750 motor hesitating

[Freddy]

Freddie,

......Mikuni Jets?? Do you mean Keihins?? ................ Not that it matters if they fit.

Whatever are the OEM brand of carbies, been a while since I did it. Knew there were really only two possibilities and took a guess, seems I guessed wrong

[Freddy]

how come in ozz you have more choice of fuel

The ethanol legislation introduced into Australia was something like the the company has to sell a certain percentage of its fuels with 10% ethanol. Very different to saying ALL fuel must contain 10% ethanol. Because the 10% ethanol is a bit cheaper its by far the most popular and the companies have no problem meeting this legislated volume. It allows many companies to offer 100% regular beside the 10% ethanol on a lot of bowsers, and none of the higher octane fuels on offer have ethanol in them.

In the city you just need to know what brand petrol stations offer both, and in the country a very small servo in some remote place with limited bowsers will generally just carry the non ethanol standard to meet local requirements as the fuel will be used all manner of rural machinery, boats, etc.

Back on the theme of fitting larger jets, that you have to use ethanol is another reason to consider upping the main jets sizes. The original jets would have been specified to meet an every increasing emissions lean standard, based on non ethanol fuel. My D1 originally definitely ran lean (at sea level, pretty normal temperature/humidity levels). No chance of it starting without using the 'choke' when cold, pretty lame response for rapid overtakes. Ethanol contains oxygen molecules, straight gasoline doesn't. That's why ethanol based fuels create a leaner AFR and not recommended for anything with a carburetor. Naturally all my comments relate to a bike ridden at sea level, with normal range temperatures/humidity levels.

Not an expensive experiment and certainly worth a try to see what you think I reckon. Only an issue if someone is not proficient at pulling the carbies in/out the bike which it seems you have no problem. I can get mine out in 10 minutes these days, about 15 to refit without drama, done it so many times now.

[David Richard]

well it seems that from my brief ride last monday was not a fluke i had time to do about 15 miles this evening and all is well the motor worked very well so thats one more watch ,i remember a few years ago we ran a old merc diesel and that went through a faze of clocking the pre filter up which had been almost growing a bacteria in the tank and pipes but was able to keep on top of that one,but thanks for your thoughts on this ,david

[Freddy]

Good to hear the bike seems to be running correctly now.

Think the 'learnings' here are that completely draining the tank, in the process checking and cleaning the intank filters, should be a routine maintenance task undertaken every few years. Quite a simple procedure when the tank is already off for say checking valve clearances (something I need to do not having checked them for a while).