velocity stack with choke for walbro 990

[kbreaux100]

i just found a velocity stack that comes with a choke that is built in. this looks great being ive got a walbro 990, which has not choke, and i live in colorado which can be a pain when starting cold. my question is, has anyone tried these? are they worth it? also, i noticed the one i see comes with no hardware. wouldnt i need longer hardware to install a stack? how long?

 

[rampagemt]

They indeed have been tried and stay away from them as the choke will allow dirt to get past and will damage your motor

 

[Deluge]

They indeed have been tried and stay away from them as the choke will allow dirt to get past and will damage your motor

+1

They're vulnerable to dirt.

 

[rampagemt]

If you have problems with your 990 in the cold just put a plastic sandwich bag over air filter with a rubber band and it will pop in no time

 

[kbreaux100]

gotcha. yeh i saw it on ebay, but when i looked em up on ddm, it said only for onroad use. oh well, guess ill have sandwich bag and rubber band in hand till it warms up. sucks its freakin april and were still having blizzard warnings! but if i do get a regular velocity stack, do i need longer hardware? im assuming so but alot of the kits look as though they don't come with the hardware. i found that kinda wierd. guess these companies like to cut costs anyway they can

 

[vpalace]

I got my stack from TGN. Came with an o ring and I used the stock hardware. Bolted up fine.

 

[Guest]

If you have problems with your 990 in the cold just put a plastic sandwich bag over air filter with a rubber band and it will pop in no time

That's what I do. Works great.

 

[kbreaux100]

ok so i got the dt1 dual stage air filter with a 1 inch velocity stack. hope they work well together. will my stock hardware work for these or do i need longer bolts?

 

[rcgasser]

Your stock hardware will work fine.

 

[rcgasser]

I would like to add that the 1in velocity stack has a larger opening then the 3/4 stack to allow for a choke and since you are running the 990 you will have no choke. So hopefully someone else will chime in will this still line up ok? I have just always used the 3/4 stack with the 990 carb.

 

[Deluge]

Yeah, it'll line up fine.

 

[Guest]

I would like to add that the 1in velocity stack has a larger opening then the 3/4 stack to allow for a choke and since you are running the 990 you will have no choke. So hopefully someone else will chime in will this still line up ok? I have just always used the 3/4 stack with the 990 carb.

The 1 inch is preferable. I have a 3/4 inch and never used it. The opening in the 3/4" stack is smaller than the carbs.

 

[Chief409]

I" on a 990 bolts right on. With the DT1 it's the same as my setup on the DR. I also have a thick gasket between the stack and the carb, so the bolts are a bit, 3mm, longer then stock. Without doing dyno runs I have no idea if it helps the power, but, who cares. I like it. And the DT1 has a firm, no leak mount.

Stay away from prefilters with the DT1 unless they have a drawstring. The ones with elastic will destroy the filter, it will become separated at the joint between the filter and ring. DT1's don't need prefilters anyway. I use FAB1 spray on filter oil and DT1 Super Seal filter cleaner. I have a clear container I use to clean the filter, then let the dirt settle out and pour the clean filter fluid back into the can. Both are available at motorcycle shops. Another good filter oil for DT1 filters is FFT. I like FAB1 in the extremely dusty conditions here.

 

[alfred e numan]

I have ran both v-stacks on assorted engines -carbs. For me- the tall v-stack produces more high reving power- dt1 two stage-990. I know- i know- big horse power engines are a rush to drive- have a few of these.- My favorite combo on the xb for just screwing around? The Cy 29 two bolt with ada short- 3/4" v-stack- wt 813 with a cut butterfly valve- jetpro rear mount.- This set up seems almost electric- lienar- no hit- decent top end rev. I really have to wonder if fuel flows faster tru a 2 bolt- stronger fuel signal at less than screaming rpm-s. This could? explain why this 29 set up pulls soo hard-- 7,500 to around 12-13 gran more or less. It a kick as little engine in super loose dry conditions.

 

[alfred e numan]

not trying to twist this thread around- just wanna add- this 29 has a Hy bottom end- 30mm crank- nachi bearings-zen seals. There is zero crank side to side movement on this engine- this lack of slop could very well be a factor in the way it pulls @ lower revs?

 

[rcgasser]

The 1 inch is preferable. I have a 3/4 inch and never used it. The opening in the 3/4" stack is smaller than the carbs.

Ok thanks.

 

[kbreaux100]

a. e. numan, i know your giving some excellent info here, im just not literate enough about these engines to understand!! Really wish i was cuz theres alot of info there. as to the other posts, im glad to hear i picked up what seams to be a good combo. thanks for all the helpful feedback guys.

 

[Chief409]

Don't have enough experience with every thing. less then a year with large scale. But, from my experience, it'll work. In racing, any edge is a advantage. Like they say, love your competitors', someone has to be second.

I'm not that clever on engine builds, so my engines (and new custom 5b) are from O'Neil Brothers Racing (OBR).

Dunetoberfest isn't that far away. Who else besides me is running a Red Cat? Rob?

And My Dune Runner is Kick Ass! It'll be at the Glen Helen sand drags the 27th. Think you'll beat me? Only one way to find out, SHOW UP!

Chief409

 

[kbreaux100]

Ok I got my velocity stack today and tried to put it on but the hardware is not long enough!! Am I doing something wrong because I thought someone said I could use the same hardware. I put gasket, Carb,gasket, 1" velocity stack, and then the bolts wont go through to threads. What hardware do I need? I don't want to get too long of screws and mess things up.

 

[vpalace]

Mine screwed on fine.