Well I found a Sunoco gas station not too far with 94 octane pump gas. I completely drained my fuel tank again. I refilled the tank with the 94 octane pump gas and added 2oz. of the super 104+ ocatne booster. KNOCK ALL GONE! I'm running the TB (honda trail bikes) 88 light bore kit. I've been told the compression is higher than alot of kits ( 13.5:1). I am amazed at the difference in power. That little bit of spark knock really robs your power. The jetting is perfect from idle to WOT. It runs clean and strong no hesitation, pops, or lag anywhere. I crack the throttle open in second gear (with 15/37 gearing), from almost a dead stop and I barely caught myself before I landed on my back. Suprised the heck out of me! Thanks to FAB5 and everyone who helped with their advise. :YEAH

 

you can make it better if you fatten it up
i run powroll kit and its 13:1
i run premium pump gas no knocks or pings
but i also run an xr100 carb on mine
octane makes the bike run richer, fatten it up and you can run regular gas in
it without problems
the bore kit takes a little to get used to but when you do youll love it

 

all i have to say is...
I TOLD U SO. I TOLD U SO!!!

hahah i wouldnt lie to ya man. glad u got it handled.

 

Just to let everyone know. I've been running the gas and octane booster now for a few weeks and the bike runs perfect. It got run pretty hard last weekend and there is still no knocks. Thanks again to all!

 

woooohoooo :YEAH

 

I thought higher octane made it leaner.

 

I still don't see why such high octane is needed to keep your 50 from detonating. I have almost a full race setup and mine runs perfect on 90 Octane gas.

 

The 13.5:1 compression is the reason for high octane fuel.

Lower octane fuel can ignite from compression and heat alone, not even needing a spark . (hence the spark knock or pre-detonation)

The higher the octane rating in fuel , The harder it is to ignite, in return eliminates pre-detonation or spark knock.

 

I know what it is dude, I'm just saying there is no reason for his 50 to be detonating the way it is. I don't remember a trailbikes kit making 13:5:1 compression. I have a Dragon Racing kit and full race cam and mine runs just fine with 90 octane. If using 94 octane is solving the problem great but I still think there is something else going on. Is the timing in the 50 set right. Did he use the wrong gaskets causing such a high compression ratio?

 

eddie, yours is fine because u have the XR70 head. the combustion chamber of that head is twice that of a 50 head. therefore resulting in a lower compression ratio. the trailbikes kit IS in fact 13.5:1. ive measured it many times. if u doubt my intelligance, tell yer buddy ron to measure everything and calculate the compression ratio. i gaurantee he will come up with the same number.

 

Xidium more octane makes you richer not leaner
your making the fuel itself richer by adding the octane
i dont remeber what carb your running ect ect ect
but your just riching it up to stop your knock
cheaper to jet the carb i run 13:1 0n pump gas no knocks either
although the 70 head it is true will flow more the squish band
shouldnt be that much different it isnt in the older bikes and i would guess it isnt in the newer i havent set them down and measured,but the 70 flowing more will make it richer
theres formula's around the net to give you a base line for what you should be runing on jet sizes you should have a 70 carb and intake so you can change both jets and yeah a 70 head would be good too the more flow the more go
by the pictures you can see the difference in sizes