Strange symptoms...

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Could be. Gonna see if Kyle has a "T" he can bring with him tomorrow along with some 147.5 and 150 mains. I've got a k&n. Does that need to be OEM?

Nope....they work great. One thing that I did was to trim the little bit of a rubber lip that hangs out into the path of the on coming air. DONT trim into the plastic lid. That can let too much air in...and then it wont run that well. Just make certain to use the grease with the filter along to top of the filter to help seal it to the lid.
 
I'm still baffled as to how both this and my '92 ran perfectly for over a decade like this.

What were the floats set like before this happened? When I started messing with my carbs...I ASSUMED that they were set correctly from the factory. When I sent them to Danny.....he said that they were close to 12mm. SUPER RICH.
 
The Dynojet company sets up the stage 7 kits (as per the directions) way rich. I saying that, because I wonder if you were way rich....and now with the floats set right....it has leaned you out thru the midrange....so you need to lean everything else out too?

This is how I learned it. Rich is smooth....but lean is fast.

It could be that I'm wrong.....and there are other issues, but after you eliminate this possible cause, you can look in a different direction.
 
I'm not sure how this seems to come about but I've heard this with about anything that has a Carb. A float bowl is nothing more then a miniature gas tank for the carb. If the floats get to high it will run raw gas into carb throat to low & it can suck air. Moving the float 1 mm one way or the other is not going to make it rich or lean & should not be used that way that's what jets are for.

Dave
 
I have heard that with a higher float level (rich) it is easier to pull fuel from one side of the carb into the throat...and make yourself rich.
+1, our carbs have to have the fuel levels right before jetting is even considered. Too low and you'll starve for fuel regardless of jet size.
 
+1, our carbs have to have the fuel levels right before jetting is even considered. Too low and you'll starve for fuel regardless of jet size.

+1 steve-o
Dorney you have to consider the angle of these float bowls, not like most others.
They sit with the gas in the bottom of the bowls these are sideways so the level is important.
 
Just discovered something... this sputter only seems to happen once I take off after prolonged idle. Perhaps (as Sean stated) fuel is leaking past the float needle a bit.
 
You need to get the bike temp up before doing a quality test.
Hotter plugs (going down in number and colder going higher) will burn off more of your unused gas. Helps if you're rich.
Better for cruising around at lower speeds.

10 mins of your time---https://www.youtube.com/watch?v=zb7WHaL_dz8
 
Ok... It was determined the PO had the floats leaned way out to compensate for a set of huge mains. After Danny set my floats to factory height, the big mains were causing the bike to load up after prolonged idle. The bike still had a high speed bumble which was determined to be lack of carb vent lines resulting in incorrect pressures or something when catching gusts at speed. My final tune is as follows: 147.5 mains, all other jets stock, 1 shim under clip on needles, idle mixture screw at 2.5 on front left (#2) carb with the rest at 3.5, k&n filter in stock airbox WITH "Y" in place, full Holeshot 4-2 exhaust. Bike runs absurdly well.
 
Glad to hear you finally got it all worked out.
Personally that's why after my Stock 2000 put out 119 HP on 2 different Dyno's, I decided I'd leave it basically stock.
I really didn't want to get into all those tuning nightmares I've read about over the years.
I did eventually add Supertrapps and some cosmetic mods but that's pretty much it.
I have been riding it doing just basic maintenance since I bought it in 2001 and it always runs strong.
 
Back
Top