Honda CX 500 Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
95 Posts
Discussion Starter · #1 ·
Short story: cleaned a set of carbs using the Larry method. Worked great.



Longer story: I just completed a full dismantling, cleaning, and reassembly of a set of carbs for my 82 GL500I, and I was surprised how easy it was to do - with the help of experts. Going in I thought it might be a recipe for learning a lot and junking a set of carbs, but I put about 50 miles on them yesterday and today with nary a stumble at any RPM.



I got a set of carbs off the Internet a couple weeks ago labeled as complete but unknown condition. I'd already purchased a Harbor Freight ultrasonic cleaner, and got a copy of the Carb Rebuilding book from Larry (LRCXed on the forum). I took the carbs apart per the instructions in the book, keeping the left side parts separate from the right side parts. In retrospect that wasn't necessary, but my engineering background pushed me towards the organized approach. There really aren't that many parts to these carbs, but the ones that are there are important ones! Everything went into the ultrasonic with Simple Green and H20 in 3 batches - left body and parts, right body and parts, and jets by themselves. Again, probably not necessary to keep everything apart, but...



The ultrasonic is pretty amazing. Grease/dirt "boils" off the parts and dirties the cleaning solution quickly. Depending on how dirty things are to start, I think you have to change the water more often than the twice per batch that I did. The dirty water combined with ultrasound will actually stain the carb metal if left too long. I cleaned mine for about 2.5 hours each batch, turning the parts often to let things fall out. Carb cleaner flushing, hot water, and compressed air then gets most of the left-over gunk out except for the small holes in the jets. I used twist drill bits for those, since I guess someone smarter than me decided they should be .018" diameter and not .019" or telephone wire size. There are multiple relief valves that could also be taken apart, but since mine were working with compressed air I didn't get into them.



Putting things together is always a little more interesting than taking them apart, but again the instructions in the book kept me straight. Since I separated my bodies, I had to re-install the choke spring and get everything aligned pretty close so tubes, shafts and linkages between the two didn't bind. Also the better you get the two working together on the bench the easier syncing will be later on when they are installed. The o-rings seemed to be in good shape so I re-used everything, but it's probably prudent to at least replace the ones on the idle mixture screws and on the fuel crossover tubes. Gasket/o-ring set is $50/carb at Honda, $40-ish at discount. Total bench time the first time ever taking a carb apart was probably 8+ hours, but I wasn't in a hurry and that includes all the flushing and blowing. Next time less, for sure if the bodies aren't separated.



Got everything back together, installed and balanced using a Morgan CarbTune II. No leaks, idle is smooth at 1000 rpm, and acceleration is remarkably improved. I had been complaining that my bike didn't jump off the line like others I'd had in the class, but now I think it's right there. I hadn't really had any discernible problems with the old carb set other than weak acceleration performance, and it looks like the cleaning has corrected that. Can't speak to hesitations at certain rpms or after warm-up or some of the other issues seen around this site, but I'm now a firm believer in cleaning your pipes and orifices - at least the ones on your carbs.



Thanks to Larry and Blue Fox for the technical and moral support.
 

·
Registered
Joined
·
2,282 Posts
Good job, Dude. These carbs are not as intimidating as most people feel. By taking your time and not rushing, you ended up with a fully serviceable set of carbs. So many guys just spray the outside with carb cleaner, shake out the rust from the float bowl and report that they have perfectly cleaned carbs, but still have problems.



How far off was the bench syncing when you checked with the Carbtune? Just curious on how accurate bench syncing can be.



Now we know that you don't have to be a "rocket scientist" to work on these carbs. Wait, you are kinda a rocket scientist, so that may not apply.
 

·
Registered
Joined
·
95 Posts
Discussion Starter · #3 ·
How far off was the bench syncing when you checked with the Carbtune? Just curious on how accurate bench syncing can be.


The CarbTune showed 4 cm Hg, which is probably about the time you'd start noticing a performance difference. If I remember right, I was well within a half-turn of the adjusting screw. Now that I know what an "off-idle" hole is, I think I could get them tighter than that on the bench, assuming there aren't any internal things making a difference.



 

·
Registered
Joined
·
198 Posts
Glad to read your report, I have this coming up. I did a spray & pray job shortly after I got the bike. It got the bike running, but not right. Larry's book has arrived, and I'm going to do it right this time. Just need a day off work and a clear mind. Both are in short supply.
 

·
Registered
Joined
·
95 Posts
Discussion Starter · #5 ·
Hope it goes smoothly. I did another set this afternoon and got them back together a couple hours ago. Took everything apart again, separating the bodies. Just my luck, one of the ACVs (air cutoff valves) was missing an o-ring. The boys on here say you can close off the valve and adjust the mixture to compensate, but I may look around the aerospace giant I work for tomorrow to see if I can borrow one for several years.



If you use the ultrasonic cleaner method, think about not putting the accelerator pump cover into the cleaner. It is made of a porous pot-metal type material that seems to not like the ultrasound.



Good luck!
 

·
Registered
Joined
·
58 Posts
I keep reading about "Larry's Book". Is this the same as the instructions posted online or is this different?
 

·
Registered
Joined
·
1,219 Posts
For anyone that does not have an ultrasonic cleaner, it is not needed IMO. Just strip the bodies and soak them in 1/3 pinesol and 2/3 H20 solution. They will be good to go after 1-2 days. You can do this and leave the accel. pump on.
 

·
Registered
Joined
·
95 Posts
Discussion Starter · #8 ·
I keep reading about "Larry's Book". Is this the same as the instructions posted online or is this different?
There have been some general "how to" posts about carb cleaning on this forum, but I haven't seen the type of step-by-step detail and pictures you can get from a book that was put together by one of the forum members named Larry (LRCXed). The Grand Nagus (Blindstitch) just put up a link to his info, but I can't put my finger on it right now.



There are many ways to skin a carb, and if you are a mechanic you may get good results by just jumping in, but it was reassuring to me to have a book as a guide, just like having a service manual when wrenching on other parts.
 

·
Super Moderator
Joined
·
15,413 Posts

·
Registered
Joined
·
58 Posts
Thanks, may have to get one of those books as I'm sure I'll be keeping the bike and will need to rebuild the carbs at some point.
 

·
Super Moderator
Joined
·
15,413 Posts
Whenever someone asks a question like "What's this carb part" or "Where does this go" I consult the book and find the answer pretty quick and a picture showing what I need to know.
 

·
Registered
Joined
·
269 Posts
I am a professional mechanic.

and have a lot of success rebuilding carbs for cars and motorcycles for years.

I still bought a copy of larry's book.



it is just that good.
 

·
Super Moderator
Joined
·
2,853 Posts
Showmedude and all the rest of you that posted to this, Thank you for this thread. It's nice to see the stories of success and support for the methods used in my book. Since this is the new sight for CC it doesn't have many of the results posted from past members experiences.



Stitch is right though. The more I got into these the better the techniques got. I'm glad it took me so long to finish the book because the more I hesitated the more I learned from the members on what they needed to know. So thanks go out to all those that ever asked questions or had problems in the past. We all benefited from them.



Phil, I'm going to soak a set in the pinsol solution some day just to see how good it does. I'm curious to see if it will remove the built up crustacean inside the low jet in particular. In fact I think I'll put some jets in some of it today and see what it does.



Thanks again guys! Ride safe out there.



Larry
 

·
Registered
Joined
·
1,219 Posts
Showmedude and all the rest of you that posted to this, Thank you for this thread. It's nice to see the stories of success and support for the methods used in my book. Since this is the new sight for CC it doesn't have many of the results posted from past members experiences.



Stitch is right though. The more I got into these the better the techniques got. I'm glad it took me so long to finish the book because the more I hesitated the more I learned from the members on what they needed to know. So thanks go out to all those that ever asked questions or had problems in the past. We all benefited from them.



Phil, I'm going to soak a set in the pinsol solution some day just to see how good it does. I'm curious to see if it will remove the built up crustacean inside the low jet in particular. In fact I think I'll put some jets in some of it today and see what it does.



Thanks again guys! Ride safe out there.



Larry


Let me know what you find. I remove all jets before I soak mine.
 
1 - 15 of 15 Posts
Top