TOPIC:

kk ive got a '76 kz400 which i bought from a co-worker
ran like well (insert adjective here) well i removed carbs replaced bowl o rings removed jets and basically gave them the 24hr soak like ive done on previos successful cleans on different bikes that ive had. well got them re assembled re installed new plugs etc fired right up so im like hell yeah time to ride! , i get to the end of my driveway bout 1/2 mile away. it dies sooooo i push it back to house, and pull plugs fouled bigger than anyhting im like wtf? anyhoo ive replaced 3 sets of plugs just fouled 3rd set after dialing back mix screws to between 1.5 turns and 1.75 turns thought that would help, well it helped a bit but, fouled them, plus burned almost the tip. so to make a long story short rofl sorry bout that, im thinkin perhaps someone in the past may have installed jets that were far to large ? . can someone tell me the jet sizes so i can put the original sizes into this thing? its got original exhaust. original style air filter, essentially a stocker. can someone tell me the original jet sizes i would be ever so greatful. my patience is starting to wear thin on this thing lol thanks ahead of time

carbs themselves and all of its parts are free of apparent defects gaskets are good etc

The carbs came with caps on the pilot jets. Were these reinstalled on reassembly? Second, have you measured the voltage going to your coils? Weak spark is often the reason for plug fouling and THIRD, do you have aftermarket air filters that may have been grossly overoiled? That will cause plugs to foul as well as 4th... wrong heat range plugs. Use only NGK plugs in the heat range recommended by the manufacturer. LAST (5th) check your valve clearances and lube the advance mechanism???? Those 5 things are about the most common reasons for plug fouling I can think of...

thx for reply, i put those rubber plugs back in place, however they may need to be replaced, heres something i didnt post yesterday. i had bought the bike from the original owners son. his uncle had installed carbs from a '78 onto this '76. will that make a difference? as far as i know, the air filter inside the airbox is original spec. the pipes sound as though the baffles have been punched. but other than that as far as i can see this looks to be an original setup. but then again i could be wrong lol:whistle:

I edited Photo size. Randy.

Post edited by: ran429, at: 2006/05/01 01:33

Lucky you, the 78 carbs are easier to find parts for.
WG hit the spot with that one, check that stuff out!

Looks original to me. My 400 had cracks all over the rubber plugs, never made any difference . Not to say you shouldn't check that out...

Thats a ran429 bike!
I think it has alot of potential.

What did you give for it? Cheap?

ran429 wrote:

Thats a ran429 bike!
I think it has alot of potential.

What did you give for it? Cheap?

eh define chesp lol anyhoo the rubber plugs went in waaaaay too easy. are they designed to bea tight fit? ive lots of experience with carbs but these are the first of this kind ive had the pleasure of dealing with heh ive got to figure out what to do on this, when it runs before the plugsa foul heh runs quite well although can smell the gas in the exhaust. id pay wiredgeorge to look into these for me, however im trying to keep costs down at the moment. another question, where can i find those rubber plugs at? most of the carb kits ive seen do not have them and the stealer im afraid to find out what they charge for them:blush:

cause the stealer charged me $10 each for the bowl o rings lol

yamahonkawazuki wrote:

thx for reply, i put those rubber plugs back in place, however they may need to be replaced, heres something i didnt post yesterday. i had bought the bike from the original owners son. his uncle had installed carbs from a '78 onto this '76. will that make a difference? as far as i know, the air filter inside the airbox is original spec. the pipes sound as though the baffles have been punched. but other than that as far as i can see this looks to be an original setup. but then again i could be wrong lol:whistle:

I edited Photo size. Randy.<br><br>Post edited by: ran429, at: 2006/05/01 01:33

sorry bout the photo size. and thanks for all of your help youve been great so far

any idea where i can get those rubber plugs, are they designed to fit tightly? any help yall can throw my way would be greatly appreciated;) or any idea as to what i can use in place of those plugs?

the plugs that your talking about should fit tightly. check with z1 interprise, jeff is awsome to buy from.

did you check your advancer? i had the same thing and i lubed it. cured.

also check for any vacuum leaks

good luck

vacuum leaks would lean it out, sorry.

i still like the advancer mecnaism.again it cured my 650 right away.