Opinion Poll - Carb Re-build Kits

[Roostabunny]

I've heard one opinion that says carb re-build kits aren't worth the money. I'd like to believe that, as it'd save me a bunch of money and I'd rebuild the carbs a lot sooner, trading in elbow grease and time for the cost of new jets.

You guys agree or disagree? Other opinions?

Hopefully this won't turn into a row like oil threads do. :-D

Also, once I have the carbs pulled, about how long does a re-build take? This'll be my first time and I'll be reading the GSR carb series as I go, so I'll figure on double the normal figure assuming no problems.

 

[waterman]

I have had great results with just cleaning carbs and reusing existing jets. Make sure to pick up a set of orings from Robert Barr
http://www.cycleorings.com/ and take time to thoroughly clean carbs.

Generally, I can get through a set of carbs in two hours. Most of the time is spent dipping carb bodies. I give them a 20 minute soak with a toothbrush scrubbing when they come out. This usually cleans up any big deposits and leaves them spotless. I assemble after a water rinse and air dry, while another soaks.

First time through, take your time and make sure you have screwdrivers that tightly fit your jets. I have customized an old screwdriver with bench grinder to better fit pilot jets. Also work on one carb at a time, place carb and parts into plastic sandwich bags to keep small parts together. They can seem to be daunting, but with patience you can take them apart and put them back together again.

 

[TheCafeKid]

I too clean them rather than buy rebuilds...from what ive read often rebuilds use subpar jets and that can cause problems..Definately get a set of rings for your carbs from that site he suggested. Robert Barr is very quick with getting them to you and they are a great price. While you're at it, change your intake boot rings too, he has those as well, and he also has hex head bolts to replace your boots stockers, as they are a royal PITA to get out sometimes. ( I got lucky) If your're doing your carbs its silly to think your boot rings are ok too...i neglected them and ran myself in circles trying to figure my carbs out, and a good part had to do with the fact that my intake boots (well one anyway for sure) were drawing air..you'll never get your carbs synced if this is the case.

 

[Nessism]

Most of the time you can reuse the brass jets you have in there now. Even if they are corroded on the outside, most of the time the orifice is fine.

You can really rack up some money in parts if you need to start replacing float needles and seats. In a case like that, I'd order a kit. I've got some K&L kits and the quality looks good - made in Japan. And it's nice to have new gaskets, particularly the float bowl gasket. Unfortunately, the kits don't come with the O-rings for the carb to carb interconnection plumbing thus you had better order one of Robert Barrs kits anyway.

Regarding how long it will take, figure on a complete day on the weekend. Maybe two days spread out; depending on how dirty the carbs are you may have to soak each one for quite a few hours before they come clean - no way to hurry that process.

Good luck.

 

[Roostabunny]

I too clean them rather than buy rebuilds...from what ive read often rebuilds use subpar jets and that can cause problems..Definately get a set of rings for your carbs from that site he suggested. Robert Barr is very quick with getting them to you and they are a great price. While you're at it, change your intake boot rings too, he has those as well, and he also has hex head bolts to replace your boots stockers, as they are a royal PITA to get out sometimes. ( I got lucky) If your're doing your carbs its silly to think your boot rings are ok too...i neglected them and ran myself in circles trying to figure my carbs out, and a good part had to do with the fact that my intake boots (well one anyway for sure) were drawing air..you'll never get your carbs synced if this is the case.

You bet - I found the o-ring problem the first time I tried to sync. They were like uncooked spaghetti. Snapped one right away, couldn't find a replacement that night and then commuted with a 3000rpm idle for about a week. In August! Painful. Same experience with the phillips-head screws, too - my buddy did a trick with a chisel to spin the last two off - lucky. Anyway, when I got it fixed (and finished syncing) I replaced them with NAPA o-rings and plain steel hex bolts. Rookie mistake.

So, attempt #2 - My real o-rings and sparkley stainless bolts from Robert Barr arrived today and go on tomorrow.

 

[TheCafeKid]

You bet - I found the o-ring problem the first time I tried to sync. They were like uncooked spaghetti. Snapped one right away, couldn't find a replacement that night and then commuted with a 3000rpm idle for about a week. In August! Painful. Same experience with the phillips-head screws, too - my buddy did a trick with a chisel to spin the last two off - lucky. Anyway, when I got it fixed (and finished syncing) I replaced them with NAPA o-rings and plain steel hex bolts. Rookie mistake.

So, attempt #2 - My real o-rings and sparkley stainless bolts from Robert Barr arrived today and go on tomorrow.

Also...as ive just discovered tonight..be EXTRA mindful of your float level when you set them..i wasnt and rushed thru it. I also used inferior tools (read..a ruler..heh) to set them...today i purchase some calipers and went thru them again and low and behold my 2 and 3 carbs were WAY off..like 3 mm, gee i wonder why i still smelled rich and my fuel line kept emptying...Also a ROOKIE mistake for me, as this is MY first real attempt at cleaning and tuning carbs too...ive messed with some CVs on my yammie, but never really adjusted them...learning as we go..its fun isnt it? can also make you loopy on bus fumes...

 

[hampshirehog]

If you're running a stock set up and don't need any bits to correct for pods / exhaust I can't see the need for buying a kit in most circumstances. Supposedly jets wear in time but I've never seen this in action - even on very high mileage bikes. Rubber rings can go brittle / crack / split but you can usually find the correct replacements singly.

The only thing I think about buying is gaskets. It's fiddly and time consuming to make float bowl gaskets, though I do usually end up making my own (quicker than waiting for the postman).

And personally I wouldn't buy a Dynojet kit, even if I was changing from stock. IMHO you hand over a lot of dosh and get very little in return and you can generally work things out for yourself a lot, lot cheaper.

Wally

 

[Nessism]

If you're running a stock set up and don't need any bits to correct for pods / exhaust I can't see the need for buying a kit in most circumstances. Supposedly jets wear in time but I've never seen this in action - even on very high mileage bikes. Rubber rings can go brittle / crack / split but you can usually find the correct replacements singly.

The only thing I think about buying is gaskets. It's fiddly and time consuming to make float bowl gaskets, though I do usually end up making my own (quicker than waiting for the postman).

And personally I wouldn't buy a Dynojet kit, even if I was changing from stock. IMHO you hand over a lot of dosh and get very little in return and you can generally work things out for yourself a lot, lot cheaper.

Wally

It comes down to how much value you place on your time. I've made float bowl gaskets in a pinch but for $3 each, it's a huge waste of time if you can just plan ahead and order them. Regarding O-rings, most of these are very specific sizes and not generally available at the local auto parts/hardware store. For use with gasoline, Viton material O-rings are recommended as well which most certainly won't be available locally. It's far better to purchase an O-ring kit from someone like Robert (not sure if he ships internationally though). My opinion as usual.

 

[Dave8338]

I ordered the kits as the float gaskets were toast by the time I got things apart. Didn't use the mains but did use the pilots as those that were in there, had been trashed by someont in the last 25 years. Also had to get the fuel tee o-rings seperate...local dealer.

If your carbs look good and unmolested...I'd buy the o-rings from Robertbarr and put things back together.

 

[Muser3]

carbs

carbs

I agree with the idea that kits are not routinely needed. Cleaning is usually what's needed since jets and valves rarely wear out. I have reused bowl gaskets but prefer not to. The o-rings from Robert Barr are a good way to go. If the valve needles are marked, I replace the valve, and have had good results with inexpensive valves.
After the floats are set, it's a good idea to use a tube in the bowl drain and set the level precisely before the carbs go back on the bike.
Lee :-D

 

[adrjunky]

To me the term rebuilding is misleading.The only parts that show any appreciable wear are the float needles and seats. If other parts are showing wear like slides and needles that's a totally different matter.As for gaskets and orings yes they should be changed but not frequently (ie when they get hard if brittle you waited too long). Anything else is just about cleaning and a result of improper storage.Carb parts cleaning is best done in a solution just for that purpose and overnight works well.

It's like the best offence is defense store your bike properly... drain carbs , fill tanks change oil and remove battery. Geez i sound like my mom sorry.....

 

[bwringer]

I actually did waste $100 on carb kits, when I was young and foolish. I also wasted months of time and lost untold miles of riding time before I figured out that the shoddy junk in the carb kits was the source of my problems.

Don't waste your money -- the parts in the kits are incomplete, and filled with nothing but inferior, disgusting, shameful, evil, slimy junk. If you look closely, you can even see with the naked eye that the parts in a kit are nothing but very poor copies of the original parts.

The only parts that are remotely usable from carb kits are the float bowl gaskets, and these can be had separately for $3 or $4 each. If you decide you need needles and seats, buy new OEM.

Even carbs that are absolutely disgusting can be successfully cleaned and rebuilt using only the directions in the carb cleanup series, a $12 o-ring kit, and possibly a $16 set of float bowl gaskets.

Also, I would repeat the advice given above to replace the intake boot o-rings and intake boots while you're at it (use the money you would have wasted on carb rebuild kits).

You also need to be aware that float height is a critical adjustment -- take the few minutes to get this exactly right.

The manual is quite misleading -- it simply gives an acceptable range, but this is not nearly good enough. A 1/2 millimeter adjustment to float height makes an easily perceivable difference in low-midrange running and throttle response.

Each float must be set exactly the same, and both sides of the float must be level and set to identical heights.

My carbs ended up 1/2mm below the range given in the book. (Since float height is measured with the carbs upside-down, this raises the fuel level slightly with the carbs right-side-up, and creates a slightly richer mixture in the just off idle to low midrange area.) You have to experiment a bit, even with bone-stock airbox and exhaust.

There are other common errors -- on CV carbs, you sometimes find that float heights have been set using the top of the float instead of the "step" in the float.

If the float needles and seats have been replaced with the typical shoddy aftermarket crap, you might also find that the springs inside the needles are weak. This allows the float to sag when the carbs are upside-down, and makes it impossible to set float height accurately.

And even with OEM needles and seats, you have to re-measure and re-set float height any time you disturb or replace the needles and seats.

Also, valve clearances must be correct -- incorrect valve clearances will affect carburetion badly. Do not skip or defer valve clearance checks -- valve clearances are a lot more important than most people think. Checking and adjusting valve clearances is also a lot easier than most people think.

 

[spyug]

I think carb kits are overrated and over priced and as some have said it is seldom necessary to replace all the parts in the carb when you do a clean / rebuild.

Jets seldom wear out but can be plugged to the point of being unable to be cleaned and thus need replacing. More commonly, I believe, jets get ruined by agressive cleaning with hard picks which enlarge the orifices.

In my experience, floats can be a problem. The old brass type can develope pin holes which cause them to lose buoyancy. These can sometimes be repared with a smear of solder or epoxy paste. Plastic floats also have been an issue for me as the plastic deteriorates and can start flaking off. The only solution is replacing them.

Float valves are also an issue from time to time as wear can develope between the steel needle and the brass seat allowing gas to flow past even when tightly seated. This can result in the dreaded carb leaks into the cylinder and is the cause of bikes that sit for any length of time getting gallons of oily gas in the sump.

Float bowl gaskets should be changed out if there is any seepage or the gasket is torn when removing the bowl .If it comes off cleanly, it can be resurected and used over...just smear a little axle grease on both surfaces.

As much as possible I believe in cleaning and reusing all parts but if it is necessary to change something then OEM is the way to go.

My 2 cents.

Cheers,
Spyug

 

[Big N daft]

It's far better to purchase an O-ring kit from someone like Robert (not sure if he ships internationally though)

I can confirm that he does indeed ship internationally and he does his best to make sure you don't get lumbered with duty should the customs look to closely. He's fast and reliable as well as inexpensive!!!!!

 

[Muser3]

carb kits

carb kits

This thread has evolved a bit, but it's all good stuff.
It's been said before but perfectly adjusted and jetted carbs are one part of triangle the other two parts are spot on valve adjustments and spot on ignition timing. Two out of three ain't enough, but it's a good start.
Lee :-D

 

[excesses]

BS34 Carbs

BS34 Carbs

I have what I think is a 79 GS400 (having a tough time id'ing it). It has Mikuni BS34 carbs I believe. Where would I get gaskets? I have dealt with MikesXS with my Yammy xs650s and the carbs are BS34s on the Yammys too.

Has anyone used the gasket kits from MikeSX on their GS400?

Thanks

DJ

 

[Guest]

I've used the K&L kits with good luck. I only used the float valve, float seat, gaskets, pilot jet plug and o-rings. They are incomplete and I have used Mr. Barr's o-rings on several occasions.

 

[82Shafty]

The only bad part is that OEM Suzi only sells needles and seats as a unit. You simply can't buy just the needle. At 20 something a pop it gets expensive.

I wonder if that is my dad's problem... I threw in four needles from the partsnmore kits because his factory needle springs had rusted in the stuck out position.

My bike, however, runs strong so I was going to compare my needles to his aftermarkets to see if there is a difference... I should be doing this in the next few weeks to see if I can measure a spring tension difference.

 

[chuckycheese]

"O" rings

"O" rings

All I ever change is the "O" rings...except the first time, I changed the jets because the last guy used a kit and put in the wrong size jets.

 

[82Shafty]

The only bad part is that OEM Suzi only sells needles and seats as a unit. You simply can't buy just the needle. At 20 something a pop it gets expensive.

I wonder if that is my dad's problem... I threw in four needles from the partsnmore kits because his factory needle springs had rusted in the stuck out position.

My bike, however, runs strong so I was going to compare my needles to his aftermarkets to see if there is a difference... I should be doing this in the next few weeks to see if I can measure a spring tension difference.

I just wanted to do a follow up with my findings.

OEM needles and seats are well worth the money; there is a huge difference between OEM and aftermarket needles.

After new needles and seats and new RB o-rings, the bike screams.

I was so impressed I just tore down my carbs to install another RB o-ring kit.