Wanted: Service in San Diego

[Guest]

Hey All,

Sorry if this is the wrong location for this post, but I couldnt find a better place to put it.

I have spent about 40 hours trying to get my 1980 GS550E to run well and just cant do it. I rode it over to a modern motorcycle repair shop, they spent 8 hours, and it still ran poorly. Then I gave it to my brother who is a porsche mechanic, he spent 10 hours, and it still runs poorly. Keep in mind that the engine/exhaust/airbox/jets are all completely stock.

Is there anyone in San Diego that is an expert on these old bikes that would be willing to fix/tune it for a reasonable wage? Or if you can recommend a shop that knows their stuff, I would appreciate it! I realize there are good carb cleaning services on this board, but thought I would first try to find someone who could get the bike running well, as I would hate to pay to rebuild the carb just for it to still have issues.

Background: I bought this bike back in 2014 and it ran close to perfect. Idled right at 900 rpms and ran very well except for a dip in power around 3K rpms. Then by late 2016, the carbs were getting a bit dirty and it wouldnt hold idle. At this time I took the carbs apart and really gave them a good cleaning. I also put in a carb rebuild kit (I still have the stock parts, but confirmed all new parts matched perfectly). Once this was done, no one could get it to work well. Currently it starts without choke and will idle around 2K rpms (if you drop the RPMs lower it wont hold idle). Then, it has absolutely no power under 4K RPMS. Like hard to get moving power. Once you get above these RPMs, it runs beautifully and will rev all the way up to redline with good power.

[1978GS750E]

Carb rebuild kit???? All you really need are the O-rings from cycleorings.com and bowl gaskets possibly. I would suspect the carb rebuild kit parts, especially if they came from China or the like!

Just my $.02.

[Tenshots1]

Carb rebuild kit???? All you really need are the O-rings from cycleorings.com and bowl gaskets possibly. I would suspect the carb rebuild kit parts, especially if they came from China or the like!

Just my $.02.

I realize this and am thinking the next task will be putting all of the stock parts back in and getting the o-rings. Problem is I have a 1 month old son, a 17 month old daughter, and a job where I work consistent 55 hour weeks. So at this point I just need a pro to work some magic. Even though I love doing stuff myself, I'm going to have to settle for paying right now.

[Redman]

My observation relative to working on these GSes is that there is no subsitute for expereince with these GSes. SOmeone may have lots of expereince with other bikes in general. But they really need specific expereince withg GSes to know the common problems.

.................
this time I took the carbs apart and really gave them a good cleaning.............

Describe "good cleaning".

................. Currently it starts without choke and will idle around 2K rpms (if you drop the RPMs lower it wont hold idle). .........

That seems like a symptom that someone (not me) can identify.

................. Then, it has absolutely no power under 4K RPMS. Like hard to get moving power. Once you get above these RPMs, it runs beautifully and will rev all the way up to redline with good power.

THat sounds like a dirty carb problem.

[cowboyup3371]

Get the carbs cleaned properly, do the valve adjustment, and a lot of your issues will settle down.

[Tenshots1]

My observation relative to working on these GSes is that there is no subsitute for expereince with these GSes. SOmeone may have lots of expereince with other bikes in general. But they really need specific expereince withg GSes to know the common problems.

Describe "good cleaning".

That seems like a symptom that someone (not me) can identify.

THat sounds like a dirty carb problem.

By “good cleaning”, I mean the carbs and individual pieces were dunked in a carb cleaner solution overnight, brushed with a toothbrush, and then sprayed with carb cleaner as I went. They were pretty spotless by the time I was done.

regarding the other poster, I check valve clearance during this rebuild and confirmed I was within spec for all valves.

Anyway, I don’t want this to become a “problem solving” thread as much as I appreciate the tips. At this point I’m looking for someone good in SD that I could pay to make the bike tip top. As mentioned, there is no substitute for experience on these.

[cowboyup3371]

I know you are very busy with home life and most of us have been there as well. However, honestly, you're going to find the best way to do this is for you to do the work and let us help from afar with advice like this. Too many shops don't know how to work on our old bikes and really won't take them because of the risk associated with them. And many of the shops that will charge exorbitant fees and won't always do what's right for the bike.

Nessism is in that general area (think he's over in LA more than San Diego but I could be wrong) so reach out to him directly and see what he may suggest.

[fastbysuzuki]

Bit to much of a coincidence that when you put in a carb rebuild kit it would not run well being you have the original parts I would do a full carb strip and clean/ dip new orings via http://www.cycleorings.com/ and replace the jets with the original parts set them as the manual says, fresh petrol then when that's done then report back
workshop manual here http://zeus.mtsac.edu/~cliff/storage...-ES-L_1983.PDF
There are members on here that offer their services to strip/clean and initial carb setup for a reasonable cost.

[Tenshots1]

So i changed the jets back last night, adjusted one float a bit, and put it back together last night. Now its running Waaaaaay better. Idles right around 1K, accelerates pretty well. Looks like the aftermarket rebuild kit was causing all of the issues. By the way i checked the kit against the original parts when swapping them out and they look identical with identical markings on the sides.

Thanks all for your advice. I still need to sync the carbs, install new o-rings (small gas leak in carb 3), and slim down the plastic retainer on the needle to richen the mixture around 3K RPMS. Other than that, it is running pretty well and i will be able to take it to the distinguished gentlemens ride on Sunday.

[Steve]

Thanks for the follow-up report.

Yes, it's rather amazing how little a difference in jet sizes it takes to make a big difference in how the bike runs. The kids in the Chinese factories can stamp just about any number on a jet and you will <think> it's the right size, but you won't really know. That is why we highly recommend using the original jets when possible, or at least getting genuine Mikuni jets, which are easily obtained at a reasonable cost. As you have found, the parts in the "rebuild kit" are often of questionable quality.

By the way, rather than "slim down the plastic retainer", use a stack of 3mm washers, instead. A stack of 5 washers is the same thickness as the plastic spacer, so remove the spacer, install two or three washers in its place. This makes the process reversible and adjustable.

.

[Tenshots1]

Thanks for the follow-up report.

Yes, it's rather amazing how little a difference in jet sizes it takes to make a big difference in how the bike runs. The kids in the Chinese factories can stamp just about any number on a jet and you will <think> it's the right size, but you won't really know. That is why we highly recommend using the original jets when possible, or at least getting genuine Mikuni jets, which are easily obtained at a reasonable cost. As you have found, the parts in the "rebuild kit" are often of questionable quality.

By the way, rather than "slim down the plastic retainer", use a stack of 3mm washers, instead. A stack of 5 washers is the same thickness as the plastic spacer, so remove the spacer, install two or three washers in its place. This makes the process reversible and adjustable.

.

Good tip. Thanks Steve.

By the way, I did the DGR ride on Sunday. Put about 100 miles under the bike. It ran and idled like a champ. Was a great day! Except for one of my sidecovers popping off and getting ran over by a car.

[salty_monk]

radioshack used to sell a pack of those washers for peanuts.. more than you'd ever need. I think you could probably get them at a Tru Valu or Ace though or Ebay...

[Steve]

Jets R Us has a 10-pack for $5.39. Flat-rate shipping of $7.99

Bolt Depot has zinc-plated steel 3mm washers for a nickel a piece, or a bag of 100 for $1.16. Shipping is $4.95

Bolt Depot also has stainless 3mm washers for a nickel a piece or a bag of 100 for $1.10. Shipping is the same at $4.95.

I haven't ordered anything from Jets R Us lately, but I ordered something from Bolt Depot just last week. Ordered Monday evening, got an e-mail Tuesday afternoon saying it had shipped, I had it Thursday.

.

[Tenshots1]

Thanks for the follow-up report.

Yes, it's rather amazing how little a difference in jet sizes it takes to make a big difference in how the bike runs. The kids in the Chinese factories can stamp just about any number on a jet and you will <think> it's the right size, but you won't really know. That is why we highly recommend using the original jets when possible, or at least getting genuine Mikuni jets, which are easily obtained at a reasonable cost. As you have found, the parts in the "rebuild kit" are often of questionable quality.

By the way, rather than "slim down the plastic retainer", use a stack of 3mm washers, instead. A stack of 5 washers is the same thickness as the plastic spacer, so remove the spacer, install two or three washers in its place. This makes the process reversible and adjustable.

.

And it is common that these bikes run lean around 3K RPMs, not rich right? I think I read this. My acceleration bogs from 2,500-3,500, and has since i have owned the bike, but I am not sure whether this is a rich or lean condition. Usually it just accelerates about half as fast through the RPMs.