| Author | Message | ||
     Titusand |
All I want is my now non-stock Blast to perform like it did when stock! I am thinking about selling this one and finding a low milage creampuff and making sure I keep it stock. Grr! | ||
| Ezblast |
Too tarded - lol EZ | ||
| Gearheaderiko |
Obviously something is amiss! It will cost you less to put this one back to stock and a used bike is another gamble. What would help is a step by step accounting of what you have done to your Blast. | ||
| Titusand |
1- Stock exhaust pipe failed, replaced with Jardine, rejetted to 45/175. 2- K&N filter 3-tranny issue, required the case to be opened. Performed by Harley-Buell dealer that still likes and welcomes Buell customers (unlike another place that I boycot) 4-Mechanic said after reassembly, it was running lean, he suggested putting carb pump from 883 in it, and he did so. (He also mentioned that if it's using too much gas to contact him, but naturally I'm on the road now on vacation so no chance to discuss it with him yet.) 5- Current performance: a- runs perfectly under 70-75, b- seems to misfire above 75, top speed formerly 96 now 85 only, c- used a lot of gas on this highway trip (35mpg) (no info on in-town gas use yet), d- when warm it starts harder than before, e- popping sound when letting off gas at high RPM My guess is this: too rich below 70 but then leans out… ? Maybe? Not sure. (Message edited by titusand on August 07, 2014) | ||
| Titusand |
From my previous post: I took the P3 on a longish ride yesterday. Tank was filled with 91 octane. It was running fine, passed a couple of trucks and hit 92 no problem. I was running about 75-78 mph but got 37 mpg only. I put in 93 octane and shortly thereafter it started missing a little at high speed and wouldn't go above 84mph. I was traveling about 75-78mph It stalled at 58 miles because I needed the reserve already! Any clues? THANKS. | ||
| Titusand |
I just did a run to check on it: the engine make 2 quick "braps" after twisting the throttle before the power comes on. When letting off the the throttle in responds normally. I also filled up, 43 mpg, time before 30 mpg, then before that 37 mpg. | ||
| Gearheaderiko |
He recommended an 883 carb? WTF? Good dealer, clueless mechanic. Before you go any further you need to put the Blast carb back on or (I'm assuming you now have a manual 'choke') set the 883 carb to Blast specs. The 883 carb has no provision for a TPS, therefore you do not have a mechanism to change the ignition timing and advance curve from part throttle to wide open throttle (WOT). This alone will kill mpg. If you don't remedy this, your mpg will always suffer. | ||
| Gearheaderiko |
You must also disconnect the accelerator pump ASAP. This is costing you mpg and causing poor running. | ||
| Gearheaderiko |
That carb is your demon. | ||
| Gearheaderiko |
Okay, put the carb back to Blast specs. I misread and thought he put an 883 carb on. He's still clueless. Disconnect the accelerator pump. ASAP. ••••!  | ||
| Titusand |
OK, I am searching the forum, and I have car experience… but in case I don't find the answer, how is the accelerator pump disconnected? (Message edited by titusand on August 08, 2014) | ||
| Buellistic |
Check the TIMING !!! | ||
| Gearheaderiko |
Since the Blast didn't come with one, you won't find instructions. I'll see if I can get a picture. | ||
| Titusand |
THANK YOU! I am thinking this is not a timing issue because it runs great below 70 or so, it's the lack of power at the top end, and the fact to get to run steady at 75 I really have to have the throttle way back, and at say 80 the motor is somewhat acting like its hitting the rev limiter. I've been shopping bikes online, but in large part that has just convinced me how much I like the engineering choices made in the Blast, so I'm determined to get this bike to run perfectly. (Message edited by titusand on August 09, 2014) | ||
| Gearheaderiko |
In the center of the picture, on the bottom of the carb, is a 1" triangle shape with 3 screws holding on a cover, with a tube going up from it-that is the accelerator pump. On top of that tube should be a tiny rubber boot with rod linkage coming out. That linkage is attached to another piece which attaches to the throttle cables. These pictures show the rod and boot removed. The second pictures shows all linkage removed. The first picture still has part of the linkage (the black plastic piece). The main goal is to remove the rod that goes into the pump-it just pulls right out. The second goal is to remove the remaining linkage as some if it when left loose can hang up your throttle. As evidenced by the first picture, some linkage can be left on, but it's risky. The pump remains in place. Besides pulling the rod out, there is nothing else to do to it. The Blast can't handle an accelerator pump and a lot of tuning goes into trying make it work with that pump attached. Unless you have a specific application for it (some form of 'racing') it just hinders performance. It will cause the hesitation you described and use up a lot of gas!   | ||
| Gearheaderiko |
Sorry I don't have a picture with all the linkage attached, but you have it on your bike already (unless he used some funky set-up). After it's de-linked, you'll have to see how it runs. 45/170 (or 45/175) jetting should be darn close to perfect. I'm hoping no other changes were made to your carb. Let's see how it runs. Regrettably, you may have to check your timing as we don't know really what else they did to get it to run right and didn't tell you. Not a big deal. But let's take one step at a time. | ||
| Titusand |
WOW! I owe you a pizza. | ||
| Gearheaderiko |
Thanks, but Let's get your bike fixed first!! | ||
| Gearheaderiko |
PS you might be able to just remove the rod only. I'm thinking no, but it might be possible if nothing else is hanging. Not all set-ups are exactly the same and yours might be "different". Use caution and check carefully. | ||
| Buellistic |
Loose a hundred pounds !!! | ||
| Titusand |
lol, if I lost 100lbs I'd be back at the weight I was about 5th grade, lol | ||
| Titusand |
there is a complete linkage right on that place. it will be very easy to remove. | ||
| Titusand |
 | ||
| Titusand |
So as I understand now, the black plastic part is lowered by the carb linkage, and this presses the accelerator pump. At idle I gave the throttle of a few turns and watched it. As I stated above, the engine gives 2 "braps" before the power comes on, and this was accompanied by two black puffs of exhaust. I rode it as-is for 200 miles today. The gas mileage remained in the 30's on the expressway, though I got 57 mpg on a two land road doing 60mph. The lack of power resolved itself. I believe this was caused by gas I bought. After running another 2 tanks through, no more issues at high speed other than the above described hesitation. | ||
| Gearheaderiko |
The pump causes the hesitation. Consistent speeds will yield better mpg as you are not dumping the extra gas in the engine that it doesn't need. Disconnect it and I guarantee the hesitation will go away. FWIW: pull off the air box and watch the carb intake as you pump the throttle. You'll see it squirt gas directly into the carb intake. Normal Blasts don't get that and that is what's causing those puffs of black smoke and poor mpg. | ||
| Gearheaderiko |
PS yes, you've got the accelerator pump deciphered and how easy it will be to disconnect it. | ||
| Gearheaderiko |
It is a stock Blast carb and they didn't actually switch out the whole carb, right? I just want to be sure we don't have more mpg issues and that's the cause. | ||
| Titusand |
Same, original carb! | ||
| Titusand |
I disconnected the link and you were %100 right , no more hesitation. I took it around the block and it was very good. | ||
| Gearheaderiko |
  | ||
| Titusand |
I just did a run on I-75 and the in-town portion there and back. 45 mpg including one long, hard pass I made. It does not hesitate and it runs very smoothly. Top end power is good although not better than stock. The MPG is still on the low side, but disconnecting that pump has been a big improvement and a good accomplishment for today. I'm going to continue making MPG notes. There's one other issue, a somewhat hard start when hot after sitting for a minute or two, occurs frequently when stopping to fill-up. ANYWAY, THANKS A TON. | ||
| Ezblast |
45 to 50 - with those mods should be right. EZ | ||
| Titusand |
I am reviving this old thread. I'm using the Blast a lot this year. At 60 MPH it gets 50-55 mpg. At 75-80 mph it goes down to 34 mpg, that gets me 48 minutes of expressway riding before I hit reserve. It starts and runs like a champ up to 70mph. At 75-85 it has some hesitation and high fuel usage. Boot replaced at 5,000 miles out of caution. It has hit 96 mph this year, but it's ability to do that comes and goes. I'm stumped. Prior carb mod, with fuel accelerator is disconnected. Other mods: 1- Stock exhaust replaced with Jardine, rejetted to 45/175. 2- K&N filter, 3- After market shift drum. Otherwise stock. I'm still with this gas hog issue at expressway speeds. Any ideas? | ||
| Gearheaderiko |
If you using a non Blast carb, how are you adjusting the partial throttle spark advance and WOT spark advance? If you simply have the TPS disconnected, that can affect mpg, but you won't really notice a difference in power. Have you checked the timing cup to see if it's loose? That can cause your symptoms. Also, if you're using a non Blast carb, you MUST use the Blast vacuum piston spring. |
