Is there a trick to reinstalling Carbs?

MatC · Post by **MatC** » Sun Jun 29, 2003 10:52 am

I have a 79 CBX which I replaced the valves and head gasket. I also took the carbs out and reworked them. I am now trying to put the carbs back on the engine and I am having the darnest time. Is there something I don't get about putting these things on? What's the trick?

Whose idea was it to slant the carbs the way they did, anyway? It makes it nearly impossible!!

HondaCBX6 · Post by **HondaCBX6** » Sun Jun 29, 2003 12:00 pm

Relax!

Get a good beer and take a breath! There are a few ways to get them back on. First question is....Are the boots new? They are not too expensive and really make it easier. Inspect the ones on you bike. If there are any cracks replace them! I have tipped the motor and used a 2X4 and my legs. (worked, but a pain) I have heard of someone using a bunch of bungee cords to pull them in one bungee at a time side to side. It is easier with a strong helper to just push them on with a good push, but again it is tough.

Steve Stats made a quick jig out of a board. Cutting it at the carb angles to form the V-shape of the carb rack. (I have a e-mail with picture if you are interested in seeing them. jmortens@attbi.com ) He then used a set of those "Sure Grip" clamps to just EASILY pull the carbs on. REAL SLICK.

Always use a bit of motor oil to lubricate.

John

CRAZY DAVE · Post by **CRAZY DAVE** » Sun Jun 29, 2003 12:29 pm

MatC-- He is correct about getting them back on. #1. When the engine is tilted adjust all the slack into the throttle and choke cables that you can get. Tip the carbs backwards and hook the cables up first. #2. Coat the boots and the carbs with WD-40 or anything like it. Get the left carb started into the boot as far as you can and tighten the clamps on it.#3. Zip-tie the front brake so you don't push the bike off the stand. #4. Place the end of a 2x4 down between the starter and use various blocks of wood between it and the right side carbs and slowly lever the carbs onto the boots. Also duct tape the carb throats so they don't ingest any splinters. I did both my 79 and 80 like that and they have the original boots on them. Once you get the hang of it it is pretty simple. Hell, I only cussed the design a couple of hours!! Just remember- plenty of lube, a little wood, lock the brake, do the cables 1st and you will get it!!

sr71cbx · Post by **sr71cbx** » Sun Jun 29, 2003 4:36 pm

Blaine McKibbin · Post by **Blaine McKibbin** » Mon Jun 30, 2003 9:40 am

I am sure that when the Honda assembly line workers assembled these bikes, they didn't have to use bungee cords and 2X4s. Line workers are usually not allotted more than 1 minute to perform a task. When I first tried installing my carbs onto the carb boots, I grunted and groaned and cursed and tried different angles and leverage until I was sure I was going to break something. What worked for me was to spray copious amounts of silicone lubricant on the inner surfaces of the intake boots and outer surfaces of the carb throats. Then use my paint stripper heat gun to warm the intake boots and make them more pliable. Now starting at either carb #1 or carb #6 and pop them together one by one. I believe the secret is the silicone (which makes rubber very slippery) to overcome the friction and the heating of the carb boots which allows them to stretch over the carb throats very easily. If you can over come the friction of the metal on the rubber and the resistance of the rubber to stretch you have it licked. Silicone worked better than WD-40 for me and is not as volatile to heat and does not evaporate as readily. Spray on the silicone first, then line up the carbs as best you can with the boots. Then use the heat gun to warm up the rubber and the carb throats. Pop everything together before the parts cool off. Shouldn't take more than a minute. I used to hate reinstalling carbs. Now it is an easy task. Good luck and have fun working on your CBX.

Blaine

sr71cbx · Post by **sr71cbx** » Mon Jun 30, 2003 4:02 pm

EMS · Post by **EMS** » Tue Jul 01, 2003 4:05 pm

The Honda line workers also put the carbs on, before the engine went into the frame. And they put them on one by one.

Ric · Post by **Ric** » Sun Jul 06, 2003 8:15 pm

Jezzzzz...........just lub the rubber. put the rubber on the motor as far as you can get them. If the rubber is already on the carbs so be it.

Place the carb bank into position and have someone hold them there. Sit on the bike. Put a foot on each end of the carb bank. Use a towel to protect them.

Have your friend watch and guide, push with both legs. You may have to hold onto the frame. You'll hear or feel them pop in.

Shouldn't take two minutes.

EMS · Post by **EMS** » Mon Jul 07, 2003 7:53 am

I like tis method, Ric! :) Just tried to imagine what a nice picture this would make. Two guys installing carbs on a CBX

Blaine M · Post by **Blaine M** » Mon Jul 07, 2003 9:10 am

Just tried to imagine what a nice picture this would make. Two guys installing carbs on a CBX icon_lol.gif

Possible caption, "Congratulations you have just given birth to a CBR600R!"

CRAZY DAVE · Post by **CRAZY DAVE** » Mon Jul 07, 2003 11:56 am

EMS, Bout like putting a Hemi in a Bugeye Sprite. If the instructions don't sound right- Use the heat wrench and modify to fit!!

MatC · Post by **MatC** » Tue Jul 15, 2003 9:00 pm

Thanks all for the tips.

I thought about the 2x4 method many times, but I just could not picture this as a proper assembly line procedure. Besides, I was so frustrated I wprobably would have used the 2x4 in an extreme way!!

I finally used the heat gun with lubricant approach and it worked. Then to find out the two inside carbs are not working well and the cylinders don't fire at low RPM's. They will only fire when I get above 4000 rpm. Spark is good so I'm pretty sure its the carbs.

I may have to start over. At least now I know how to put them back on without losing my spleen.

CRAZY DAVE · Post by **CRAZY DAVE** » Wed Jul 16, 2003 11:18 am

MAT C. It sounds like your idle (slow) jets are plugged. You can verify this pretty easily even with the air cleaner attached. You can remove the screws that are used for the vaccum hoses for the synchronizer on the suspect carbs. With the engine running shoot a little carb cleaner or starting fluid in the holes. If it picks up immediately your idle ( slow speed)circuit is plugged. Off come the carbs. See the " Any Slow Jets Ideas" section here in the Tech Talk forum from May 17th and 18th for any easy way to unplug the jets. I had to do all of them on both my bikes so I know what you are up against. Just take your time-the end result is worth it.

Bill B · Post by **Bill B** » Mon Jul 21, 2003 7:03 pm

I have struggled with this several times and tried all kinds of persuasion. Finally, after a few tips from others, I think I have it down.

First, if you replace the boots, make sure you orient them correctly. There is a mold mark on the outside of the boot that signifies the top. I think John Mortensen or Dave Matchick clued me into that, and it does make a difference.

Second, loosen the clamps ALL the way. Loosen ALL the clamps, not just the ones on the carb end of the boot. The inside of the boot has a step that the neck ridge must get by, and you can pound away all day if the carb side clamp is not fully loose. It must be looser than you would think. Loosening the engine side clamps allows the boot to float a bit.

Sure, squirt some lube on the boots, but if you follow the above 2 simple steps, I think you will find that all you need to do is wiggle the carbs a little bit as you push them on so that the inner carbs go into the bores as well as the outer ones. Worked well for me.

Bill

79 & 82X

ICOA 2924

The International CBX Owners Association

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