How to remove / install carbs ...

I don't know about the rest of you, but I find the single most frustrating aspect of these bikes is the difficulty to be found removing/reinstalling the carbs.

I thought that some of you might benefit from some of my experiences in this regard with some tips I have found very helpful, particularly on reinstallation.

First, the phillips head screws on both the manifold boots and the intake boots are prone to stripping unless you are very careful. If you remove one and take it to your local hardware store, you should be able to get 8 replacements with allen heads. The ones I got need a 3mm allen "wrench". I recommed getting either a "screwdriver" with the appropriate allen head or, if you are like me and use something like a Skill Twist, an allen head driver of the same size. I also recommend adding a washer between the head and the clamp to avoid any problems of the head pulling through the one side of the clamp.

Second, the Yamaha instructions for removing state that you need to push the boots into the airbox when dismounting. As far as they go, that does work well. The bands around the boots can be a bit of a problem so I have found it helps to remove them before removing the carbs. If you have the carbs that have a separate link cable between the throttle and the carb (like the 550's) then be sure to keep track of that when removing the carbs. It is easily lost.

Installation, however is a royal *itch. Yamaha says that when remounting, leave the boots shoved into the airbox and then pull them out and over the carbs. I have yet to find a way to put enough pull on the boots to get them out of the airbox. Between the large size of the ribber ring that is supposed to prevent the boot from going into the airbox and the lack of room to reach down/in/ and get ahold, I have not found a way to accomplish this task. Here is the alternative I have found. Unfortunately, this will only work if your boots are reasonably pliable ...

With the boots totally removed from the bike insert the carbs and connect the throttle cable (choke too if it is in the miiddle of the carb rack). It will not yet be seated in the part that provides tension, just loose in the connecting hole.

Insert the carbs into the manifold boots.

Now, the boots need a small amount of lubricant (I use silicone grease) on the airbox side of the first ring that goes into the airbox and in the channel between the two rings. The first application greatly helps with getting the boots into the airbox. Now, install the boots, working from the inside boots out. Bring the boot up from the bottom, squishing/bending/smashing the rubber so that you can get it lined-up with and inserted into the airbox. Usually, this leaves the carb side of the boot kind of squished and not exactly centered on the carb. This is why the grease between the two rings. It is easy enough to get the rubber near you properly over the carb, but the rubber on other sides is very hard to get to and pull over the carb. Having greased the groove, however, you can turn the boot fairly easily, allowing you to rotate and pull the sides around the carb, eventually shoehorning it over the carb all the way around.

Having completed this task on all four carbs, Now there is the challenge of getting the airbox close enough so that all the boots are comeletly on. I have come up with a great method to pull the airbox onto the carbs. Rather than using the Patented install tool (the wooden hammer handle), use a set of bar clamps to pull the box firmly against the carbs. With this in place, proceed to bolt the airbox down so it can't choose to reverse course.

It is at this point that I actually install the clamps on the boots. Fully removing the screws, I open the clamp and place it place where it is supposed to sit, then screw it down.

There can still be moments of stress and cursing, but I have found this as the easiest way to go about this task. I would be interested in hearing if any of you have been able to successfully pull the boots out of the airbox per Yamaha's directions, and how you accomplished this feat.

Other suggestions?

 

My boots are very pliable - Just start at the inside and pull the boot through and line up the little pointer. Not easy but not real hard either. Then I use a tool like Rick suggests, mine is a partially straightened spring hook, to seat the boot around the carb.

It can be a royal pain.

 

My hands are too big to get in under/around the boots on the "inside", so rotatng the boots is the only way for me.

 

I understand on the Xs and on my XS400 they are shorter and a real pain. You have some really good ideas.

Are you using the bar clamp to seat the carbs into the manifold? That sounds like a good idea - what are you pulling against?

 

I can only speak in regard to 550s: Originally I too pushed the boots into the airbox and also found this to be a real pain.

The 550s airbox comes loose and slides back almost 2" to help accomplish the task. There is a third screw under the tool tray (the other two are obvious) that needs to come out.

I have started just leaving the boots on the airbox and sliding the whole mess back far enough to get the rack in and out of the intake manifolds. It's much easier doing it this way, the airbox boots just "mash" out of the way on reinstallation, and once the carbs are seated in the manifolds, putting them back on isn't that big of a hassle since they're halfway there.

 

I have found that hitting the carb boots with the heat gun for a couple of minutes makes the job at least 75% easier for me.

 

I'll have to look for that third screw, because with only the two in the front, it didn't move back far enough to allow carb removal - at least not on the Maxim. Fitz, yours is the Seca, right?

You could use the bar clamps to seat the carbs in the manifold, I guess, but I can get those in by hand easily enough. I used them to pull the airbox to the carbs and to hold the boots over the carbs while putting the clamps in place and tighening them down. That way I wouldn't have the problem of the boots or clampls sliding off while trying to screw the clamps down.

I clamped the backside of the airbox over to the front side of the carb bowls. You have to do it right or the clamp slides up the airbox and comes off. You have to have something against the airbox so that the clamp doesn't slip. A piece of soft rubber works great for this.

You could also use the bar clamps to get the carbs out of the manifold boots by clamping against the frame behind the airbox and then the same point on the carb bowls.

 

I must be real lucky,cause mine are a piece of cake.They're soft and pliable so I just loosen the clamps and pull them right off.No messing with shoving them inside the air box.

 

+1 on the bar clamps! I use a pair of the "squeeze handle" type clamps to mount my carbs to the manifold boots. The contacting surfaces of the clamps that I use are a plastic that does not mar the metal. As for the air box boots, mine are plyable enough not to cause me any real heart ache. I just did replace them with a set that I found on eBay. My old ones were super stiff.

Not to high-jack this thread but, is there a product out there that will soften the old boots and, return them to a more usable consistency?

Cheers
Ken

 

Removed and re-installed my XJ750 carbs on the weekend - pulled the rear boots into the airbox, removed the carbs, then pulled the boots completely out of the box.

To install, put the carbs back on, hit each airbox boot with a heat gun until they were soft (wore my welding gloves), then put them back on one at a time (starting with the middle ones). Much easier than I expected :lol:

 

Yep.

Yours has the third screw too; lift up the tool tray and you'll find it. I take the two top ones completely out, that doesn't restrict my ability to move the airbox due to their straight tracks.

With two of these, I've gotten pretty good at yanking the rack; if you take all the airbox screws OUT it gives you a lot more wiggle room.

Once again; my experience in this matter is limited to the 550 Seca.

 

Ken, I left mine in WD40 overnight and now they're soft, well I had to 'kneed' them the next day but they're still soft 4 months later

And since I didn't have enough WD on hand to waste, I had them wrapped in a rag for a whicking effect and only about half way soaked in the WD, then after 8 hours, I turned them upside down

 

Thanks Fritz, will remember for next time.

I'll have to try that WD 40 trick. The local auto parts store has it available in bulk liquid form rather than spray. I have at least 12 of them that could use a good soaking.

 

Is this for the carb to head boots or the carb to airbox boots ???

 

It shouldn't matter, rubber is rubber. But I believe he is referring to the airbox boots rather than the manifold boots. That is what we were discussing above and most people avoid the manifold boots like the plague as you are likely to end up with a bolt or two that shears off during attempts to remove.

 

yeah it was carb to airbox boots and YES I avoid my manifold boots like the plague