Mods and top speed input request

[Digger]

More mistakes, I give up!! One step of the clip on the needle is .040.

[o2jmpr]

Thanks Digger for the updates!

After today, I really don't know if I'm rich, lean or right. Bike seems to run the same between 1/4 to 3/4 with either 1 or two .032 washers. I believe I have lost some top speed somewhere along the way. Maybe it's temps, humidity, tire pressures I don't know. Kinda hard to tell when you're a big guy riding a 229 and wringing it's neck all the time.

Where I'm at now is easy starting without any choke. My bike has always been that way.
Idle ramps up a bit when warm but not enough I have to mess with idle adjustment. I can't tell any difference in mixture screw setting between 1 turn out and 3.5 to 4 so I settled on two.
I get good throttle response throughout the range. It's crisp with no hesitation and pulls well.
Fast roll off when going down a hill or downshifting producing some noticeable exhaust popping but not banging backfiring.

I'm not a good plug reader. I haven't done a WOT chop, just pull the plug often to have a look. Threads are black with no oil or soot. Insulator is white and clean at the level of the threads but has some caramel color tinting as it nears the tip. The gap bar across the top (what do you call that) is dark discolored black and grey but not white.

I should just quit changing things and ride the damn thing until it won't go anymore.

[Digger]

Originally Posted by o2jmpr

Thanks Digger for the updates!

After today, I really don't know if I'm rich, lean or right. Bike seems to run the same between 1/4 to 3/4 with either 1 or two .032 washers. I believe I have lost some top speed somewhere along the way. Maybe it's temps, humidity, tire pressures I don't know. Kinda hard to tell when you're a big guy riding a 229 and wringing it's neck all the time.

Where I'm at now is easy starting without any choke. My bike has always been that way.
Idle ramps up a bit when warm but not enough I have to mess with idle adjustment. I can't tell any difference in mixture screw setting between 1 turn out and 3.5 to 4 so I settled on two.
I get good throttle response throughout the range. It's crisp with no hesitation and pulls well.
Fast roll off when going down a hill or downshifting producing some noticeable exhaust popping but not banging backfiring.

I'm not a good plug reader. I haven't done a WOT chop, just pull the plug often to have a look. Threads are black with no oil or soot. Insulator is white and clean at the level of the threads but has some caramel color tinting as it nears the tip. The gap bar across the top (what do you call that) is dark discolored black and grey but not white.

I should just quit changing things and ride the damn thing until it won't go anymore.

Again sorry for the confusing info, guess I'm getting old.
One thing I find odd is not having to use the choke to start. In my opinion a correctly tuned carb should always require enrichment on a cold start. My Hawk is very lean at idle and I don't think it would EVER start cold without the choke, it needs to run 5 mins before it will idle without the choke at least 1/2 on. I'm satisfied with the 2 spacers on the needle and the 110 main jet on my stock engine and exhaust. My next project when I have the carb off is to drill out the pilot jet so I will be at 1 1/2 turns out on the idle mixture screw.
I'm a big guy as well. I won't ride my bike over 50 mph with 16-50 gearing, in my opinion just too hard on the engine.
Good luck and have fun with your Hawk!

[o2jmpr]

I put the 45T rear on this morning and gained a whopping 4MPH. It was not worth the effort but it's also not worth changing back.

Top speed now is 62mph WOT on the flats. Whatevs..... I concede. There is a torque loss, but I don't really care anymore. I'm just gonna ride.

The second washer is going back in because my spidey sense tells me the engine is getting too warm. It's noticeably warmer around my legs.

[ChrisWNY]

In this hot/humid weather I've never had to choke the Hawk to get it to start. It will usually fire and run in a split second even after sitting for 24 hrs or longer. Once the temp drops into the 60s (or lower), I have found that a half-choke is necessary to get the engine running. I'm probably running a little rich at idle however.


Dark-colored threads with a tan/gray electrode on the spark plug is probably a good sign that you're not running the engine too lean or too rich. 60-65mph on the 45T seems about right (at 7k-8k RPM's, more or less) for top speed. If you're doing mostly road riding you probably want to run on the rich side. For reference, I had to go one slot lower on the clip on my Mikuni needle, not sure what that equates to as far as shimming the needle on the OEM China carb.

[Megadan]

On most non CV style carbs the threshold for choke/no choke is usually around 60 degrees give or take a little. It doesn't mean that they don't need it, just that the air is thin enough that you can get away with it. I usually half choke cold starts between 60 and 80 degrees for up to 30 seconds to a minute tops. 50-40 degrees = full choke start for first 30 seconds, half choke for a minute or two of run time. Below 40, usually I need a re-jet, and I full choke idle for at least 1 minute and half choke for 2-3.

As far as the 17/45. It is a good "all rounder" gearing setup for light-medium trails and highway use. Not quite high enough to make it a great highway bike, not quite low enough to make it a great off-road bike. It is that nice warm mushy grey area where it becomes the jack of all trades. It's good enough to move my also large butt around and up hills decently, as well as tackle the kind of off-roading these bikes were intended for. If you want slow crawling in first gear, then going up a couple teeth out back might be more for you. For reference - 65mph in 5th gear is spinning the motor just under 7000rpm, and it will idle along right at about 5mph in first gear.