And so it begins...GR650 carb teardown

[oldrookie]

First, let me express some amazement at the prompt service from Robert Barr at cycleorings.com. Ordered on Friday, parts in my hands at 11:00 Monday.

Second, I had already decided to take the carbs off and begin the teardown while waiting for my o-rings. Okay, that plan was foiled by very prompt service, but I went ahead with the "take the carbs off the bike" portion of the morning's entertainment anyway.

Third, here's hoping that PB Blaster is doing it's thing even as I write. Got the carbs off (wish me luck with the choke assembly when I put it back together) and can't get the screws to come loose so I can ungang them.

Question: Any real reason to ungang them if I can disassemble each carb and dip them while assembled? This bike is a twin cylinder, so a bit less complicated than the GS bikes. I left the bodies ganged together when I cleaned my Radian carbs (in-line four) several years ago with good success.

Fourth, a couple of the screw were slightly boogered by somebody in the past. Doesn't seem to me that these carbs were unganged in September unless they used Loctite on reassembly. I have the receipt for the work done, but this screws don't act like they've been apart.

 

[Nessism]

Use an impact driver and get them separated.

 

[oldrookie]

Use an impact driver and get them separated.

Okay. Just spoke with Griffin and he is planning to swing by tonight to take a look. He told me the same thing.

Used some advice he gave me and got the float pins out without damaging anything.

Still have the choke pins (or whatever they are called) and one other jet to pull. Pretty much torn down otherwise. Not as bad as I feared, at least so far.

Even took a heatstroke break (pretty hot in Indy today) and figured out a bass line to an older Weezer tune.

Pretty good day so far.

 

[Guest]

I feel something incredibly important is missing from this thread... pic's!!

A lot of us won't have seen the GR carbs before so we must see them now while you're doing this... and perhaps they can go to a tutorial along the lines of Nessism's and Flaming Chainsaws carb cleaning guides?

And thanks for putting this up too, the GR's have me interested although they're pretty rare over here...

 

[oldrookie]

Well, I took a few pictures to help me remember how it all is supposed to go back together, but the GR uses the very familiar Mikuni BS36SS carbs...but just the two.

I'm using the tutorials you cited to tear into mine, so not sure there'd be much new that I could add. You also have to remember that without the tutorials I'd be lost. Not sure we need the blind leading the blind here. That's what the rest of the Internet is for, right?

Well waiting for the PB Blaster to work I drained the oil and took the filter out. Picked one up with the o-ring at the local NAPA store and have reinstalled it.

Is this a good time to ask what the best oil to use is? (I kid! I kid!) Saw all the other threads on the subject and figured I launch that one in for fun.

On inspection, the float bowls are really clean, but I did see some crud in one jet and can't see through one other, so I think this should help.

Waiting on the intake boots to arrive at the local dealer's location so I can go pick those up.

Making progress.

 

[oldrookie]

More likely to see one there than here actually. Austrialian Military Police used them for a while. A quick image search for GR650 Military Police will get you some pictures of them in full dress.

 

[oldrookie]

Just spent an enjoyable evening talking bikes with GSR member Griffin. He came by and helped me get the last bits of the carbs apart. Also so brought his cans of carb cleaner to dip them when we got them apart. Impact drivers work well when somebody knows how to use them. (Griffin, not me.)

He also gave the bike a good look-over and suggested a plan of action for the next steps after the bike is running correctly. I appreciate his willingness to share his experience and expertise with a relative noob wrench. I've worked on cars some, but not much on bikes.

Extra points to him coming over on the hottest day of the year. It was still 94 degrees in the garage when he left at about 10 this evening.

 

[Guest]

Cool, I'll havta have a look around the shop and see what I can see...

And always good to see other members giving other members a hand, gotta love it

 

[Big Rich]

Atta boy Rook. Carbs aren't nearly as intimidating once you have them apart and in front of you.

I actually have a junk pair of BS36's around if you need an oddball part or two.

 

[oldrookie]

Thanks, Big Rich. It's all a learning experience and that's part of nearly 30 year old bike. Griffin really helped by prioritizing the things I need to consider as I get past the carb issue.

Pete, Griffin says these carbs are a bit different, so I will take few pictures of them as I put them back together. The phrase was "the same, but different."

 

[oldrookie]

Quick update. I spent most of the day putting my carbs back together. A couple of jets were in pretty bad shape, but I think they are sorted now. Pretty much done if I could remember how the throttle and choke assemblies reattach.

Didn't take enough pictures while taking them apart and Clymer's photographers have the remarkable ability to take photographs with almost no contrast or detail of the things I need to see.

Hoping my new intake boots are in tomorrow so I can find out whether I've solved the issues the bike was exhibiting.

May drain my tank while running the gas through a filter since I have it off the bike to see if there is any rust coming through the petcock. I don't see much rust, but this seems like a good time to confirm what I think I'm not seeing.

 

[Guest]

Sounds like a good plan to me! I left the fuel in my tank in the vain hope it would prevent it rusting... it's now lined with POR 15 after dealing with the rust...

 

[oldrookie]

Annnddd!!! She lives!

I got everything buttoned up and back together. No leaks, no runs, no errors.

Started very quickly and I took it for a short run through the neighborhood. Needed at least some choke for about 5 minutes. Noticed it wanted to stall with no choke at all.

Came back home and set the idle control screw to idle correctly with no choke and it just sits there purring like a kitten.

It does want to pop a little on deceleration if I rev it up, so I'll track that down. There is no change in idle when I spray the intake boots with electrical contact cleaner, so I'm not sure I needed new boots. Definitely needed the o-rings replaced in any case, so new boots might not be a bad idea in any case.

Oh yea, I drained some gas from my tank through a coffee filter to see if I could see any sediment from the tank. Strained quite a bit and the coffee filter remained clean and clear, so may not have to deal with any rust in the tank.

 

[oldrookie]

Swapped out the heavily carboned plugs for something called an E3. Some sort of a Splitfire type of plug. PO had left some new ones in the tool kit.

Bike seems much happier with new plugs, but I'm betting a sync job is in order. Runs okay and idles fine, but feels unhappy if you try to get on the gas a little hard. Gets vibey and doesn't go like I suspect it will when setup properly.

Mostly just chugging around the neighborhood right now. Too many other unknowns with the bike to get out on the main roads at the moment. Want to take care of the logical maintenance items and make sure it's running correctly before dodging cagers.

 

[Guest]

Well done! :clap:

Good news all round, I'm sure there's nothing a little tuning can't fix

Can't remember off the top of my head but you've done valve adjustments right? If not, do that before the carb tuning, otherwise you'll have to tune again most likely...

 

[oldrookie]

No, haven't jumped into the valve adjustment learning curve just yet. So many things to do, riding season goes so quickly.

And thanks for the encouragement, Pete!

I tried to take a few pictures, but I was really just too excited to get this rebuilt and see if it would run correctly. Not sure they are worth posting, but may give it a go later tonight.

Might see if I can get a video up so any interested inmates can hear the parallel twin doing its thing.

 

[Guest]

I'll happily watch the video

You'll wanna do the valves for sure, there have been many reports of very large improvements after proper valve adjustments...

I do understand the riding season comment, although here it's 365 days a year... unless of course your bike is not on the road yet

 

[oldrookie]

Thought I'd throw this up real quick. This is after a short ride. No choke. The popping seems to be from the left cylinder.

NOTE: I did not change the float levels or check the gas levels. Ran out of time before being compelled to deal with other life matters.
The Air mix screw is out two turns on both sides as a starting point.

Valves have NOT been adjusted-plan to get to it, but hasn't happened yet.

The video compression did something strange to the aspect ratio of the video.

(Removed the original video and put a different video link in. This one is later in the process after I adjusted the valve, bench sync'd and mixture screw set better.)

http://www.youtube.com/watch?v=L2myqX--jf0

 

[Guest]

While I can't really comment on the popping (not a carb guru here, just know how to clean 'em ), that sounded pretty good to me!

It certainly sounds like it's running well, just needs a slight bit of tuning...

 

[oldrookie]

Well, more reading in the Welcome pages led me to try something. I had read, somewhere, that two turns out on the air mixture screw was a good starting point. That's how it was setup in the video.

Saw that the GS gurus recommend 3 turns out as a good starting point. Went out to the garage, turned each screw one more revolution and lit a fire in the old girl.

Revs up to redline easily now, wouldn't do it before and all the popping has virtually disappeared.

Trying not to interject a premature whoo-hoo, which I usually do when dealing with things of this sort, but it seems significantly better. One little pop on a quick chop of the throttle from the redline.

Going for a short ride to see if it has smoothed out under way.