TOPIC:

i have a 1977 kz750b2 so far i've put about $600 in it, it still doesn't look like alot, should i use 93 octane? i put new rings in so it should have original compression??????????

Post edited by: cratgo, at: 2005/10/13 23:12

cratgo wrote:

i have a 1977 kz750b2 so far i've put about $600 in it, it still doesn't look like alot, should i use 93 octane? i put new rings in so it should have original compression??????????

Welcome to the site!

Did the bikes originally require high octane? I can tell you that when I first got mine, I tried higher octane and it ran much worse than on 87 (US). I have since learned all about/how/why regarding octane.... from now on it's the crap stuff for me....

My bike ran the same on 93 as it did on 87(stock engine no mods). What the higher octain gas did do was foul my plugs quick. Regular works fine for me.

Tried 93 once, never again, bike ran like crap. I'm sticking with the 87.

higher octane just means cooler and cleaner running engine. and o yea.$$$$$$$$. cheap stuff works just as good if not even better.

kawasakikid38 wrote:

higher octane just means cooler and cleaner running engine. and o yea.$$$$$$$$. cheap stuff works just as good if not even better.

This is the second time I've heard someone refer to higher octain gas as "cleaner". When I used it in my bike I found that it produced more carbon. Is this because an engine with certain mods is able to burn the carbon higher octain produces while my stock engine cant?

All octane does is inhibit Detonation, if your bike doesn't knock or ping then you don't need to run a higher % of octane. I have heard the cleaner or more power line for years but I being an informed person know better that that!. 87 or so will be fine for your B2 Twin, unless you have detonation then you need higher Octane rated fuel

750B only has 8.5:1 compression stock, so regular 87 octane should work great, it has been fine in the three 750 twins that I have had so far. My 9.5-10:1 765cc twin motor may be a different story, but it's not done yet, so I don't know. I just hope I can still kick start it, since it no longer has an electric starter

As soon as oil companies hung the "Premium" tag on high octane gas, folks assumed that it must be better. Commercials have you believe it is cleaner/better/will give you greater performance.

If you have 8.5:1 compression and use Premium gas, you will soot your spark plugs and waste your money. Octane inhibits combustion for high compression engines which keeps these engines from pinging. A 750 twin doesn't have high compression (unless modified) so stick with regular which will burn cleaner and give you better performance!

This point has been beaten to death and if someone finds a good article or writes one, please for to Stein to place in the "articles" section.

wiredgeorge wrote:

...This point has been beaten to death and if someone finds a good article or writes one, please for to Stein to place in the "articles" section.

I agree. I found a couple:

Article 1 from Motorcycle.com

Article 2 from TotalMotorcycle.com

sorry wiredgeorge for beating a dead horse, i did NOT know the compression so i wasn't sure, this is my first moto, i've only rebuilt honda 3 wheeler stuff, kinda lost.

No problem! This is such a common issue that the articles noted should be placed where they can be read with general information.