to rebuild or just clean carbs

So my '82 xj650 seca is running ok. It idles rough but seems to run strong otherwise. The bike has not been sitting for years like some others.

It does need a little work and I am trying to do so on a budget...so the question is, should I pull the carbs and give them a good cleaning, inspection, and sync (doing valves too) OR do I spend $70 and get the rebuild kit from chacal? It seems like a lot of money for not a lot of parts...

I've read varying opinions. Can BigFitz or Rick chime in here?

 

Before tearing things apart and spending money, and before it snows, try this - -
Turn your Pilot screws in, lightly seated, counting the turns and write this info down. Doing this will "disturb" any crud in the needle location.
Re-set the Pilots as they were.
Fill your tank with name brand gas. Add exactly 1 OZ of Acetone without spilling any on your paint.
Go for a fast ride, burn the tank, refill.
Proceed with any needed Pilot fine-tuning.
(This assumes your valve clearances are in check, and you are in sync, and you have no electrical gremlins)

 

I'm fine with piling stuff apart and cleaning. The bike isn't rideable anyways right now so that isn't an option.

 

Plus the carbs are already off the bike.

 

TIME is right; (although running solvent thru rarely helps)

Tear down, clean, inspect. Then order the necessary parts.

You won't know the condition of the float needles, for instance, until you look. You may only need a few o-rings and gaskets. I've had float bowls come off clean, leaving a perfectly reusable gasket before too; that's why it's better to take the "studied" approach. I've also seen carbs where virtually everything "perishable" needed to be replaced.

It's not necessarily an expensive proposition, unless you take the "shotgun" approach. Not recommended.

 

I think I will take your advice and do the studied approach. I pull one of the bowls and the gasket is still good, so i'm just going to get them cleaned up and order parts on an as needed basis and then tune it.

 

If you have trouble with them or getting it running give me a shout. I go through York on a fairly regular basis in the winter. Hello Roundtop, now if it'll quit raining and get to snowing.....

 

carbs rarely need rebuild "kits" they're just for dummies that think new is better, when they dont take the time to clean the carbs, like fitz said, plastic and rubber bits may need to be replaced but those arent included in the kits

make sure to clean out every hole in you emulsion tube.

 

Pulled the carbs apart last night. I have to replace the main needle since it's mushroomed but everything else seems ok. Had to drill the pilot covers but the screws came out fine. Not sure if I'm breaking the rack yet or not since most looks good.

 

i am doing the same thing wrxg33k. I've got a christmas break coming up once this semester of school is done and I already have the carbs almost ready to break apart. thinkin maybe I'll boil them in lemon juice or something too to make them look pretty. hoping Len sells individual items like new pilot jets and one or two gas filter/screens (the half sphere filter that is in the bowl, what's it called?)

 

spending a friday night inside discovering all the nitty gritty details of carbs and wanted to bump this thread. my next question is this: What is the difference between 'main' fuel & air jets and 'pilot' fuel & air jets. thanks to Len's catalog of detailed information selling all these parts i've found out the air jets are backwards in the manual picture but the only question I still haven't found is what the difference between 'main' & 'pilot' is
reminder, like my signature says, i just want to be able to explain this stuff to somebody who doesn't even ride bikes. thanks in advance

 

OK, without getting too technical:

Main Jets and Pilot jets perform the same basic function but at two different degrees of throttle opening.

The pilot jet is responsible for fuel metering in the first 1/3 to 1/2 half of throttle opening; as the throttle opens further and the needle gets right up out of the way, the main jets take over.

Fuel jets and air jets perform slightly different functions, one metering air one metering fuel.

DON'T SUBMERGE "whole" carbs in anything, including lemon juice.

Each carb has throttle shaft seals on both sides of it, behind thin nylon washers. You cannot remove the throttle shafts without removing the butterflies which requires advanced surgery and is not something that should be undertaken unless necessary. If you submerge a carb that still has the throttle shaft installed, you run a very real risk of trapping your solvent of choice in the throttle shaft seals, with potentially negative results (like ruining perfectly good seals.) If you're not breaking the rack and FULLY disassembling the carbs you can't submerge them.

The outer throttle shaft seal on any carb can be inspected by carefully removing the clip and nylon washer, and gently wiggling the seal out. You can inspect the ones that can be easily gotten to as an indicator of what the "trapped" ones probably look like.

The "beanie" screens inside the carbs can simply go away. They're only there to clog up and infuriate you; run an inline fuel filter and don't fret it.

 

On th topic of th 'beanies' filters/screens, I've still got th originals in mine and they've never been a problem, tho with th intank and inline filters they could be irrelevant..

 

okay I didn't realize those 'beanies' weren't necessary if a fuel filter is present as well but makes sense. i had seen somebody else's rack without them and wondered why theres didn't have them. if one or 2 of them or missing or deformed, should the good ones be removed as well or doesn't it matter? i wouldn't think so but thought i'd ask the experts

the only reason for me to break the entire carbs apart from the rack would be to change the throttle shaft seals. i can't look at the seals from the ends right now since I'm back at school 2 hours away but if those look decent, would there be any other advantage to having the carbs fully apart? fitz, you've gotten me wondering if taking the butterflys off and boiling the carbs in lemon juice is really worth it...? i even remembering fitz telling sodacubes that you wouldn't suggest it unless absolutely necessary :?

boy the philosophy of restoration 101 fitz has written sounds great, and i'm trying to "get in control of the process" before it controls me without having done much work on the carbs yet. my christmas break is coming soon so I just thought I'd prepare myself beforehand

 

Nice bike ... I tried to buy it on CraigList Lancaster, but guess you got there first. I have an 82 Seca also. Make sure you check out this post
Doing this in addtion to cleaning other parts fixed by starting problems
No need to break the rack in IMHO.
http://www.xjbikes.com/Forums/viewtopic/t=8918.html

 

xjazz, its a small world.

I've actually already corrected the starting issues and some other odds and ends. I'm cleaning the carbs for performance issues, it idles rough so I'm doing the carbs and checking valves etc. Its a great bike though!

 

OFFTOPIC:
That "DAMN YOU YAMAHA" picture from the How to Clean the enrichment circuit post, that was just mentioned, is both entertaining and so very true.

I too felt like crying when I got that gear in my eye I have to say... I really don't want to try or do that again.

You won't find my goggles too far from my face when working on the bike now-a-days. Safety first for sure.

 

You can "Blow-Out" the Brass Siphon Tube by taking a piece of Heat Shrink that fits over the Tube ... and 'Shrinking" its end over the Carb Cleaner's Red Tube.
Helps clean all the passages.

Don't lose a lot of time Cleaning the Fuel Bowl Enrichment Well.
Buy one or two New Drill Bits from chacal.
Drill the Lower Inlet and the Enrichment Well.
Once the Ports are reopened; Clean and Blow-out.

{If you use a Power Drill. Before you Chuck the Drill Bit, ... MEASURE how Deep you want to Drill and TAPE the Bit from going further.}

 

I really don't recommend it unless absolutely necessary. Yes, there are a lot of cases where it is necessary; but in a lot of cases it's not. I've seen throttle shaft seals that looked like a series of disconnected dried rubber hoops, and I've also seen apparently perfect ones in GRUNGY carbs.

My point is, unless you're being REALLY thorough, or have some good reason to do it, removing the butterflies is best left alone until it is truly necessary. I certainly wouldn't do it for purely cosmetic reasons. Problematic throttle shaft seals can generally diagnosed using an unlit propane torch; otherwise it's a measure of last resort.

And I would also avoid doing anything that forces the issue, like submerging the carbs and trapping something in the seals.

 

fair enough fitz. think I'll plan to just polish the bores and what I can reach without breaking the rack.

wrxg33k.. sorry for hacking your thread.

 

No worries!

Today I got the entire rack cleaned and bowls cleaned and enrichment well cleaned out. Next up is polishing the bores. With regards to that, I plan on starting with 800 grit and working up to 1500 on the bore and using some 1200 grit on the diaphragm piston itself. All sanding will be done with wd40 a's lubricant. Does this sound like the best plan of attack for polishing the bores?

 

The Diaphragm PISTON needs very little care. Most are sufficiently cleaned with a light polishing without abrasives.

Excellent results cleaning the Bores is achieved with ScotchBrite Pads (Gray and White)

Polishing takes a Polish Compound of Rouge.