« previous next »
Pages: [1]   Go Down

Author Topic: fuel / gas type  (Read 968 times)

0 Members and 1 Guest are viewing this topic.

bolo

  • Guest
fuel / gas type
« on: May 14, 2009, 04:04:52 AM »
hey all...i've got a 78' sohc cb750 chop and was told that i should run unleaded petrol with the lead additive as its an old engine etc....could someone veryify if indeed i have to? many thanks!
Logged

Offline Hush

  • Finally they realise that I am an
  • Really Old Timer ...
  • *******
  • Posts: 6,761
  • "Lady, I've heard it all before"!
Re: fuel / gas type
« Reply #1 on: May 14, 2009, 04:09:27 AM »
I've asked this question myself and it seems there are a few answers.
(1) we do not need to run the additive in our bikes.
(2) 91 is fine for our older bikes unless you have very high compression and then 95 would be better.

Hope that helps, for my 1979 CB650Z I have found 95 the better option but I don't know what major work the PO did to the bike so maybe the motor had some major work and it has pretty good compression??
Logged
I think the thing I most like about motorcycling is the speed at which my brain must process information at to avoid the numb skulls who are eating pies, playing the ukulele, applying make-up etc in the comfort of their airconditioned armchairs as they make random attempts to kill me!!!!!!!

bolo

  • Guest
Re: fuel / gas type
« Reply #2 on: May 14, 2009, 04:15:40 AM »
hmm...righto...i think 95 is standard unleaded over here (pomme land) but heard a rumour that if i run this the valves etc will go to #$%*....i'm sure no addititive will be ok in the short term but i've got a fairly unique lump and want to keep it for awhile  ;D (its a yoshi lump)...
Logged

Offline Gordon

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 12,114
  • 750K1, 550K2
Re: fuel / gas type
« Reply #3 on: May 14, 2009, 06:57:35 AM »
All of the sohc4's were made to run on Unleaded fuel.  It wasn't in widespread use at the time of their design, but Honda knew it was coming soon. 
Logged

Offline Alan F.

  • We remember the Night Rider, and we know who you are.
  • Really Old Timer ...
  • *******
  • Posts: 7,341
Re: fuel / gas type
« Reply #4 on: May 14, 2009, 07:04:05 AM »
If you've got a high compression engine you should run higher octane fuel.  A coworker lost the engine in his Hemi pickup last week, the autopsy showed one piston had seperated from the rod at the wrist pin, and the other 7 were in bad shape.  He liked to buy the cheaper 87 octane fuel.  78,000 miles.   Poor idea.   

I'd personally worry about more than just your valves if you run the wrong fuel.
Logged

Offline Gordon

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 12,114
  • 750K1, 550K2
Re: fuel / gas type
« Reply #5 on: May 14, 2009, 07:11:31 AM »
Quote from: Alan F. on May 14, 2009, 07:04:05 AM
If you've got a high compression engine you should run higher octane fuel.  A coworker lost the engine in his Hemi pickup last week, the autopsy showed one piston had seperated from the rod at the wrist pin, and the other 7 were in bad shape.  He liked to buy the cheaper 87 octane fuel.  78,000 miles.   Poor idea.   

I'd personally worry about more than just your valves if you run the wrong fuel.

Hopefully somebody who has gone through the trouble of modifying their sohc4 engine for high compression would know this, but then I guess someone could easily buy an already modified sohc4 and not know that it needs high octane.
Logged

Offline alltherightpills

  • Expert
  • ****
  • Posts: 1,330
Re: fuel / gas type
« Reply #6 on: May 14, 2009, 09:01:30 AM »
I have always wondered about running E10, which has been pretty standard at the pump around here for as long as I've been driving.  I know that the higher the ethanol content, the more corrosive it is, but does running 10% ethanol have any effect on our engines? 

I usually run the nonethanol just to be sure.  It is 87 octane, which, according to the owners manual, should be fine. 
Logged
78 550K
77 550K (in pieces)
71 500K0 (in pieces)
Pages: [1]   Go Up
« previous next »