Bad Backfiring after Valve Cover Gasket Replaced

  • KZQ
  • Away
  • Administrator
  • Walking Behind the Corn May Not Be All That!
More
27 Apr 2016 06:57 #723222 by KZQ

Mac55 wrote: I had the cross wedge type, got it reset and everything is running well. Took it out for about 3 hours last night and so far no fresh oil on the engine which is better than I could say before.

One question I do have is could replacing that gasket affect performance? I've noticed a huge difference in how the engine feels when accelerating and I have a lot more pull in 4th and 5th than I did before. I don't understand how just messing with the valve cover could have affected performance that much though. I just did it because I suspected it was leaking oil. Any ideas?

Sure! A properly adjusted cam chain could make that difference.
Bill

www.KZ1300.com
Riders:
1968 BSA 441 Shooting Star, 1970 BSA 650 Lightning, 1974 W3, 1976 KZ900, 1979 KZ750 Twin, 1979 KZ750 Twin Trike, 1981 KZ1300, 1982 KZ1100 Spectre, 2000 Valkyrie, 2009 Yamaha Roadliner S. 1983 GL 1100
Projects:
1985 ZN1300

Please Log in or Create an account to join the conversation.

More
27 Apr 2016 10:50 - 27 Apr 2016 10:52 #723259 by loudhvx
Did you change the cam timing? I didn't think you did. The gasket thickness won't change timing by any amount that can be felt in performance.

If the timing was off by a tooth, and you re-timed it, then it will make a difference.

If the old valve cover gasket was torn and air was leaking into the air suction ports, that would cause the backfires, but won't affect performance. (It affects combustion in the exhaust system, not inside the cylinder.)

It could be you had some bad connection at the coils or other wires, and you disturbed them somehow.
Last edit: 27 Apr 2016 10:52 by loudhvx.

Please Log in or Create an account to join the conversation.

More
30 Apr 2016 12:40 #723785 by Mac55
Alright, new concern. When the engine hits about 4-5000 rpm it sounds like the cam chain is hitting the engine casing or something like that. I've noticed no difference in performance since I did everything else, just the sound, which just started. Is it possible the tensioner didn't reengage correctly when it was reset? Should i be concerned? Going to take the whole assembly off and make sure it's clean and working later today hopefully but wanted to see if anyone has any other ideas.

Also does anyone know where I can get more information on the '83 750 F1? I have the Clymer for all 80-83 KZ 750 twos and fours but as far as ive seen they don't even mention the F1 in the book despite it being an '83 four.

Please Log in or Create an account to join the conversation.

More
01 May 2016 11:17 #723943 by pete greek1
Replied by pete greek1 on topic Bad Backfiring after Valve Cover Gasket Replaced
It should say what models are covered on the outside rear cover of the manual
Pete

1980 LTD 1000..,1976 LTD 900, have the 1000&900 now. the rest are previous= 1978 KZ 650 B.., 1980 Yamaha XT 500..,1978 Yamaha DT 400.., 1977 Yamaha yz 80..,Honda trail ct 70.., Honda QA 50...5-1/2 hp brigs & straton CAT chopper mini bike...3-1/2 hp mini bike (WHEN GAS WAS ABOUT 45 CENTS A GALLON)!!!!

Please Log in or Create an account to join the conversation.

More
01 May 2016 13:19 - 01 May 2016 13:38 #723962 by 650ed
No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationYou really need to buy a Kawasaki Service Manual rather than aftermarket junk manuals. The part number for the KZ750-F1 manual is 99924-1035-03; the part number for the KZ750-F1 Owner's Manual is 99920-1183-01. Ed

99924-1035-03




99920-1183-01


Attachment 00003a-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20.jpg not found



Attachment 00003d-2-3-4-5-6.jpg not found


1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Attachments:
Last edit: 01 May 2016 13:38 by 650ed.

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum