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Posted

Does the carbs on a 1990 Virago 1100 have accelerator pumps? Reason I was asking is because I went to look at one last night and before the guy cranked it up, he rolled the throttle wide open several times before he tried to crank it. It cranked right up as soon as he hit the starter switch but it seems useless to roll the throttle open if it doesn't have pumps.

It seemed to run out well and I bought it for a Christmas present for the wife....haven't gotten it home yet...trying to surprise the wife Christmas day

Posted

Sweet bike. Bet your wife will love it. Several of us here own the 1100 Virago.

 

Now, to answer your question... No. There is no accelerator pump incorporated into the carbs.

 

Sometimes old habits are hard to break....

 

I have two friends here that are looking to by 1100 Viragos right now if anyone knows of any for sale at a decent price.

Posted

There is no mechanical accelerator pump as such. The accelerator pump "action" is built into the venturi design somehow, where a quick snap of the throttle will give an extra shot of fuel. I don't fully understand it. But rolling the throttle grip several times before cranking it is doing nothing more than flapping the throttle plates.

 

A fantastic Christmas present. She ought to be thrilled.

Posted
There is no mechanical accelerator pump as such. The accelerator pump "action" is built into the venturi design somehow, where a quick snap of the throttle will give an extra shot of fuel. I don't fully understand it. But rolling the throttle grip several times before cranking it is doing nothing more than flapping the throttle plates.

 

 

Yup, I bet it was ignorance.

 

Here's what I read some time about accel pumps. I used to think that an engine needed an extra shot of fuel upon application of throttle, but that's not actually true. It needs the same air/fuel mix that it always needs. What happens in the design of most automotive carbs is that there is a brief moment where extra air is admitted into the engine without enough fuel. The accel pump is a band-aid to cover the hole. CV carbs are sensitive enough to throttle opening that they do not have this "hole". At least that's how I understand it.

 

Jeremy

Posted

I'm sure the wife is going to go banannas Christmas morning. I think I am gong to wrap the key in a small box and put it in her stocking. She'll be looking for something big under the tree and there won't be anything. She'll probably start wondering what the #$^@ is going on.

This Virago has after market pipes and it really does sound sweet. Hate to admit it but it does sound better than the RSV!!

Posted
Yup, I bet it was ignorance.

 

Here's what I read some time about accel pumps. I used to think that an engine needed an extra shot of fuel upon application of throttle, but that's not actually true. It needs the same air/fuel mix that it always needs. What happens in the design of most automotive carbs is that there is a brief moment where extra air is admitted into the engine without enough fuel. The accel pump is a band-aid to cover the hole. CV carbs are sensitive enough to throttle opening that they do not have this "hole". At least that's how I understand it.

 

Jeremy

 

You know, I'll bet it's the one carb per cylinder setup that makes them that sensitive. The intakes ducts are short, the throttle plate is basically right in the intake port, and the plenum is virtually nonexistent. When the throttle plate is opened, there's no other place for the cylinder to draw air and fuel from but the venturi. By contrast, in an older car with a V8, single carb and dual plane manifold, the plenum is huge, the runners are long and have a convoluted shape, and each cylinder can draw not only from the carb, but steal from three other intake ports as well. The vacuum signal from a given cylinder is well damped and long lost by the time it gets to the carb. Thus the hole, and why automotive carbs need a mechanical accelerator pump to go over rich for a second to cover it up.

Posted

 

I have two friends here that are looking to by 1100 Viragos right now if anyone knows of any for sale at a decent price.

 

I was looking for a nice one last spring. I did find one that looked nice in pics on ebay at a Harley dealer. It went for $2700. I was afraid to buy sight unseen though. Locally the ones I looked at were not good. A guy claimed his 98 was in great shape, but it had a head gasket oil leak and was not pristine.

 

In 2002 I bought my wife a like new 95 for $3000. I couldn't find one that nice this time around.

Posted
If you want to unleash the beast that is inside the Virago, send me an email.

rod-virago@cox.net

I am happy to help. Rod

 

Want to add a little to this comment ? :think:

 

My wife has a 97, 1100 Virago that she has been riding for about 3 years now. She rode it to Vogel and to the Colorado International meet via the Blackhills and Yellowstone.

 

Nice bike, and fun to ride.

 

Brad

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