Absolute FIRST thing to do for carb cleaning.

I will eventually need to pull my carbs to inspect, adjust, and clean them. However, this is a bike I ride everyday, and for the most part it runs great. Right now the only running problem is a full throttle high rpm miss, likely due to float levels or main jet size. I only notice when running it hard, like getting on the freeway or getting away from cars after I jump ahead a half mile of stopped traffic. Sometimes they try to run over me, I notice.

I also need a valve adjustment, and don't have the time or money to lay the bike up for an extended period. I like to do projects small enough they can be done in a weekend. I didn't have the time to struggle to get the shims out. No question there, I didn't try too hard and I found some techniques elsewhere.

My question: Planning is obviously the first thing to do before any work. Is pulling the carbs to inspect passages, clunk test, float levels, etc. (anything else guys?) worth it if I can't completely rebuild them right now, or should I leave well enough alone until I do.

The only reason I consider it is because my problem might be easily fixed by 1. Identifying that the main jet is the wrong size 2. ensuring the floats are at the right height 3. ensuring the main jet is clear, or at least running some carb cleaner through it. Also, I can see what it looks like inside, so I can better prioritize the full rebuild.

 

You are so far ahead of the pack with this one it's scary.......

Maybe. But "pulling the rack" (and then "un-pulling it", i.e. re-installing it) is going to take you 1-3 hours depending on your experience level. The passages can't really be "inspected" without some type of dis-assembly. Fuel levels can be checked with the carbs on the bike (assuming the bowl drain screws aren't completely stuck). Polishing the vac piston bores is easy enough to do, as is removing the emulsion tube and cleaning it.

But, by now, you're already 70% done with a "full" cleaning and rebuild. With a little extra planning, you can do the entire job...perhaps on a long weekend!


But, first things first.........check those valve clearances (weekend #1), order needed shims and replacement valve gasket (if needed) and install needed shims (if needed) on weekend #2. Weekend #3 can be spent checking fuel levels, and pulling and re-installing the carbs to do the "minor" cleaning, while weekend #4---the labor day weekend....can be spent doing a thorough cleaning/rebuild, synch, and colortune adjustment.


Weekend #5 can be spent screaming down the road like a scalded dog as you get used to enjoying all that newly-found power.........

 

[quote="day7a1"Is pulling the carbs to inspect passages, clunk test, float levels, etc. (anything else guys?) worth it if I can't completely rebuild them right now, or should I leave well enough alone until I do.

My guess is Yes. I just finished doing the enchilada to mine and I am glad I did. If nothing else, if you do what you can now and then finish the job soon, you won't have to do repeat what you just did the next time you go in to finish the job.

It'll just be the hassle of removing & replacing the carbs an extra time.

It's pretty fun!

 

LOL!

I see chacal answered as I was still typing (I type slowly...) He is one of the resident Gurus here and he also sells parts for the XJ, most everything you will need and he ships fast. Most everything I've needed I've gotten from him.

Apparently like me, he's also sometimes up very late at night...



At the very top of the forums page under "topics" you will see "XJ4Ever - Supporting Vendor" click on that, that's his page and read thoroughly in the Church of Clean. You'll also see his parts catalog and read under "New Arrivals" for more parts.

You really will find all his articles on his page most helpful to understand.

Another excellent "must" read is RickCoMatic's tutorial on carb work & that's here: http://xjbikes.com/Forums/viewtopic/t=2 ... n+own.html

His tutorial on "Clunk test": http://xjbikes.com/Forums/viewtopic/t=1 ... clunk.html

And how to adjust your clutch: http://xjbikes.com/Forums/viewtopic/t=2 ... cable.html

But you've probably been aware of these tutorials long ago but if you're not, they're a huge help.

You'll be glad you adjusted your carbs properly when you do.

 

The absolute FIRST thing you must do is read this post about carb cleaning written by RickCoMatic. You will find this man's instructions to be written clearly and easy to follow.

Once you read the article I would suggest doing the clunk test, checking your main jets and fuel bowl levels. This will require you to take the carb rack off but you will find it well worth it. If you are CAREFULL and delicate you get throught this without needing to replacing anything in result of having a thick wrist.

Keep in mind that if you are removing the main jets to clean them, they are made out of very soft metal (brass if I remember correctly) and WILL be damaged if you do not use your head about removal.

Since you have your bowls off you might as well do a spray test as well. Watch your eyes!!

Be carefull not to mess with the idle adjustment screws on the carbs when you have it off or you will need to synch them after you put them back on, though a synch wouldn't hurt either.

Hope this helps!

 

Haha, I just did the same thing KAIJ. Apparently you just beat me to the punch. Well at least day7a1 has a response team!!

 

This is the advice you NEED. Any other course of action, attemping to shortcut the process or "skip over" steps is only going to lead to frustration. You cannot properly tune or hope to accurately sync the carbs on a bike that needs a valve adjustment.

You will save time in the long run by doing it correctly and in order, the first time.

You might want to read this, too: http://xjbikes.com/Forums/viewtopic/t=24010.html

 

Chacal, or anyone else for that matter, per your suggestion on your first post, if I were to take my valve cover off to check shim heights, wouldn't I need to replace the gasket twice if I did the check one weekend and then replace shims the next weekend, if I wanted to drive the cycle in between weekends?

My understanding of gaskets is, once they are compressed they are done. So if I took the cover off again the next weekend I would need to replace it again to prevent leaks. I could definately be wrong. Or is that the purpose of the bolt donuts, to keep the valve cover tight if you were to remove the cover more than once?

This has been what has been keeping me from checking the clearances. I like to hear the bike running every few days and a trip or two around the block makes be feel good until it get it completely road legal! I figured once I took that cover off there was no replacing it until the shims and gasket were replaced.

 

The gasket, especially on a YICS bike, is made to be reusable.

The rubber donuts push the cover down against the head; they too are reusable.

Once you've replaced the gasket and the "donuts" they are reusable for quite a while; they usually need to be replaced the first time because all the life has been baked out of them.

I've had the valve cover off/on my '81 a few times since the gasket and donuts were replaced two seasons ago and always reused everything, no leaks.

On a non-YICS bike, the gasket may need to be replaced more often, but it is a lot less expensive; the rubber "half moons" are reusable.

 

If it is a fairly new valve cover gasket, it is meant to be reused. Assuming of course that it was installed properly, And didn't get damaged by a snag when removing it. If you do damage it, don't worry to much, a little RTV will get you by for the week so you can get a new one.

 

Thanks guys. And before I get started on my response, I forgot about my other question: Without drain screws, should I just disconnect the tank and let the bike run out of gas to drain the carbs before removal? Seems like a silly question, but removing the fuel isn't really mentioned. Rick says to pull the gas tank...but not to drain the fuel. Maybe it doesn't matter?

Anyways: My drain screws are not coming off on the bike. Someone else has already tried. That check would be done by now otherwise.

The valves are pretty much all .008 mm tight, with the exception of 3 being no more than .045 mm tight. Would that cause that full throttle high rpm miss?

I honestly haven't troubleshooted it thoroughly, it feels like a lean miss when I'm really on it, so I can't imagine what it would be other than a fuel supply issue. I haven't tried it with the Fuel Enrichment Circuit on, for instance. I guess it could be missing if the valve is floating at that speed and power. It's not a petcock issue. I know that.

Chacal: I already have a list of items and part numbers and prices, ready to go, from you if I can but really from whomever for whatever I need. I have a 5 sheet excel document of plans for the motorcycle. I'm just stuck right now until I get enough funds. My shims are stuck in there pretty good. You certainly answered my question. Yes I should pull to inspect, but not until the valve clearances are complete. Thank you.

Fitz: I've read your philosophy on restoration several times. I do realize that doing things in the wrong order might necessitate more work overall, but my theory of proper troubleshooting is this: Priority goes to the most effective fix for the lowest cost, safety being priority #1. That's why a complete carb rebuild is out the question right now. Ineffective (until valves done) and high cost (I doubt it's immaculate). Honestly valves are only 3rd on my list due to the high cost. New Brake lines are #1, and some paint/corrosion prevention on my tank is 2nd, b/c it can be done cheap. For what I want, real cheap. And is pretty important since I can see the ocean from where I park. Pulling the carbs and looking for information is real cheap too. I may have good float levels and the right jets, but I get the STRONG feeling these carbs did not come original on this bike. I think they've been messed with.

Zyggy and KA1J...yeah... you put something haughty about cleaning carbs in the title you're sure to get a quick response around here. I try to not post frivolous inquiries, but nowhere in the posts about cleaning does it say "now, go put your unfinished carbs back on your bike so you can go to work in the morning". I need to know where that step belongs for me. Now it does.

Zyggy: I've had the cover off, and if you read the chacals catalog and ricks post it certainly appears that the gasket is a reusable rubberized metal type. From what I can tell, as long at it's in good condition you can remove and replace without destroying it.

 

The point is this: You already KNOW your valves are tight, you said so yourself.

Running a motor with tight valves is playing Russian Roulette with a burnt valve. Wait long enough to adjust the valves and just an adjustment won't help; you'll need a valve job.

A valve adjustment isn't expensive; it is a rather time consuming (and admittedly daunting for a first timer) task. PUT IT OFF, just fix the bike and ride it, and you WILL eventually burn a valve and won't be riding until a LOT MORE time and money are spent.

It's not a matter of most effective fix for the lowest cost; it's a matter of putting off what is right now a small "maintenance" item becoming a much bigger "rebuild" situation simply because it was put off.

The most effective fix is the small one that saves you big ones down the road. You need to re-prioritize, or risk damaging the motor. Riding it with tight valves is asking for big trouble.

 

Thanks for the information on the gasket, now I need to beg my finacial advisor *cough*wife*cough* for a charitable donation for a man in need.

 

I think you may have missed the "Priority" part. I'm not putting off work, I'm planning to be more effective within my budget. I can't do it all at once. It ALL has to wait, it's just a matter of how long.

That being said, I take it you would give priority to a valve adjustment over a brake line replacement? That's why I put the Safety is #1 in my theory. I don't think we disagree on the rest of it, because the tank painting I can do in the same weekend as the reading of the shims and brake line replacement. It's not a time killer. I don't care how it looks, it just needs paint. I was going to do those next weekend.

Brakes line: Safety issue, ergo #1.
Tank painting: Very low cost, in terms of both time and $, medium priority, ergo #2
Valve Adjustment: Very High Priority, Very High Cost in terms of time and $ (I calculate about $110 and two weekends).

Really, the tank painting and valve adjustment will occur concurrently, as I have to read the shims before I can order the right ones. Maybe the valve adjustment is also very high safety, that seems to be what you are saying.

 

actually the very first thing you need to do is measure get the angles and levels of the carbs before you even pull them so you can set them set up correctly to set you float levels very important. just thought i would throw that in will save a bunch of time r&r the carbs

 

The carbs get their float levels checked and adjusted when perfectly level, side to side and front to back.
Most easily accomplished with the rack off the bike; I mount mine in my bench vise and get it dead level.

day7a1 I wouldn't ride the bike with tight valves NOR would I ride it with bad brakes. Yes the brakes are a primary safety issue but there's no sense burning up the motor in the process.

 

i guess the 550 is different then my 700 my carbs angle slightly forward. should work level i just like to be perfect . i guess its from working on all the v twins

 

After consideration, I have decided that there is no need to lump the gasket replacement together with the valve adjustment, saving me (temporarily) enough money that the valve adjustment can be bumped to #1 priority.

I can do the brake line and valve adjustment at the same time. They aren't bad brakes, they could just be better brakes. I have about a $100 per month budget. I figure that would be a bike payment for a new bike, if I could find one I liked! And I don't expect that to go for 60 months straight.

That makes me feel better, I don't like running tight. Now to get those shims out!