Lito
Race Dog
When my bike was stock (stock exhausts/ EPC/ SAS intact/stock jetting), I was generally getting 10kays/litre. Needless to say that it really hurt when it came to filling the beast - the smile that a KTM delivers would be taken away temporarily at the pumps - and particularly at R10plus / litre.
The best I ever got was closer to 13kays/litre - trundling along at 100km/h on a dirt highway. Now, I may be a tad overweight, but thats awful and pathetic.
Cue: Head 2 Wind jetting kit, with Unifilter.
I ordered 3 of the kits from Ken in the States and sent 2 to Bushclown up in KZN. I installed mine, looking for that elusive "3-4mpg increase". With the cost of the kit, I calculated I should break even on it, within 30-50 tanks of juice (depending on Rand/S and Rand/Litre and Throttle Twist/Tank)
At the tech day we had for LC8's, I had everything installed and set the carb floats to 3.5mm. The reasoning for this was that it made for a crisper response through the rev range, and also allowed the bike to not stumble in the whoops when attacking them. Stock float height is 3mm.
Of course, when I measured them, they were way off (stock), and I had to be very gentle bending the tang to adjust the float height. Buttoned her up, and my economy was settling at around 2-3% better. To say I was dissapointed is an understatement of note. After many tanks of gas and starting to just accept the crap economy, I had a call from Bushclown which absolutely spurred me into action. Here this lad was getting closer to 16-17km/l at a cruising speed of around 140 - and the bike was loaded.
I asked my favourite Orange Crusher (John aka CPModem) for advice, and after much technical discussion it turned out that I had held the carbs incorrectly when setting the float height. Essentially the carb flat surfaces had to be vertical and the floats just just seating when measuring. This was vastly different to my method which was holding them perfectly level and then going for it.
Interestingly enough, the rear float came wonky from the factory with the right side at 2.5mm and the left part of it at 3.5mm. No matter how I tried to fix its positioning, its just a warped piece - while the front float was perfect.
What I did on the service:
1) Replace spark plugs - KTM has the cheapest spark plugs in town
2) Correct the valve clearances within spec (exhaust was tighter than allowance)
3) Clean unifilter and reoil (it was pretty much ok before starting)
4) Clean out airfilter (and removed a tablespoon of sand)
5) Set the floats to 3.5mm
6) Cleaned the carbs out of west coast sand, and installed a fuel filter
Result:
1) Two up - at 140km/h - 20-25% increase in fuel efficiency / stiff headwind
2) Single up - at 140km/h - 35% increase in fuel efficiency/ stiff headwind
3) Two up - on single and double track - 28% increase in fuel efficiency.
4) Single up - on sand gunning it - 55% increase in fuel efficiency (previous worst was 40kays in Atlantis, on 12.5litres of juice)
Very very pleased! I still have an exhaust leak which when fixed will further improve fuel economy, and theres still a piece of sand which prevents the rear float from fully seating (evidence of backfiring through the rear exhaust - read: unburnt fuel)
Plans: replace everything to stock to see what the economy will be.
This means: stock thermonuclear reactor exhausts, stock jetting, removal of unifilter and refitting on air intake, reinstate the EPC/ SAS.
After this I will have a better benchmark to work from and perhaps I can raise the economy to 15km/l - this will be a massive improvement and clearly increase the stock range significantly.
Will report back.
The best I ever got was closer to 13kays/litre - trundling along at 100km/h on a dirt highway. Now, I may be a tad overweight, but thats awful and pathetic.
Cue: Head 2 Wind jetting kit, with Unifilter.
I ordered 3 of the kits from Ken in the States and sent 2 to Bushclown up in KZN. I installed mine, looking for that elusive "3-4mpg increase". With the cost of the kit, I calculated I should break even on it, within 30-50 tanks of juice (depending on Rand/S and Rand/Litre and Throttle Twist/Tank)
At the tech day we had for LC8's, I had everything installed and set the carb floats to 3.5mm. The reasoning for this was that it made for a crisper response through the rev range, and also allowed the bike to not stumble in the whoops when attacking them. Stock float height is 3mm.
Of course, when I measured them, they were way off (stock), and I had to be very gentle bending the tang to adjust the float height. Buttoned her up, and my economy was settling at around 2-3% better. To say I was dissapointed is an understatement of note. After many tanks of gas and starting to just accept the crap economy, I had a call from Bushclown which absolutely spurred me into action. Here this lad was getting closer to 16-17km/l at a cruising speed of around 140 - and the bike was loaded.
I asked my favourite Orange Crusher (John aka CPModem) for advice, and after much technical discussion it turned out that I had held the carbs incorrectly when setting the float height. Essentially the carb flat surfaces had to be vertical and the floats just just seating when measuring. This was vastly different to my method which was holding them perfectly level and then going for it.
Interestingly enough, the rear float came wonky from the factory with the right side at 2.5mm and the left part of it at 3.5mm. No matter how I tried to fix its positioning, its just a warped piece - while the front float was perfect.
What I did on the service:
1) Replace spark plugs - KTM has the cheapest spark plugs in town
2) Correct the valve clearances within spec (exhaust was tighter than allowance)
3) Clean unifilter and reoil (it was pretty much ok before starting)
4) Clean out airfilter (and removed a tablespoon of sand)
5) Set the floats to 3.5mm
6) Cleaned the carbs out of west coast sand, and installed a fuel filter
Result:
1) Two up - at 140km/h - 20-25% increase in fuel efficiency / stiff headwind
2) Single up - at 140km/h - 35% increase in fuel efficiency/ stiff headwind
3) Two up - on single and double track - 28% increase in fuel efficiency.
4) Single up - on sand gunning it - 55% increase in fuel efficiency (previous worst was 40kays in Atlantis, on 12.5litres of juice)
Very very pleased! I still have an exhaust leak which when fixed will further improve fuel economy, and theres still a piece of sand which prevents the rear float from fully seating (evidence of backfiring through the rear exhaust - read: unburnt fuel)
Plans: replace everything to stock to see what the economy will be.
This means: stock thermonuclear reactor exhausts, stock jetting, removal of unifilter and refitting on air intake, reinstate the EPC/ SAS.
After this I will have a better benchmark to work from and perhaps I can raise the economy to 15km/l - this will be a massive improvement and clearly increase the stock range significantly.
Will report back.
