enough air flow for engine

Amos

(I read through all the posts, and didn't see anyone responding about this.)

Yup been there, done that. Wouldn't rev in the upper ranges. I had to re-wash out my filter then oil it again. Only sparingly the second time.
Ran much better.

Rinse yours out, dry it as best you can and give it a short test run without oil. A short run won't hurt it without oil.

 

[TheBigRed]

Now the bad news.. I was doing it on the bike and ended up cross threading one of the screws when trying to get it back in.

I used the tap and die set to re-run the threads on the screw itself, then was able to get it threaded back into the hole, carefully, so while I may want to address this down the road things are back together for now.

Actually the jetting looks to be slightly rich, especially the second from the left and the one on the right. BUT! what color is showing way down deep where the insulator meets the outer shell? that is where you check the main jetting.

when your bike hits that wall, does it sound like the ignition (spark) is breaking up?

beg borrow or ? a timing light and check the advance.

you can also check for erratic spark with the timing light, it will show up as erratic flashing.

The color down appears (as best I can see it) to be a light tan, but it is hard to see all the way down in there..

I may have to see if the local auto store has a timing light, I'm just not sure I would know how to use it properly..

Only other thing I can think of is to make sure your ignition advance is working - grab hold of the rotor and turn it with your fingers, it should rotate a few degrees and snap back under spring load when you release it.

Good luck and hope you figure it out.

Ness, I've actually already checked that, even watched it with the engine running to see it expand out then come back in, it appears to be working properly.

Have you checked the voltage to the coils? My 550 was "hitting a wall" when I started getting around 5~6k, and it would stumble up to about 8k, and just couldn't make it to redline. Found I only had 9.5v @ the coils, did coil relay mod, now getting full 12V at coils, and it easily hits redline now.

just my $.02 worth.

AA

Drejal, That got me thinking and I went out and took a few measurements. With the headlight on and ignition turned on I was getting about 9V from the coils to ground, when I turned the headlight off it jumped up to about 10.5V. That's when I realized I soldered the spade connectors that I had to add to the harness since the 550's coils were hard wired, and thought (since I'm really not that good at soldering) could be eating some of the voltage. I cut off my connectors and just crimped some on instead, that got me up to about 11.4V (since I had been doing testing etc I thought that would be close enough as the battery was probably discharging during my measurements, however I didn't think about it till later I should have measured the battery voltage to verify.

Took it out for a ride after that, and I've still got the problem. I may still look into the relay mod down the road a bit though.

(I read through all the posts, and didn't see anyone responding about this.)

Yup been there, done that. Wouldn't rev in the upper ranges. I had to re-wash out my filter then oil it again. Only sparingly the second time.
Ran much better.

Rinse yours out, dry it as best you can and give it a short test run without oil. A short run won't hurt it without oil.

This is simple enough for me to try out, and is on my list above. The oil used is what came with it in the little tube, and who knows how old it is. I have a K&N recharge kit so I'll give it a try sometime this week.



As another note, on my ride I did pay closer attention to things and it will run above 5k and not "hit a wall" as long as I"m patient in getting there and use no more than 1/2 throttle, anything above that and it changes everything, but below that throttle opening it will pull, all be it slowly above 5k without the change (it's just very hard to not keep opening the throttle however slowly as you are accelerating. )

Amos

 

[gina1984]

I think instead of trying again and again its better to go and meet the auto mechanic and get the solution of your problem.

 

[TheBigRed]

The Drop in K&N is out of the equation now. Not coming back in either, at least not anytime soon.

When I went to clean it I noticed the seal between the metal used to secure it and the rubber that actually holds the filter is broken/ripped, thus allowing for air to freely enter without filtration.

I'm not going to say this was the cause of the issue, as stated in the first post the symptoms were the same with it and the stock with uni foam installed.

BTW, how oiled should the foam be? I thought it was oil it then squeeze it with a paper towel to get excess oil out (not wring, but press). But maybe this caused there to be not enough oil on the foam??

Amos

 

[TheBigRed]

I'd suggest, for these trials, sticking with the UNI filter, as you are correct, its CLOSEST to factory flow. Starting at the airbox, what can we look at?
1) are you running the lid on the box?
2) if so, is the airbox SEALED properly?
3) are the airbox boots seated and sealing well? (ive had them LOOK as if they are, but move the box and Ta Da! they slip right off the carbs.. which is the same as running NO filter restriction, and will do exactly what you are talking about. If they are hard, they've usually shrunken back toward the box, and really arent doing their job)

Going to go off of your message for a bit here CafeKid to rule things out.

.5 (before your list of questions on the uni foam) After thinking about this more (see other post) I'm thinking I did not Oil the foam correctly. A) I used K&N spray oil to oil it. B) I used paper towel when "sqeezing" excess oil out. C) The manual says to use motor oil and pictures the squeezing without anything to draw excess out.

1) Yes, the airbox lid is in place.
2) Already answered, but airbox lid has fresh weather stripping around it.
3) I'm not sure on the seal here, they look sealed, and don't come loose when wiggling/moving the box, but I have ordered replacements. Specifically when re-assembling the carbs onto the bike I backed them into the airbox boots first, tightened down the straps to hold them in place then moved the carbs forward into the intake boots and there was no loss of connection or visual movement on the airbox side.


So, tonight I'm going to re-oil the Uni foam with motor oil, and squeeze it out by hand and try to get out for a ride and see if properly oiling that makes a difference by restricting air intake any.

I'll report back when I can.

Amos

[Edit] By the way, for others. Last time I took the bike out (Saturday afternoon) I was able to get the RPM's to around 6k but to get there the throttle could not be open past the 1/2. (just noticed I noted that above oops) But anyway, I think that rules out anything electrical/timing related as it was able to get there all be it SLOWLY[/Edit]

 

[TheBigRed]

Well, that didn't work, in fact it seems to have made it worse.


I'm done for a few days till the parts show up that I ordered..

Amos

 

[TheBigRed]

Motors only need three thing to run, air, fuel, and fire. Its not getting enough of one of those up top...

Rinse yours out, dry it as best you can and give it a short test run without oil. A short run won't hurt it without oil.

I'm done for a few days till the parts show up that I ordered..

Amos

I LIED, I'm sorry. I just couldn't let it alone tonight. Soo...

I cut another piece of the UNI foam and placed it in the filter holder WITHOUT any oil.

The results, somewhat the same, but the change in the engine feel wasn't near as dramatic as it had been before, let alone with the super oiled UNI foam.

So, I'm thinking I need more air flow in/through the carbs.

That being said.. here are the jet/carb specs for the 550T, and what is in mine (the only exception being possibly the Jet Needle, but I'm 85% sure it is the right one).

GS550 (80-82) the specs are for the CV's

idle r/min 1100-+/-100r/min
carb mik bs32ss (4 seprate carbs)
id no 47070
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-1.0 (0.20 +/-0.04)
main jet #92.5
main air jet 1.6
jet needle 4bel2
needle jet x-6
pilot jet #40
throttle valve #140
by pass 0.9, 0.7, 0.7
pilot outlet 0.7
valve seat 2.0
starter jet #35
pilot screw 3.5 turns back (mixture screw)
pilot air jet #150

I may have been wrong earlier when I stated that I kept the OEM 650 jets, as the markings on the Main Jet is a different type of imprint. I haven't been able to find any charts that compare what K&L kit sizes correspond to Mikuni sizes, but here is the factor specs for the 650E's jets (I'll get to the point after).

GS650EZ (82 model) the specs are for the CV's

idle r/min 1100-+/-50r/min
carb mik bs32ss (4 seprate carbs)
id no 34260
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-1.0 (0.20 +/-0.04)
main jet #97.5
main air jet 2.0
jet needle 5c45
needle jet Y-7
pilot jet #42.5
throttle valve #125
by pass 0.8, 0.7, 0.8
pilot outlet 0.7
valve seat 2.0
starter jet #47.5
pilot screw 3.5 turns back (mixture screw)
pilot air jet #175

So, stock jetting isn't as HUGE of a jump as it would seem, assuming I have the K&L kit and their jet's are in fact the proper size for the 650 would it be worth trying them out at least to see what affect they have? If so, which jets would I change, the main and main air jet?

Amos

 

[TheBigRed]

That being said.. here are the jet/carb specs for the 550T, and what is in mine (the only exception being possibly the Jet Needle, but I'm 85% sure it is the right one).

Ok, for those that may still be following this thread here is the latest.

Duane (the builder) said that it sounded like I was lean on the needle jets etc. and has generously shipped a spare set of carb bodies to me (they haven't arrived yet).

So, today I did some research to work on fully understanding the carbs etc. Another forum member suggested checking where the spacer for the jet needle was in relation to the circlip. so, tonight I tore into that (doesn't require pulling the carbs.

I can say for 100% certainty that the jet needles are the correct ones for the 550T!!

Also, I found that the spacer was on top of the clip, which would cause a lean mixture when on the needle. So, I went through and swapped them all to below the clip to richen things up there. It's too late to take it for a ride tonight, but I think I'll take it to work tomorrow to see how it's acting.

Just more FYI, and talking to myself.

Amos

 

[TheBigRed]

Also, I found that the spacer was on top of the clip, which would cause a lean mixture when on the needle. So, I went through and swapped them all to below the clip to richen things up there. It's too late to take it for a ride tonight, but I think I'll take it to work tomorrow to see how it's acting.

Here are the results..

The issue is now sitting around 4k instead of 5k, so I don't know what to think. I did manage to get beyond that though by holding full throttle for like 30 seconds it would move beyond, at one point surging, then took off like crazy with a little bit of surging.

Amos

 

[rustybronco]

try lowering the needles.

dunno if it will help any but its nice reading.

http://scootrs.com/tech.cfm?tip=tunecarb

 

[TheBigRed]

try lowering the needles.

dunno if it will help any but its nice reading.

http://scootrs.com/tech.cfm?tip=tunecarb

I've heard of swapping the spacer out for the washers but with a stock needle can I add more washers to the spacer? Or do I need to start looking for a set of adjustable needles? (did some searching yesterday and didn't find any straight needles, just jet kits, but nothing available for the 550T, and the closest was a stage3 kit for the 550M, but I don't think I need a stage3.)

Amos

 

[Guest]

Surging is a lean condition. I'd raise the main jet first and then mess with the jet needle.

 

[TheBigRed]

Surging is a lean condition. I'd raise the main jet first and then mess with the jet needle.

Ok, I'm still waiting on my co-worker to get me the contact information for a guy he knows that is about an hour away with "cabinets full of jets." I'm hoping he'll work with me in that I can purchase a set of jets and just trade even up till I find what exactly I need.

It would be nice to get some hint as to where I should go from the 92.5's that are in there. Do you think I should go up to 97.5's or just go one step to the 95's?

I guess this will be more important if I'm having to buy complete sets each time, where if this guy will work with me then it may not be so critical to get it right the first time (except to save me some frustration).

Amos