| Author | Message | ||
     Knc52 |
Gearhead- I have never pulled the carb off the bike, and I only loosened the boot when reshimming (I didnt loosen the boot the first time I shimmed, forgot to I guess) but other than that I have never adjusted boot. When I go to take boot off to inspect it, what is supporting the carb? With the airbox off, and me taking te boot off, what holds carb onto bike? EZ- The shims made a big difference in pickup, so I would love to put them back in. I just want to get the bike running good first, then look at getting it better. I'm not a mechanic, and certainly not a professional. There is a chance I messed up the boot, but I don't see how I could. I only loosened the clamps and made sure they were clamped back exactly where they were. I guess me loosening and retightening could have cracked it, who knows. Bad news is, I'm traveling from today through next Friday, so I won't get to work on it until Saturday. I am going to order a new boot tomorrow so it will be there when I get back. Manifold coupler looks good from what I could see, so I don't think I need a replacement there, unless u guys suggest it. Thanks for all the advice... knc52 | ||
| Gearheaderiko |
Dont touch the manifold! Only the fuel line and throttle cables hold the carb to the bike after boot and box are removed. Boot is easy to pinch (open) if the clamps are too tight. If too loose, then air can get past. If the boot is old and it was reclamped, that can crack it. Once you loosen the clamps, you might as well have taken the boot off. FWIW: Maybe its just almost 30 years experience with this style set-up that I dont have any problems. I often try and figure out what could go wrong or remember what somebody has kindly shared here what they did wrong. We all make mistakes. ALL! | ||
| Ezblast |
lol - I resemble that! EZ | ||
| Knc52 |
Hey guys, I'm back from traveling and just picked up a new boot from HD. I will be replacing it tomorrow morning, so I'll let you know how things go... knc52 | ||
| Knc52 |
So I switched out boots, and I'm still having the same problem. When I blip the throttle, the carb backfires. When I got the boot off, I looked it over for any cracks and I couldn't find any. The boot looked fine. I replaced it anyway and will keep the old one for a backup. When I put the new one on, I put the intake side on first and then put the carb side on last. I made sure it was all the way in before clamping it down. When I got the new boot on, I started it up and it idled rough for a minute (rougher than usual) and then gave it throttle and it backfired. I took the airbox cover off while i had it running to see what I could see. The fuel is coming out of the jets like it should and the slide is moving up and down. At this point, I'm out of explanations/ideas. My only thought would be that I don't have the boot on right, and air is leaking in causing backfires. I made sure to get the boot on snug on both ends and clamp it down tight. I don't know what I could have done wrong here. Any chance the backfiring could be caused by something else? | ||
| Gearheaderiko |
Sure, it could be a lot of things, but if i remember, it was the boot and carb you touched last and thats when your problem appeared. So thats where we start. There is a vacuum port on the carb capped by a black rubber nipple, make sure that is intact. We need to back track and ask again how this problem came up. If it came up immediately after the last thing you worked on, thats where we look first. Review that to be sure. Anything else you did to the carb? Changed the plug, set the timing, added fuel. Adjusted the handlers, killed the battery, dropped the bike, etc. Other causes are bad gas, bad ignition module, bad spark plug, bad safety switch, etc. Could go on... As far as tightening the clamp (without torque specs-few have a wrench for it and you dont really need it), you should tighten it just until you see the rubber boot mushroom. Not "oh, it looks like a mushroom!", but you'll just see the rubber start to pop up from behind the clamp (up until this point it shouldnt have moved). I know how tight to go by hand, but that is the only other reference I can think to give that might help. If anybody else has another reference point, it would be welcomed. (Message edited by Gearheaderiko on September 15, 2012) | ||
| Gearheaderiko |
....and you do not have a California edition Blast correct? | ||
| Knc52 |
I don't have a CA bike, so it can't be the charcoal cannister. In my airbox the vent line is plugged, and the plug looks good. I'm going to pull the tank and check my spark plug to see if that's it. The bike ran fine after I installed the plug, so I don't think that's the problem but I want to rule it out. I will take some pictures of my set up to see if you guys can spot anything out of the ordinary. I will get back to you when I check the plug. Knc52 | ||
| Gearheaderiko |
Vacuum port is on the carb, not the air box. It may or may not have the nipple, but it will only have one, and it must be capped. The cap often splits with age. Your PCV line (from the rocker cover) is vented? | ||
| Gearheaderiko |
Definitely make sure the spark plug nipple is screwed on tight and the plug wire fits snug. | ||
| Knc52 |
I live in Southern Indiana, and I bought the bike from a guy who bought it from the original owner. The original owner bought it in Louisville, KY. The airbox has a cap on the vent line, and there was no line going from the carb vent. Therefore I don't believe this is a CA bike (without checking with HD to have them run the VIN.) So I checked the spark plug, and it's fine. Wire is tight and plug was all the way in. I retightened the boot and made sure it was all the way on all around. I tightened the boot until it "mushroomed" and put airbox back on. I saw the carb vent, and it was capped. The cap looked like it was in good shape. After these adjustments, I started the bike and carb still backfired. Logic tells me the problem is the carb, because the problems started when I went to shim the needle. When I shimmed needle, the bike had problems around 65-70 mph. I then took shims out (this is when I loosened the boot for the first time, btw) and then the bike started backfiring. So therefore, logical troubleshooting tells me that the problem is in the carb boot/manifold area or something I did when I went to shim needle. I took the top of the carb off to see if the slide or diaphragm were out of place. When I pulled the top cover and spring out, I noticed a little brass part that I hadn't noticed before. I also noticed the diaphragm was out of the bowl groove. I don't know where the brass part goes (no mention of it in the service manual I have) so I put it in the hole on the top of the plastic thing that sits on the needle. I thought it was the only logical place it could go. I then put the diaphragm back in the groove and put the spring and cover back on. When I started the bike up, it ran for a couple minutes without backfiring at all. Just when I thought we fixed it the carb backfired a couple times. I took some pictures that I would like to show you and EZ if you are willing. Maybe you can see something via the pictures that could help. I tried posting them here but it won't let me because the images are too big. I would like to email them to you if you guys are open to that. knc52 | ||
| Gearheaderiko |
Yes, it would seem carb related then. Coincidences do happen where something will go bad right in the middle of making other changes. But.... Send me some pics! | ||
| Knc52 |
Did you get my email? After 2 days of research, I was going over the CV Notes/Mods page on Nightrider.com. I saw in the Idle Mixture section it mentioned something about the carb backfiring if the idle mixture is off. Come to think of it, I did adjust the Idle Mixture screw after shimming the needle. I remember posting about it because I was shocked that the screw was turned out so far. Could the backfire issue be related to the mixture not being right? With the boot seemingly installed right and all the components of the top section of the carb in place, it seems like that would be the explanation. knc52 | ||
| Gearheaderiko |
Yes. Got your emails but haven't even had time log on a real computer to look at the pictures. Sorry. Adjust the screw to where you found it and see what happens. If you took the screw out, then you're probably missing the o-ring, spring or washer. Gotta go. 'G'night! | ||
| Knc52 |
That's cool, no rush. Hopefully this idle mixture adjustment will cure the problem and it will be a moot point. I have only adjusted the screw once and it was right after I had shimmed the needle. When I started turning the screw back in, it was much farther out than I expected. I turned it in and set for 2 1/4 turns out, which seemed like the best position running wise. Only later did I realize that the bike wasn't properly warmed up when I was adjusting the screw. I made sure the boot was on correctly and tightened appropriately this evening. Tomorrow I'm going to let the bike warm up (carb only backfires when I give it a lot of throttle, runs fine when at idle) and then make adjustment to screw. If my theory is right, I need to set screw to 2 1/2 or 2 3/4 turns for best performance. That should fix the backfiring issue. I'm hoping anyway... I will let you know how it goes tomorrow. knc52 | ||
| Knc52 |
Gearhead, On a side note, I found a reference to someone else who posted a question about the small brass part in the carb top assembly. Nobody really seemed to give a specific answer from what I read... Link: http://www.badweatherbikers.com/buell/messages/201 64/635133.html?1310167956 knc52 | ||
| Gearheaderiko |
Pm sent. | ||
| Britchri10 |
It came from an after market jet kit for the Mikuni. I don't think it is vital but I left it in the carb' as it was there when I opened it up. Following the thread you referenced I got it all assembled and it ran perfectly. The brass part in question sits on top of the needle/shims inside the upper part of the carb. It was still running well when I sold the bike. Chris C | ||
| Axelf |
Does anyone know what size quiet core to get for the Jardine? They have two options - 2" and 2.25" | ||
| Crackhead |
2" QMI2 I installed the Jardine exhaust the other day and it had the hole predrilled in the tip. EZ, Can you add the info to the exhaust info? | ||
| Vicenzajay |
So is the newer Jardine hardware more structurally sound (welds/not cracking/muffler bracket not failing, etc.)? Debating the Jardine and the D&D options as the next system for the bike. I like the idea of a quiet core system with decent power....and I want something other than the V&H that I have at this point. | ||
| Ezblast |
You know the stock hardware for the lower front you are using for the V&H - continue to use it for the Jardine and you'll be fine, their metal mounting hardware leaves too much vibration into the system and that is what has caused issues. Their can is no better than the V&H can and will deteriorate as quickly - so keeping up with the packing is the preventive medicine for that. EZ | ||
| Vicenzajay |
I don't have stock hardware - my current V&H is only attached at the header and the rear mounting bracket. No issues or movement in almost 8K miles that I've had it. It's been on there a LOT longer, though. This is the reason for the questions I have about mounting the Jardine and what I need. All I have on my bike is the two nuts on the stud at the lower front - attached to nothing - as in there is nothing on the lower front of the engine attached to the exhaust system in any way. | ||
| Ezblast |
Your screwed - pictures? EZ | ||
| Vicenzajay |
screwed? Is there no stock hardware available for sale anywhere? I just don't get the screwed comment as the way the system is currently mounted has been working great (for a lot longer than I've owned the bike). My profile pic pretty clearly shows how the V&H system on my bike is mounted. I'm just wanting to get everything together that I'll need to put the Jardine system on the bike. That would seem to be stock lower mounting hardware....I have the nuts and washers on the engine - just nothing rubber. So if someone has part numbers, I'll work this out myself. | ||
| Gearheaderiko |
Sorry Vince, I'm miles from a parts book so I can't help. The D&D is loud but might be a more reliable low maintenance choice and you can mix the v&H/D&D systems (if you want yo experiment). You can make your own hardware. At this point something is better than nothing and I think the D&D comes complete. | ||
| Vicenzajay |
Okay - I might be completely misunderstanding what we're talking about with respect to "hardware". Both the D&D and Jardine systems come with a "bracket" looking steel plate coming off the head pipe for connection to the lower front engine mount, correct? So I'm assuming when we say "stock" hardware, we're talking about the fasteners on the engine? If so, the fasteners are there on my motor, with a washer as well next to the actual mount protusion - just no rubber bushings or grommets there at all. If that's the case, I'll look for rubber bushings to put in between the bracket on both sides and the washers on either side before tightening the nut. Am I way off base here? What am I missing? I'm beginning to be really confused as to what exactly we're talking about. | ||
| Gearheaderiko |
It's sounds right. Do you have the front bracket that bolts to the head pipe (or bolts to a clamp on the headpipe)? By hardware I mean every bracket, bolt and bushing needed to bolt the exhaust up. | ||
| Vicenzajay |
No - I don't have a bracket that bolts to the headpipe at all. Only nuts/washers currently on the motor's front mount protrusion. so am I actually looking for a c-type clamp with a rubber isolating sleeve? That assembly would then go around the head pipe and be bolted up to the front lower mount? I think I'm going to call the dealer....probably an exercise in futility as they're going to be clueless, but at this point I probably don't have much of an option. I would just put rubber grommets between washers on the mounts, but I'm assuming they would just melt given that it's mounted up to the engine. | ||
| Vicenzajay |
I may just wind up going with the D&D. I just don't have a measure in my head for how loud it actually is (it's a straight pipe/can, correct?) My current V&H and wrapped head solution is quite loud - but I think part of that is that the can is pretty much a straight pipe. If there's any baffling in there, it's survived probably more than 10-12 thousand miles at the low side without restuffing - so my current solution is pretty much open/loud. If the D&D isn't much louder than that (or the same'ish), I might just go that route and forget about hardware additions. I would assume - here's a question, that I still would be wise to buy the more robust flange (head flange), a new gasket, two new lock nuts, and the retaining ring - correct? |
