Correct Air Filter

My question may be naïve but my 1982 KZ750 N1 came stock with a plastic frame and oiled foam type air filter which I did not get with the bike. I have been having trouble getting the bike to run well- slight misfire on low to mid acceleration and a slight engine surging while cruising at any speed.
Have checked out EVERYTHING (electrical system, had carbs rebuilt by "old school carbs", all stock jets, carbs sync'ed by me, pilot jets adjusted, valve clearances good, compression above 120 on all four, ignition system completely gone over, NO vacuum leaks anywhere. Is it possible too much air is getting introduced by using what I am being told is the correct pleated paper filter for that model?

Thanks.

Kerry.

It's possible. The stock air cleaner is a foam sleeve (see www.powersportswarehouse.com/p/Kawasaki#...0-N1-1982/080113C-14 ) and plenternz.com/product_info.php?products_...f42e5ef9e3b4d2faefcb . So if you are using a non-stock filter it may be passing more air or less than the stock unit. Ed

A misfire is not going to be related to a minor air filter difference. That's most likely related to to an electrical issue or more drastic carb issue.

BTW, my 750E has a paper air filter and it runs perfectly (all stock).

I've been wondering if there would be any benefit to switching to the stock foam air filter. The airbox diagram at partzilla for the 81-83 750H seems to indicate that the paper filter is for USA models & the foam was for the Canadians, so is the USA paper filter an EPA thing?

ps: any benefit other than being able to clean a foam filter & not having to buy a new paper filter every time.

What do your plugs look like? They should all be a tan/white color. The symptoms you describe sound more like the bike is running rich. A darker brown/ black on the plugs would confirm.

martin_csr wrote: I've been wondering if there would be any benefit to switching to the stock foam air filter. The airbox diagram at partzilla for the 81-83 750H seems to indicate that the paper filter is for USA models & the foam was for the Canadians, so is the USA paper filter an EPA thing?

ps: any benefit other than being able to clean a foam filter & not having to buy a new paper filter every time.

I tried foam UNI filters for a while and they dried up on the inside and started crumbling into the engine.

Alcohol vapors might have an effect, maybe? It sure seems to affect everything else.

Was that a nos Uni or a new recently mfg'd filter? The foam ends on an old stock air filter of mine crumbled.

It was 17 years ago. I bought them new, probably from Dennis Kirk. They only lasted a few years. I cleaned and oiled them with uni brand products per instructions, but they still crumbled.i don't know how long d k would have had them on a shelf.

Okay. Thanks. I've been wondering about the oem foam filters for a while but the subject rarely comes up. I'll probably stick with paper.