Now it is the Carb!

[kycaveman]

Ok, Here we are again, had the carbs off and cleaned them up good, but did notice the diaphagms are pretty much shot, so I am looking around the net and come up with a price of $57.00 each, does this sound right?? Holy **** that is about $240.00 plus shipping. Guess I know where my Christmas money is going So this is what is going on, the bike starts right up, idles fine, but when you go to rev it up, it falls flat on its face and sputtures, does this sound about right for a diaghagms issue Ok, guys let me have it, I need all the help I can get....... Thanks in advance

[GeorgeS]

Thats about right! Actually list is much higher.

I paid $85 each 2 years ago.

 

You might find them a few bucks cheaper. However ??

 

Be sure to replace the Very Small O-ring at botttom of each Carb cover. I missed one on reassembly, caused some problems.

 

Check out your Idle mix adjust needle valves also. I reccoment useing liquid wrench on them of similiar product. Be Very Carefull of the Fine Threats here.

 

I would be interested to know, how your Float settings were found to be. All the same ? or not all at same fuel level.

I have to check mine soon.

[hipshot]

i have a question , george.

if the floats are pre- set at the factory, and have never been tampered with, can they "get out of adjustment"on there own???

just jt

[Venturous Randy]

If you would like to do a patch on the diaphragms before you decide to do the big purchase, there are several options available. I have had good results out of a product called "Liquid Tape", that you can get at about any hardware store or even Wal Mart.

The trick on using this is in the preparation. You will need to get both sides of the diaphragm real clean, like with brake parts cleaner and alcohol. Take something that comes to a point, like a scribe and put the Liquid Tape on both sides. The next step is to let this stuff dry real good before reassembling. This is the trick to having it not break down with the gas fumes. Laying out in the sun for a while works good.

I have tried several different things like silicon and Yamabond, but this stuff is the only thing I found that stays plyable and stays on.

RandyA

[GeorgeS]

i have a question , george.

if the floats are pre- set at the factory, and have never been tampered with, can they "get out of adjustment"on there own???

just jt

 

Logicaly they should be OK. However I have read a few folks say that upon checking them, they were Not all set the same. Floats that is.

 

This also goes for the Idle mix adjust screws. Mine Idle mix screws were NOT all set the same.

 

Resetting them to 2 1/8 turns, and resync made improvement.

[kycaveman]

Thanks for the info and tips, I will be trying the liquid tape trick (I actually have a can at the house), since it will be a little bit before I get the extra cash to purchase the new dia's, But I will be ordering them for sure... The outfit I found the price of $57 is http://metricpartsdirect.com/Default.asp I have ordered from them acouple of times, and so far they have beat everyone else I have found. My local dealer wanted $93 each. Talking about a mark up!!!.

 

Also, just to be clear; the Idle Mix Screws you are reviering to are the factory preset screws, you have to drill out correct? My have been drilled, but I did not touch them out of fear the great cycle gods would come crashing down on me . So if all i read is correct, I need to go ahead and suck it up, gently loosen them up and back them out and then clean and reinstall by gently screwing them until they bottom out and back out 2 1/8 turns. Does that pretty much sum it up...

[Marcarl]

Thanks for the info and tips, I will be trying the liquid tape trick (I actually have a can at the house), since it will be a little bit before I get the extra cash to purchase the new dia's, But I will be ordering them for sure... The outfit I found the price of $57 is http://metricpartsdirect.com/Default.asp I have ordered from them acouple of times, and so far they have beat everyone else I have found. My local dealer wanted $93 each. Talking about a mark up!!!.

 

Also, just to be clear; the Idle Mix Screws you are reviering to are the factory preset screws, you have to drill out correct? My have been drilled, but I did not touch them out of fear the great cycle gods would come crashing down on me . So if all i read is correct, I need to go ahead and suck it up, gently loosen them up and back them out and then clean and reinstall by gently screwing them until they bottom out and back out 2 1/8 turns. Does that pretty much sum it up...

You've got it just about right, seems it should work because the gods are all asleep this time of year.

Try Flatout MC for a price of $55.53 ea and they a great to deal with.

http://www.flatoutmotorcycles.com/fiche_section_detail.asp

[Condor]

I gotta question. From the simptoms you described my '87 does the same thing. Only runs when the choke is on, and when I try to give it the gas it sputters and stalls out. I can give it short quick busts and slowly build the r's up, but forget having it respond to pure throttle. This is with a second set of carbs. The first set acted this way, so I swapped out the carbs for a second set. When I first installed the second set the bike ran great. MOF awesome!! After a period of time the bike has reverted back to what I had with the first set. I know the diaphrams are good with both sets. I'm thinking I screwed up and didn't check out the fuel tank, and now have plugged up the jets with more crud. Rust maybe?? I did fill up the tank with fresh fuel after the second set success. I can't remember if I added Sea Foam?? Old age thing, too many bikes......

Merry Christmas Y'all..............

[Yammer Dan]

Did you change filter?? When I found the rust in the "bLUE bEAST" I added two filters in line and used Sea-Foam before I ended up changing tanks. Pull loose from pump and check flow into something you can see if any rust is coming thru.

[kycaveman]

Hey Condor, that is exactly what mine is doing!!! Runs up with the choke on, can ease up the REV's with patience, but no sudden moves. I have replaced the fuel lines and the filter, everything coming out looks good, I even drained some and let it set to see what settled. After reading through the other post in this site, I am going to check compression and see how that goes, but I am also going to check valve clearance, It is just a trail and error from now on/.

[Condor]

Hey Condor, that is exactly what mine is doing!!! Runs up with the choke on, can ease up the REV's with patience, but no sudden moves. I have replaced the fuel lines and the filter, everything coming out looks good, I even drained some and let it set to see what settled. After reading through the other post in this site, I am going to check compression and see how that goes, but I am also going to check valve clearance, It is just a trail and error from now on/.

 

I should have added in that last post that the slides are fluttering like they should. I think it's more along the plugged jet line. I'll know later this summer when I have time to get into it further. Right now with 4 Bikes to feed it's a priority thing.....

[wild hair 39]

check the compression,my 86 was doing the same thing,found that 14 0f 16 valves were to tight

[Marcarl]

When you pull the diaphram cover off there is a wee little rubber O-ring at the bottom under the cover. It's easy to loose and if you are missing it, you'll have some trouble.

[Z Factor]

I had similar problems like yours and Condors from having my bike sit for long periods of times. You can read about it in this thread and see the prices I paid.

 

http://www.venturerider.org/forum/showthread.php?t=17638

 

Good Luck

[Condor]

I'd say you did what you needed to do. I this case the bike ran great and started great with the second set, and then gradually got worse over time. That's why I suspect the plugged jets. All the diaphrams in both sets were 100% to the good. If nothing else rears it's ugly head, it's gotta be the jets. Especially since all of them are plugged. I'll post a complete report on my findings when I have time to play with the '87 again. I have a sonic cleaner and will probably dip each carb.

[kycaveman]

Well the bike gremlins must be working on my 85 "Brown Bomber" went out today, started it and it ran pretty damm good, I have not had the chance to do much to it with the holiday but I have put togeather a pretyy good game plan.

 

I wanted to thank everyone for all of there input, I am going to replace the Dia's, the large ones and the small ones, I am pulling out the mixture jets, doing a compressiong test and depending on the results, I will check the valves.

 

 

 

I really do believe the bike is on the right track and will soon be very road worthly... Again thanks to everyone

 

p.s. for those who have asked about the little "o" rings under the Dia' cover, they are all thier and in in good shape.

[CrazyHorse]

I'd say you did what you needed to do. I this case the bike ran great and started great with the second set, and then gradually got worse over time. That's why I suspect the plugged jets. All the diaphrams in both sets were 100% to the good. If nothing else rears it's ugly head, it's gotta be the jets. Especially since all of them are plugged. I'll post a complete report on my findings when I have time to play with the '87 again. I have a sonic cleaner and will probably dip each carb.

 

Condor I had this problem it was my very tiny pilot jets in the idle circuit. No amount of seafoam or soaking helped. I had to poke a steel bristle from a wire brush through them to unplug them. Be careful though. You can look into you gas tank if you take the seat off and pull out the fuel level float. Shine a flashlight in there and see if you have rust mine fortunately was clean as a whistle. Mine would only idle with the choke on. These jets are very tiny and easly plugged even by varnish. I'll bet on this.

[Wags87]

Did anyone mention, you MUST have the air box and lid in place or the bike will blubber above 2000 rpm or so. (4 rebuilds and 2nd set of carbs made me a believer)

[Rocket]

Did anyone mention, you MUST have the air box and lid in place or the bike will blubber above 2000 rpm or so. (4 rebuilds and 2nd set of carbs made me a believer)

 

Yup, in at least a few threads............

[k7mdl]

One think to look for if it feels like fuel starvation at higher RPMs.

 

The braided fuel hose on my bike passed through a very strong wire clip on the top back center of the carbs. It was pinching the fuel line shut enough that it would run the carbs empty at high RPM for some way down the road. When you stop to scratch your head about the situation, and have the key on, the fuel pump is busy refilling the float bowls enough to let the engine run for a while more while you think all is OK again. Until it dies again down the road a few hundred yards.

 

If you are taking the fuel hoses apart at various places to check for clogged lines, proper flow, etc, taking the hose off the carb itself requires you remove it from the clip, which also bypasses the problem, and looks like all is normal. I happened to not put it back in the clip and noticed all was good again, and recalled that was my last and only change. I have seen delaminated hoses that act the same so this was was a very vague possibility that took a while to realize it could happen to me here. Usually an event reserved for coolant hoses.

 

I think the original problem reported in this thread was that the engine speeds up over time, and this is the opposite, but thought I would mention it. Nasty problem to locate.