setexascustoms
Member
Hi everyone, I'm new to the forum and to the Vmax. I picked up my '85 with about 18k mile on it. It had very poor idle quality, bogged in between shifts and bucked and popped at cruise. I did the shotgun and it made a huge difference, but there are still some issues.
The idle is erratic, sometimes it idles high and fairly smooth and sometimes it idles low and rough and wants to die. It also still pops at cruise, whether it be at 3000 RPM in town or 4500 on the freeway, and pops VERY loud on deceleration with light throttle. These problems seem to come and go (or at least get better or worse) like the idle quality.
It does have a vacuum leak around the throttle shaft on the right rear carb. Does anyone know where I can get the shaft seal and how hard it is to change? Also the air box boots, where it attaches to the carbs, are deformed and it's near impossible to get the air box to sit all the way down and seal on all four carbs. I see the air boxes are pretty cheap on ebay, so I may pick up one in better shape. The fuel tank looks pretty good, best I can tell, but there is a little sediment at the bottom. I looked down the neck with a flashlight and a mirror as best I could, and didn't see any rust. The fuel filter is clear and looks good. I did get just a tiny bit of trash when I drained the bowls doing the shotgun, just enough to see. Is this typical, or should there be none?
This bike also has the Cobra 4 into 4 slip ons. I understand that they actually lose power. If I'm going to have to pull the carbs to change the seal I might as well check the jets and change them if need be. Any recommendations for a stock bike with this exhaust at sea level? I do plan on changing the pipes later, but for now I'm on a tight budget and would like to get it running as well as possible with this set up.
Any question that might help with diagnostics, just fire away. Thanks for the help, guys. This place has already proven to be a wealth of information.
The idle is erratic, sometimes it idles high and fairly smooth and sometimes it idles low and rough and wants to die. It also still pops at cruise, whether it be at 3000 RPM in town or 4500 on the freeway, and pops VERY loud on deceleration with light throttle. These problems seem to come and go (or at least get better or worse) like the idle quality.
It does have a vacuum leak around the throttle shaft on the right rear carb. Does anyone know where I can get the shaft seal and how hard it is to change? Also the air box boots, where it attaches to the carbs, are deformed and it's near impossible to get the air box to sit all the way down and seal on all four carbs. I see the air boxes are pretty cheap on ebay, so I may pick up one in better shape. The fuel tank looks pretty good, best I can tell, but there is a little sediment at the bottom. I looked down the neck with a flashlight and a mirror as best I could, and didn't see any rust. The fuel filter is clear and looks good. I did get just a tiny bit of trash when I drained the bowls doing the shotgun, just enough to see. Is this typical, or should there be none?
This bike also has the Cobra 4 into 4 slip ons. I understand that they actually lose power. If I'm going to have to pull the carbs to change the seal I might as well check the jets and change them if need be. Any recommendations for a stock bike with this exhaust at sea level? I do plan on changing the pipes later, but for now I'm on a tight budget and would like to get it running as well as possible with this set up.
Any question that might help with diagnostics, just fire away. Thanks for the help, guys. This place has already proven to be a wealth of information.
