Intake duct alternatives?

I currently have an all stock 1981 KZ650H1 (CSR) with standard air box, cylindrical filter, carbs, etc. The intake ducts are at their end, and I've tried just about everything to restore them to usable softness. I've tried to get a replacement set, but haven't had much luck finding the parts. Hence my question, has anyone custom ducts successfully before? I've seen a few ideas using rubber hosing (~1.5'' ID) with band clamps, couldn't tell if that would work out that well or not. I've also toyed with the idea of pods, but have resisted against going down the debacle of rejetting, etc.

See www.z1enterprises.com/airbox-hoses-4-kz6...750-zn700-zx750.html

Those unfortunately don't fit the H1 (only h2 & 3) despite being listed incorrectly on several websites that they do. The ducts are about 30% bigger than the needed parts 14073-1053/1052.

You could get the 650-H2/H3 ducts, then cut donuts from radiator hose to make up the difference at the carburetor inlets. You may have to use 2 donuts per duct. and I would use ss band clamps to secure the ducts.

Another option is to get CV carburetors from a later csr or a 750-4 along with new -1032 ducts.

Martin's suggestion definitely sounds workable, but you might be able to get the right parts (sort of). The site below *seems to have* the RH boots available. If you can get 4 of those, I'm pretty sure you can just flip two of them over to use on the left side. It seems to me they'll match up with the carbs just fine and the only difference will be the angle of the boot ends inside the airbox. You could always trim those if it seems necessary.

www.cycle-parts.com/Products/367077-14073-1053.aspx

Barry

Martin, I literally just bought a backup set of 81 csr carbs ($60 ebay!!!) otherwise I'd go the whole new airbox/carbs from 750. I like the donut idea and have a set of the 650-h2 boots already with no use so doesn't hurt to try. Stratman, website is showing all sold out, but I'll give em a call tomorrow to see; you're indeed correct about either duct side working. Maybe they'll have some after all.

Here's a post/idea I'm after currently from another user a year ago (good info for anyone in a similar situation as me!). I'm hoping that the radiator hosing's OD will fit the air box holes ID. Any ideas on creating a flange for the inside of the airbox like the real ducts have? I was toying with getting reinforced water hosing (double walled) and partially separating the outer wall to heat and harden while leaving the inner wall straight.

www.kzrider.com/forum/3-carburetor/59983...memade-air-box-boots
www.kzrider.com/media/kunena/attachments...0/Carbboots001-8.jpg

If I can get any of these solutions to work without having to rejet, I'll do a write-up since these issues are only going to be more and more common as parts dry up.

retka wrote: Stratman, website is showing all sold out, but I'll give em a call tomorrow to see; you're indeed correct about either duct side working. Maybe they'll have some after all.

Really? I'm seeing the LH part sold out but the RH part looks like it's available. I could be missing something.

I just checked my garage because I have a spare airbox but the boots on it are the wrong kind (and pretty crusty). I thought I might be able to help you out.

Anyway, please do keep us posted on your eventual solution. Being a fellow '81 CSR owner, I'm very interested to know how you make out.

Barry

Now when I search by part number, I see what you're talking about. If you search by model > air cleaners it shows both parts as discontinued. I was able to add to cart so that's promising. I'll give em a call in the morning though to double check and report back if in luck. Thanks for the info.

On a side note, I'm going to be messing with the ducts 14073-1032 in the mean time but have a full set I don't need. If anyone is in need of the set for the H2/H3, holler.

The 650-CSR has the same airbox as the 750E/H and the 14073-1032 ducts fit that airbox & CV carbs.

Using donuts w the -1032 ducts is probably the simplest solution. assuming of course that you can't find the stock ducts anywhere --- they're supposed to be NLA & have been for quite a few years.

Ebay Air Duct

I saw that duct, but one won't do much good & it's expensive --- $35 for one is ridiculous.
There was a full set listed this year for around $130. ouch. Those are the only 2 listings I've ever seen of the 81 650 ducts.
Z1Enterprises.com has a full set of the -1032 ducts for about $50 plus shipping.

I just found a gently used set along with stock airbox for $30 off the Fbook kz650 riders group including the ducts. I am currently working on fashioning the ducts utilizing the 1032 ducts. I found out that radiator hosing with a 1.5'' ID will both fit inside the 1032 ducts as well as fit over the kz650 csr carbs. Seems like a possible work around and I'll update on Friday/Saturday if my fabricated duct works out along with a guide with sizing/etc.