K&N replacement filter for 79 850G

[Guest]

A friend of mine is tuning up his 850G. He replaced the stock filter with a K&N http://www.knfilters.com/search/prod...x?Prod=SU-1200
He now reports that it runs funny above about 5000 rpm. It sounds to me like he needs to go up a size on his main jets. Would anyone else offer advice?

[marvinsc]

Have Him Double Check that His Airbox is Sealed. Most 850 Owners Have to Go Through the Rite of Passage of Fabbing Filter Box Gaskets out of Weatherstripping or Tubing. The Seal is Critical for the Carbs to Function Normally. I doubt the Filter Itself is the Problem.

[koolaid_kid]

He said he fabbed a gasket, and also siliconed it. I was surprised that it did not fit better.
I'll have him double check his work. Thanks.

[mark]

My understanding is that the K&N's shouldn't affect the carbs at all.

What do you mean by "runs funny"?

[rustybronco]

My 82 gs850 though it has different carbs than yours has a k&n in it and NO problems all the way up to the top.

[koolaid_kid]

By runs funny (his description) he says above 5000 rpm it is not smooth at all, and it sounded like it was surging. He's not mechanically minded, so it was a little difficult to understand exactly. But it definitely sounded like he was running too lean, which an air leak would also cause.

[koolaid_kid]

Yeah, Rusty, before he installed the new filter he had no problems either. But he had a tough time with the install because it did not fit quite right.

[rustybronco]

is the filter properly oiled? what do you mean did not fit quite right? mine fit the air filter "holder" just fine though i had to tweek the tab in the housing where the air filter assy hooks at the top of the air cleaner housing. is there foam at the top of the air filter assy for the filter to seal up against it?

[koolaid_kid]

He said he oiled it. He also said that there was about a 1/4" gap that he filled in with the gasket.
He claims that the box was loose with the old one, but is "tight" now.
I don't think he put foam on top, which may be the problem. I'm trying to talk him into putting foam, but he is resisting.
Also, he is an engineer, so he thinks he did it right.
Not a slam on engineers per se, I am one also. But we tend to think that we are always right. LOL

[rustybronco]

He said he oiled it. He also said that there was about a 1/4" gap that he filled in with the gasket.
He claims that the box was loose with the old one, but is "tight" now.
I don't think he put foam on top, which may be the problem. I'm trying to talk him into putting foam, but he is resisting.
Also, he is an engineer, so he thinks he did it right.
Not a slam on engineers per se, I am one also. But we tend to think that we are always right. LOL

As long as he didn't over oil it someone may have enriched it to compensate for the gap or ? before, tell your engineer friend his air/fuel ratio is probably off and to do plug chops. also suggest to him they were engineered with a foam seal and hint to him to find a more durable replacement for the foam, that should keep his inate engineering abilites intact.

[koolaid_kid]

As long as he didn't over oil it someone may have enriched it to compensate for the gap or ? before, tell your engineer friend his air/fuel ratio is probably off and to do plug chops. also suggest to him they were engineered with a foam seal and hint to him to find a more durable replacement for the foam, that should keep his inate engineering abilites intact.

LOL. I love it.