| Author | Message | ||
     Invader_zim |
2007 Buell Blast, approx 8,000 miles. Ok so I bought this bike used and about a week later I've been having this issue since. I'll be going down the street and go to accelerate and it will hesitate. It jerks and bucks slightly unless I ease off the throttle. It only happens somewhere in the middle of the rpm range (5th gear between approx 60-70, 4th approx 50-60ish. 3rd 40-50ish, second 30-40ish. It's less noticeable in firs if at all). So far I have replaced the carb boot, spark plug, plug wire. I've pulled and cleaned the carburetor (it has 170/45 jets. Not sure if those are the stock jets or not). It came with a k&n filter which is why I decided to check the jetting on the carb. I have also tried adjusting the fuel mixture screw and it still has this issue. Any help in shooting this issue out is appreciated. (Message edited by invader_zim on March 02, 2017) (Message edited by invader_zim on March 02, 2017) | ||
| Invader_zim |
Also the spark plug is dark, so it's running rich. | ||
| Gearheaderiko |
So it's always done this since you got it? Did the previous owner also have this problem (that he mentioned)? | ||
| Invader_zim |
No, it rode fine for a while after I got it then it started doing this. | ||
| Gearheaderiko |
Is the vacuum nipple on the carb plugged? Cap not cracked? Is the bike stock? Did you do anything (really-anything) to your bike before the started? Picture? Everything you did to the bike was done after you had a problem? It's not a California model, right? Have you tried cracking the gas cap and seeing if the problem goes away? Have you overfilled the oil? (It only takes 1.5 quarts-2 quarts max). | ||
| Invader_zim |
I did the boot from the carb to the intake first as the boot was cracked and I originally thought that was the issue. After that I replaced the spark plug (ngk iridium), plug wire, oil change with mobile 1 v-twin 20w-50 with a k&n filter. I've pulled the carburetor and cleaned the fuel bowl, jets, needle, ratio screw and every port that I could find via multiple carb cleaning guides.(the problem started right before I did the boot and has persisted) also I have sprayed carb cleaner around the boot, manifold and vacuum cap to see if the was a change in idle(I couldn't tell any change) | ||
| Gearheaderiko |
But the vacuum nipple on the carb is plugged with a good cap? How many quarts of oil? Plug gap? Is the nipple still attached to the plug? Is the plug cable secure on the plug? cleaning the carb is rarely ever necessary on the Blast and often just leads to more problems. If someone tells you to clean the carb it literally means "I have no idea what the problem is, but I hope that helps". It rarely helps. | ||
| Invader_zim |
The vacuum nipple looked good when I had it off yesterday, I may get another since they're cheap enough just to have peace of mind. I used almost the two quarts of oil, I made sure the bike was well warned up before checking the oil level. It's an NGK iridium plug. Please tell me if I'm wrong but I thought you didn't need to gap them as the conductor tip was fragile. As for the carb, it looked a bit dingy and I wanted to make sure the gas in the bowl hadn't turned to varnish as the guy I bought the bike from had about 10 different bikes and this probably didn't get ridden often. | ||
| Invader_zim |
Also I'm pretty sure it isn't a California bike. I'm in Florida. | ||
| Gearheaderiko |
CA bike-have to ask-people move and it would be an easy fix! Iridiums don't need to be gapped, but should always be checked. One good drop and they're done for. Almost 2 quarts is still safe, but probably overfull a few ounces. Vacuum plug probably okay, some don't even know they are there and they crack over time. Try cracking the gas cap and run through the midrange. Be careful not to dowse yourself with gas. Shim the carb needle with 2 #4 washers. It shouldn't really be a fix to a problem, but it might be a fix to a problem you don't really have. It is stock, right? No mods whatsoever? At 8000 miles it's barely broken in and should need nothing. Except maybe rubber that has deteriorated with time. DONT BUY DUNLOP TIRES FOR YOUR BLAST. | ||
| Invader_zim |
How do I tell if it's a Cali bike? When you say crack the gas cap, do you mean just the pull tab, or pull the whole cap off? When I went through the carb I noticed the needle had three washers already in it. I pulled one out so it currently has 2. I don't know exactly what is stock (I know the k&n filter and the previously mentioned washers on the needle aren't stock) | ||
| Invader_zim |
And yes, I've heard about the Dunlop ties being crap. I'm planning on some Pirelli tires | ||
| Gearheaderiko |
CA bikes have a soda can sized black canister mounted under the seat above the rear tire. It also says CA on the VIN decal and swingarm decal. Crack the gas cap enough so it's vented. So the carb has been molested, I wonder how much and did the previous owner foul it up. Are the washers fit correctly-do they hang the needle up? What happens if you remove them all? They must be #4 washers otherwise it will cause problems. Is the idle mixture screw 2 1/2 turns out? At this point it's still difficult to say where the problem lies because at 8000 miles on a 2007, most problems are owner/maintenance created. So sorry if I ask a lot of questions because history has proven that many problems on low mileage bikes are owner created, especially if it's no longer stock. A few pictures would really help. | ||
| Invader_zim |
Well I ended up figuring it out. My exhaust cracked and split open right where the pipe meets the muffler (damn potholes) and the issue of hesitation went away. Got the muffler and pipe welded back together and the issue returned. I did the stock exhaust mod and it's running good again. |
