Running like SH*T!!!!!!!!

natek1977 · Posted: May 21, 2007, 4:48 pm Post subject: Running like SH*T!!!!!!!!

If you read lower, you will see I had a post about contact points. Well I got some good advice, and did everything I was told. I cleaned the point faces with alcohol, checked the timing,(it's right on),re gapped, etc. The bike will crank and crank, then finally start. The left side is running strong, maybe too strong. The headpipe gets hot as hell after just a few seconds of running. The right side, however, is blowing a plume of black smoke, barely firing, and backfiring.And the headpipe is barely warm. I should tell you I replaced the plugs, wires, coils, condenser,points, and rejetted my carbs. I am getting a little bit of fuel coming out of the overflow tube on the right side as well. I double checked all wire connections and the wires going into the plugs as well as the ends going into the coils. I am thinking of taking the jets back out and putting the needles back to where they were. Any body think this might have something to do with the running problem? I replaced my pipes with aftermarkets, and put Uni's on. I rejetted from 127.5 to 130, and 45 to 47.5.And I dropped the needles a slot, and reset the floats. I also was wondering if it matters if the wires coming out of the condenser can be reversed or not.They were both the same color and shrink wrapped so I really couldnt tell what wire was what. Should i switch them around? If anybody has any advice, that would be great. These are the last acts of a desperate man. I am thinking about loading it into my truck and taking it to a bike shop. I really dont want to admit defeat, though. So, any input would be helpful at this point. Thanks

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

Headpipe gets hot where? At the head or down the pipe after a few seconds? What pipes are you running? If you have straights you may be lean. I recall running bigger jets with my straights when I had stock carbs. What year is your bike? You have to crank and crank to get it to start. If you got spark then I think you ain't getting fuel. Mind you, the monkeys at the bike shop are lower intelligence than most and are going to do the same things you try to get it to run only then charge you more than the bike is worth. Stay away. Keep trying. Is your battery fully charged? What about after all that electric starting? I feel your pain....sometimes you just need to go have a beer and think about it for a while. Beer is cheaper than shop labor.

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

The right hand side is flooding.

You shouldnt have an fuel escaping at all.

It sounds to me more like that the float in the carb is holed or the arms are bent so the fuel is flooding the carb.

Also a common problem on these engines, that I have personally experienced is failed valve stem seals that let oil mess up the under side of the hot valves and damaged the valve seats.

Sound more like a carb problem to me though. Something still not right with that carb if you ask me.

Xumi · Posted: May 21, 2007, 5:15 pm Post subject: Re: Running like SH*T!!!!!!!!

natek1977 wrote:

:x If you read lower, you will see I had a post about contact points. Well I got some good advice, and did everything I was told. I cleaned the point faces with alcohol, checked the timing,(it's right on),re gapped, etc. The bike will crank and crank, then finally start. The left side is running strong, maybe too strong. The headpipe gets hot as hell after just a few seconds of running. The right side, however, is blowing a plume of black smoke, barely firing, and backfiring.And the headpipe is barely warm. I should tell you I replaced the plugs, wires, coils, condenser,points, and rejetted my carbs. I am getting a little bit of fuel coming out of the overflow tube on the right side as well. I double checked all wire connections and the wires going into the plugs as well as the ends going into the coils. I am thinking of taking the jets back out and putting the needles back to where they were. Any body think this might have something to do with the running problem? I replaced my pipes with aftermarkets, and put Uni's on. I rejetted from 127.5 to 130, and 45 to 47.5.And I dropped the needles a slot, and reset the floats. I also was wondering if it matters if the wires coming out of the condenser can be reversed or not.They were both the same color and shrink wrapped so I really couldnt tell what wire was what. Should i switch them around? If anybody has any advice, that would be great. These are the last acts of a desperate man. I am thinking about loading it into my truck and taking it to a bike shop. I really dont want to admit defeat, though. So, any input would be helpful at this point. Thanks

Sounds like carb problems, not electrical.

Dive back into your carbs and recheck your float levels and float valves - sounds like you're float level is way too high on your right carb, and either an air leak, low float level, plugged fuel filter, or plugged jets on the left.

Check for air leaks at the carb boot on the left cyl, and check for plugged jets there too. Spray a little carb cleaner next to the boot and see if the idle changes. If it does, you have an air leak.

Also - check your fuel filters.

If you are using the cheap uni's, then make sure they aren't blocking the intake ports on the carb (try running without them for a SHORT test)

Pop in a new set of plugs, get it started, let it idle until warm, and pull the plugs. They will tell you a lot about what's going on. Tan = good. Black = rich, white = lean.

If that doesn't work... Take a deeeep breath, and check it all again.

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

I think your solution lies in one of these answers above somewhere. I hate those 20 years late damn troublesome diaphragm pieces of s***. Those M.F.ing things caused me more trouble for the 1st summer I had the bike. I got to the point where I almost kicked my bike over into the dirt and left it. I was FUMING over those cursed things. Pinholes in Diaphragms. Funky junk. Roundslides or flatslides are worth the investment. I threw all those old carbs in the trash so they wouldn't plague anyone ever again. Those are now the first thing I pitch...yes, even before the wiring loom, fugly seat, buckhorns, and other B.S. Sorry for the language...it just brings back ugly memories.

Xumi · Posted: May 21, 2007, 6:14 pm Post subject: Re: Running like SH*T!!!!!!!!

ttmaniac wrote:

I think your solution lies in one of these answers above somewhere. I hate those 20 years late damn troublesome diaphragm pieces of s***. Those M.F.ing things caused me more trouble for the 1st summer I had the bike. I got to the point where I almost kicked my bike over into the dirt and left it. I was FUMING over those cursed things. Pinholes in Diaphragms. Funky junk. Roundslides or flatslides are worth the investment. I threw all those old carbs in the trash so they wouldn't plague anyone ever again. Those are now the first thing I pitch...yes, even before the wiring loom, fugly seat, buckhorns, and other B.S. Sorry for the language...it just brings back ugly memories.

heheheheh - I feel your pain with diaphragm carbs... They are a pain in the ass, that's fer sure. FORTUNATLEY, These carbs are easy to diagnose diaphragm leaks in. Push the piston 80% up into the carb, and put your finger over the top intake port (that leads to the diaphragm chamber), then let the piston slide back down. It should slide smoothly, but VERY slowly ( more than 15 seconds) back into place. If it doesn't.. it's got a leak.

I actually like these carbs. My first street bike had them (an old kz750), and I had a rusty tank... cleaning these carbs was a bi-weekly event for me. I was pleasantly surprised to see them when I pulled them off the bike. It was like saying hello to an old friend... That had been laying at the bottom of the ocean for a few years.

xsjohn · Last edited by xsjohn on May 21, 2007, 7:25 pm; edited 1 time in total

My 80 carbs are great....No two carbs are exactly alike and tune them right and indivually....I now know that once both carbs are set to deliver the exact same fuel to air at all stages at the same time...50 percent of the engine vibrations dissapear...You woud be surprised how much different two carbs are when set identical....Walla......Never would think it was that critical but it is...............With no away around it but to suffer with the vibes............If you think you can do it by ear or plug color you can't......Only get it close.....

www.650rider.com/Forum...=1529.html

John Underwood

Xumi · Posted: May 21, 2007, 7:25 pm Post subject: Re: Running like SH*T!!!!!!!!

xsjohn wrote:

My 80 carbs are great....No two carbs are alike and tune them right and indivually....I now know that once both carbs are set to deliver the exact same fuel to air at all stages at the same time...50 percent of the engine vibrations dissapear...You woud be surprised how much different two carbs are when set identical....Walla......Never would think it was that critical but it is...............With no away around it but to suffer with the vibes............If you think you can do it by ear or plug color you can't......

www.650rider.com/Forum...=1529.html

John Underwood

Hi John,

I was just reading some of your past posts about the laser tuning.. interesting stuff! I've never tried anything like it, so I'll have to give it a shot once I get my XS running and see what happens... Your theory makes a fair amount of sense to me.. I'm mainly a shade tree type though.

I was mainly trying to get him in the right direction of having a running engine. I think fine tuning comes after. <Grin>

xsjohn · Posted: May 21, 2007, 7:29 pm Post subject: Re: Running like SH*T!!!!!!!!

Agreed....But knowing there is a way to take it all the way helps...Just get it running first by the book and do the best by ear and plug color and then proceed to really tune it in..... Have to ride it a while to determine where to start....Write it down left and right carb and after a while you will see which way to go if any....Plugs precelin should not be stone white or to darkened is a good place to start after 50 miles or so...

.....If you have a real cleaning problem..........There is a cab cleaner called Dragons Breath made by Castle and is sold at auto zone...This stuff is really the strongest cleaner I have ever experienced and will burn you skin, eyes and the glasses right off your face....Put a fan behind you and be real careful....Don't breathe it....Neutralize with brake cleaner spray and get some gas in them.....Carbs can be a butt ho especially with junk in them from sitting...Once you get that crap out you will be happy happy.....

John Underwood

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

Hey John....how much did you pay for that laser deal? I've done pretty damn good with my ears but it is interesting. You seem to really have gotten your moneys worth from it. Any links?

xsjohn · Posted: May 21, 2007, 9:15 pm Post subject: Re: Running like SH*T!!!!!!!!

No kidding.....Harbor freight 20 bucks....The bigger one......May be off sale now 30 bucks.......Would like to have a 50 dollar one....but... Its amazing what you can do with it.......No guessing.......Hard to determine heat from just looking at the plug color...Could be 20 degrees different and not show up on the plug......Been measuring right on the plug metal below the porcelin for the best readings after the bike sets for 30 seconds or so and the plug becomes the same heat as the head.....Got mine within 3-5 degrees and does make a different in everything....Once you find how much each carb is off then you can move the needles up or down even if they are different say 10 thou....

Bunch of good lazer thermometers out there not to expensive.....

John

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

Harbor freight? Ain't that like Northern Tool and Equipment?

xsjohn · Posted: May 21, 2007, 9:24 pm Post subject: Re: Running like SH*T!!!!!!!!

Similar....chinese stuff cheap......Ebay too....laser thermometer...

john

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

I gotta admit, I do actually like these carbs.

Obviously the diaphagm is the weak part, but they do flow and work well.

y friend had a big bore chop we put VM's on it, and the difference wasnt great on top end. I think if you get the originals well and work on it, they would be OK. The flow of course is interupted by the butterfly, not ideal but not total crap.

Unless your diagragms are knackered. Sheet how do you spell diagrapgc?

blast.

Good tip on test as well.

xsjohn · Posted: May 22, 2007, 9:40 am Post subject: Re: Running like SH*T!!!!!!!!

Speaking of diaphragms.....I have seen them new and seperate from the slide somewhere for not to much.....Has anyone replaced the diaphragms on their slides and if so how is it done...Mine are still ok but it is inevitable...39000......Thanks

John Underwood

Xumi · Posted: May 22, 2007, 1:06 pm Post subject: Re: Running like SH*T!!!!!!!!

xsjohn wrote:

Speaking of diaphragms.....I have seen them new and seperate from the slide somewhere for not to much.....Has anyone replaced the diaphragms on their slides and if so how is it done...Mine are still ok but it is inevitable...39000......Thanks

John Underwood

John,

When the Diaphragm on my vulcan went TU last year, I researched replacing/repairing quite a bit.. this is what I learned.

Yes, you can buy a separate diaphragm and mount it. You need a press and some other goodies that I don't have. I'll look for the link and get back to you for the instructions.

You can get by for a while with repairing your diaphragm.. I used rubber cement and clear packing tape (the really cheap thin kind is very flexible) - just cut it in as small a strip as you can get away with to plug the tear or pinhole, then give it two thin coats of rubber cement on each side (after cleaning with alcohol of course), letting it dry 1 hour between each coat. I ran for about 3000 miles on mine before I got rich enough to replace it (damn Kawasaki parts are friggin expensive!) without problems. I've even heard of people using a band-aid to patch a torn diaphragm in an emergency. I can take pictures of my repair and send it if you want.

There is also a company in the UK that will put a new diaphragm on a slide for you.. They claim to have superior diaphragm and recondition the slide and a bunch of other BS - I didn't try them as shipping + the price was about the same prices as a new slide, and they take a few weeks. I'll try to find that link too.

Brett

Xumi · Posted: May 22, 2007, 1:32 pm Post subject: Re: Running like SH*T!!!!!!!!

xsjohn wrote:

Speaking of diaphragms.....I have seen them new and seperate from the slide somewhere for not to much.....Has anyone replaced the diaphragms on their slides and if so how is it done...Mine are still ok but it is inevitable...39000......Thanks

John Underwood

A shop in the UK that will put on new diaphragm...
www.nrp-carbs.co.uk/ya...hragms.htm

A shop in the US that will put on new diaphragm.. not cheap, 3 weeks turn time.
www.motorcyclecarbs.co...ir_W35.cfm

Another way to repair diaphragm.. never tried this method.
www.xs11.com/forum/sho...2#post2972

Darn it - I can't find the instructions link for how to replace the diaphragm... Will see if I have the link at home tonight.

xsjohn · Posted: May 22, 2007, 4:03 pm Post subject: Re: Running like SH*T!!!!!!!!

Xumi.....Dang.....We really have to learn to do this ourselves.....Can't be rocket science...but have said that before......

Finall got both plugs burning at 226 degrees highway 85 degrees today. Each carb took totally different tuning...not to bad after I convinced myself that this was really happening...One side the needle had to be raised .010 higher than the other the air screw 1/4 farther out and the main jet one size bigger than the other. Go figure a friday carb and a monday carb..Now both are exactly the same and it sure runs along smooth...Have another set but that woud be another story for sure....Don't like to tune new carbs in the summer for obvious reasons.....

Thanks for the help

John Underwood

Xumi · Posted: May 22, 2007, 4:47 pm Post subject: Re: Running like SH*T!!!!!!!!

xsjohn wrote:

Xumi.....Dang.....We really have to learn to do this ourselves.....Can't be rocket science...but have said that before......

Finall got both plugs burning at 226 degrees highway 85 degrees today. Each carb took totally different tuning...not to bad after I convinced myself that this was really happening...One side the needle had to be raised .010 higher than the other the air screw 1/4 farther out and the main jet one size bigger than the other. Go figure a friday carb and a monday carb..Now both are exactly the same and it sure runs along smooth...Have another set but that woud be another story for sure....Don't like to tune new carbs in the summer for obvious reasons.....

Thanks for the help

John Underwood

True - it isn't rocket science.. just motorcycle science, right? Very Happy

I think the most difficult part would be removing the old diaphragm without destroying the ring, or finding a way to fabricate a new one.. after that a press and a little inspiration for a fixture should put it back together.

How often do you end up adjusting that fine tuning? Is it very temp sensitive to the ambient temp?

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

I usually tweaked my 36 mikuni powered stock xs every time the temps changed. A bit different temp and humidity. Being stock it would've worked fine had I left it but I hear and feel its attitude on the road and adjust carbs accordingly. A little more air, a little less air. Get the idle just right.

On high compression motors be prepared to carry a flathead screwdriver with you at all times (i would anyway). If you are a bit out of tune and blow a carb off the boot (common on these bikes) it's gonna be tough to get back on. Also, it's more temperature sensitive. Especially hot startups, which is why I'm trying out Johns cooler idea for my bore kit. Can require on the fly adjustments (of course not while your riding) to maintain proper tune from hot daytime to cooler night. However, the high compression motor can still be a one kick machine.

xsjohn · Posted: May 22, 2007, 5:10 pm Post subject: Re: Running like SH*T!!!!!!!!

I can actually run a tad leaner that before in the summer with the cooler so that will work out better in the winter with the cooler covered completely....Used to have to run awful rich for the long hauls in the summer --not anymore.......

John Underwood

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