carb advice?

I've been all over this site and have been through a ton of carb cleaning/rebuilding/synching threads and through the XJ 4ever catalog. There is a ton of information regarding properly straitening out your carbs, but I'm looking for a bit of a starting point.

I'm getting ready to rebuild the carbs on an 82 or 83 XJ750 maxim. What I'm wondering is what are the typical "must replace" parts that I should order? I know there will be specific parts to my set of carbs (stripped screws, broken bits, etc.), but I wanted to get a good starting point.

I've been through the catalog and pretty much every part is recommended for replacement lol. Is there a basic kit available? If not just a starting parts list would be cool.

I know this is the millionth thread regarding carbs but everything is so spread out it's tough to get your bearings. I appreciate any advice. Thanks guys.

 

good starting point is to take pics,and make notes of your carbs,proceed with disassy,making sure u use proper techniques and DONT BREAK OR STRIP SCREWS, if possible, and consider every rubber part as a must replace item. a rebuild carb kit is the internal parts of the carb bowls,and every other part is a separate item. u CANNOT replace the fuel linkage seals without breaking the carbs apart,which if u gonna do it do it right.
THEN when u get it to completely disassembled u WILL KNOW what parts need to be replaced as evidence is usually present from rusty springs to worn out screws. the carb bowl drain screws are NOT a must replace item,and neither is any hardware unless u absolutely want to do it.
THE MOST IMPORTANT PART is cleanliness of the insides and polishing the diaphragm bores. Do Not forget to replace the enrichment circuit o-rings!!

 

If you are careful and lucky, you replace nothing. This includes the needle and the bowl gasket. However, once dismantled, you can compare the various parts to each other, since there are 4 of everything. You then can buy 4 of whatever from Chacal using the XJ 4 EVER catalog.

You have to break your carbs down first to know what you need.
You have to know what you are doing before you begin.
You have to work on carbs to learn how.
It's a "catch 22"

 

It's a "catch 22"


yes it certainly is. but the brave venture where the fearful do not tread.

 

I would say that it's always worthwhile to replace the pilot screw O-rings and to put some anti-seize on the bowl drain screws.

Personally, I tend to replace most O-rings I come across, since they're generally cheap enough that it's not worth taking a chance on a leak later.

I've heard that some of the carb kit float needles are pretty bad, so buy a set from a known source. If the carbs haven't been opened in a while, you'll probably have no choice but to replace the bowl gaskets.

When I had my last set out, I also went down to Ace Hardware and got some stainless allen screws for the bowls. That made it easier to remove bowls while on the bike in case the float level needed to be adjusted.

If you're going to be disassembling all four carbs at once, definitely take a lot of pictures and use some parts bins or zip-loc bags to keep the parts separated. Make sure to identify clearly where the different jets came from because it is possible to screw an air jet into a main jet hole.

By the way, the silcone grease Chacal mentions should be available in the plumbing departement of any hardware store. Most auto parts stores won't know what it is, nor carry it.

Good luck with it.

Cheers,
Paul

 

The first thing to do, is determine if they really need rebuilt. Why are you attempting to rebuild them?

Next, is to carefully disassemble the carbs. Making note of where everything goes and keep the individual parts seperated so as to remain with their respective carb body.

Then clean and inspect everything and determine what needs replaced. There is no magic set of parts to get in advance, except for maybe float bowl gaskets.

Oh yeah, don't go replacing every rubber part unless you want to spend about $800 on your carbs. (Sorry Josh)

 

BDM the rubber o-rings IF u replaced every single one o them would cost u 60 bucks TOPS. sorry BDM maybe u should investigate and find out truth before posting. i have searched every detail associated with these carbs for 2 months BEFORE i broke mine down. my parts order list included new pilot jets (kids playin in garage knocked over my muffin tin and these DISAPPEARED) and my total cost with ALL NEW seals(o-rings,throttle shaft seals and new rebuild kits @ 30 bucks each that i already had) was 226.67. thats new o-rings for enrichment,idle mixture,fuel linkage, and throttle shaft. the rebuild kits other than anew gasket and needle seat and needle is a luxury item really may not be necessary,other than gasket. the rubber diaphragms are not a MUST HAVE unless the ones u have are damaged,and unrepairable. THAT is the only rubber item i DID NOT replace.
SORRY BDM

 

I suggest you take a chill pill and make sure of what you are posting then. You stated all the rubber parts. In addition to all the o-rings and various seals, the diaphrams are rubber and you can't buy them seperately. Those alone are over $100 a piece. Granted, it was a slight exaggeration to say it would cost $800. But you were not clear in what you were saying, and most of the advice you have given on this board has been quite shaky at best. You are like a kid that just wants to get the first word in, whether it is right or not.

I recommend you slow down and do some research, or at least know somewhat of what you are talking about before arbitrarily posting advice which either isn't accurate or doesn't pertain to the problem at hand.

I stand by my earlier post. You are the one who is lacking here.

 

this isnt a pissin contest dude. reality check. u can stick by anything u want,but i am in the middle of this project and the carbs are awaiting the new seals now. other than THAT i do know what i stated and i DO KNOW what i said......
the diaphragms piston assy's are 254 each complete assemblies. and the rubber diaphragms are replaceable ALONE.
Check your local parts supplier and see for yourself. for the sake one item u get all defensive as if i just stole your girlfriend.
REALITY CHECK,Brain function test, and a healthy dose of MANNERS are all beneficial items BEFORE YOU engage the lips.

 

Don't get mad because you post stupid advice and got called on it.

 

geez pathetic

 

I have returned from being away at my daughters wedding.

If you have a Diaphragm thats ruined ... you can get a very inexpensive set of used Carbs and take the best one.

 

then congratulations are in order,well wishes amd welcome back. we sure missed ya buddy

 

As Requested by BDM:
http://xjbikes.com/Forums/viewtopic/t=2 ... n+own.html
http://www.xjbikes.com/Forums/viewtopic/t=14692.html
http://www.drpiston.com/hitachicarbs.html
http://www.factorypro.com/tech_tuning_p ... gines.html
http://www.motorcyclecarbs.com/
http://www.xjbikes.com/Forums/viewtopic ... rt=15.html
http://www.xjbikes.com/Forums/viewtopic/t=1961.html
http://xjbikes.com/Forums/viewtopic/t=8588/
http://xjbikes.com/Forums/viewtopic/t=17449.html
http://xjbikes.com/Forums/viewtopic/t=6366.html
http://www.youtube.com/watch?v=CYgN2-96 ... re=related
http://www.youtube.com/watch?v=tR63vrfh ... re=related
http://www.timesert.com/html/bigsert.html
http://www.xjbikes.com/Forums/viewtopic ... tml#179570
http://www.xjbikes.com/Forums/viewtopic/t=1640.html
http://www.kanolabs.com/google/
http://kzrider.com/index.php?option=com ... &id=324523
http://mok.fileave.com/HitachiCarbBreakdown.pdf
that is my research project MR BDM anytime u wish just ask i will help u as well.

 

Thanks for all the great advice guys. The problem I'm having is some people are saying to wait to order parts because then I'll only order what I need and other things I've read say have as many parts you think you'll need available so things can progress forward.

While everything everyone posted is very helpful, I really was wondering from experienced carb rebuilders what are the typical problem parts/gaskets/ o-rings that absolutely MUST be replaced. I understand that until the carbs are apart there is no way of telling what needs to be done but as an example I'm a carpenter. Before I rip open a wall to fix a problem I always have the things to at least seal it up on the truck. A couple studs, a small piece of drywall, drywall screws etc are always stocked on the truck and ready to go. I suppose what I'm wondering is what are the carb rebuilding equivalent?

So far I'm gonna order a haynes manual, throttle shaft v-seals, and probably an assorted o-ring kit. I suppose I'll wait on the float bowl gaskets as someone pointed out that sometimes they aren't in bad shape. I gotta order the manual anyway to get started so I figure I'd order up whatever you guys recommend to get started.

Thanks again for all the excellent advice from everyone.

 

Do you fight with everyone, dude? Your posts are nearly illiterate and you like trolling and name calling more than answering specific questions. Nearly 300 posts in 2 months... I believe we'd all appreciate it if you would settle down, type and communicate more clearly and stop calling people pathetic.

 

I'm sure we all know exactly where you are coming from. And my earlier recommendation stands. Get a set of float bowl gaskets to be on the safe side, as they can become stuck and you may damage them getting the bowls off. Nothing else is a must replace item.

Disassemble, clean, inspect, then make a decision. I think you will find you have saved yourself a lot of money that way. The wait is going to suck if you do you need new parts, but the chances are quite good that you won't.

Also, be careful with an assorted o-ring kit. You have to make sure the o-rings are fuel resistant.

 

This is the best advice...also to consider: if you order from chacal, the parts are there in 3 days flat in most cases. You aren't going to be stuck with carbs split open for very long once you do get them open and see what you need.

I think the job of this forum isn't to write our advice like a service manual. "Replace everything" is what I'd expect to see from a Yamaha written product. It isn't what I expect to see from a forum of guys fixing up old school 80s bikes on a budget. There's a reason we all don't ride the newest and most perfect... so why act like it?

Diagnose and repair... that's what we do here. You shouldn't ever throw parts at a bike blindly. It will take everything in your wallet and more.

"If it ain't broke, don't fix it!"

 

On the O-rings, most auto parts stores stock a pretty decent variety of fuel-resistant O-rings. When I redid my BS34's recently, I just went up to the local Checker (aka Shucks, Kragen, or O'Reily) with the three sizes of O-rings I'd pulled out of them. They had all three sizes in stock, under the O-Tite brand. Ran about $4 for all of the O-rings.

Note that here I am talking about proper O-rings, not the throttle shaft seals, which are not O-rings and will almost definitely not be available from auto parts stores.

 

Thats what I like to hear lol.