Hawk tune up, top speed, and general musings.
 

Well it's coming up on 600 miles so I figured I was past the break in tune up time. The valves and chain were loose, and oil change was long overdue, and the muffler was rubbing the tire at full suspension compression.

The muffler was simple, just a trip to the hardware store for a longer bolt and 5 washers. The 520 O-ring chain had stretched alot, I was actually concerned about riding it lastnight. But 2 turns on each adjustment screw fixed that. The oil was remarkably clean, I figured it would have a gray color, and there wasn't any metal in the screen. So I'm real happy about that.

I had set the valves at .005" for the break in and I figured they'd be tighter now but they were actually looser. I set them to .003" and hopefully won't have to worry them for a while. I also added 1 washer to the carb needle for a total of 3, but haven't test ridden it yet. One of the intake nuts fell down into the sprocket cover so I had to pull the shifter and cover off to retrieve it. >:(

Yesterday I checked the top speed with GPS and the stock speedometer is way off. In the heat of the day it ran 58mph and 63mph in the cool night air. Also I'm impressed with the brakes. I popped over a hill on an unfamiliar paved road and had about 30 feet to turn right or left, so I locked up the rear wheel momentarily and grabbed a handful of front brake! There might be a small hole in the seat from my sphincter tightening up.. :lmao:

She's running pretty good considering you are geared low. :tup:
So how's the new leg training going? I'm still amazed at the technology.

What is the app you are using (is it Live mobile location and ...... or is that something they are trying to sell you)?

Just says "GPS Speedometer" on Google play store.

I'm not running out of gear at all, running out of power. This thing makes nothing on the top end. I can actually take off faster by not letting the gears wind out.

The leg is doing great, when it learns a new activity it never forgets it. And just like the Cyberdine Systems technology it can't be shut off, I can power it down but it's still on and still recording. If it learns how to charge itself we're all in trouble.. :lmao:

From my experiences, even though the engines do tend to mostly break in around the 500 mile mark, it can take upwards of 1000 or so before everything is fully broken in. Especially on that last little bit of top end. Even so, what Jerry said, and what you said, are both accurate. You ran out of gear because you are running past the powerband via RPM. If you went even taller out back it would pick up more top speed by shifting where you are sitting in the RPM range in 5th. Stepping down from a 45 to a 43 rear on my last Hawk made a big difference in top speed by placing the RPMs lower into the stronger part of the power curve at those given speeds. You do start to notice a good hit in the acceleration department

Even though my head porting opened up a bit on the upper end of the rev range, I can tell that the carb size is a small limiting factor, but the cam profile is still going to keep this motor a bit flat on the top end. That is why I can run up to the 65-70mph mark usually with little effort, but the 70-75 range it starts to fall off and struggle, and anything past 75 takes a total planetary alignment and perfect conditions. If I geared up a bit more it is likely my top speed would change very little, but how it pulled at those speeds would be very different. I just don't want to lose the acceleration that I do have in the lower gears to achieve that.

I am considering seeing what it takes to make a 14 tooth front work. I know the 13 tooth is a bit tight, but unlike a 17t 428 sprocket and chain, I can still remove and install my sprocket cover with ease. That tells me there is a little room to play with, and I have no issue removing material from it if it will allow it to fit. That would open up the door to front sprocket swaps so I can easily change between road only and better off road gearing.

Well I know I'm not changing that 33 tooth rear sprocket until it's absolutely necessary lol. But I will go ahead and order a 13 tooth front sprocket just to see if I like it. I haven't been off roading it as much as I thought I would and first gear is really low, I have to shift into second after just a few feet. Damn thing should come with a 6 speed transmission.

Also the seat has gotten more comfortable for me because I'm making myself sit further forward, feels like I'm sitting on the handlebars though.

Gonna test ride the carb needle change in just a few, it was just too damn hot out there. 86° and really humid.

The verdict is still out on adding a 3rd washer to the needle. Just took it for a little spin and really couldn't tell any difference at all. Guess I'll have to take it for a longer ride tomorrow and see if it affected top speed, plug color etc.

Well the verdict is in on the 3.5 washers. Due to inclement girlfriends and nasty weather I hadn't gotten a chance to go for a long ride until yesterday. I think I've found the sweet spot. It's running better than ever now. No hesitation off idle and pulls strong throughout the midrange. The valve adjustment probably helped some too. I haven't had a chance to do plug readings, but the pipe is putting off less heat and the snap crackle pop on deceleration is almost completely gone.

I got the idea from I believe MyBike? The guy with the customized Magician. He put 4 washers on the needle and didn't go really big on the main jet, and raves about how well it runs. The reason I say 3.5 washers is because the local hardware didn't have the thinner washers I originally bought and this one is about 1.5 times thicker.

So with lots of trial and error I'm at .45mm pilot jet, 3.5 washers on the needle, and a 110 main jet with 2 turns on the mixture screw. And it's really running well, the exhaust note even sounds a little different if that makes any sense. Now should I drill the pilot to .5mm, or put it on the shelf and start over with the Mikuni clone?.. Hahaha! :lmao:

Why not buy the simple “first tune kit” and or go to a pumper carb using same type of carb
Both are more economical then changing to mikuni and pumper gives a gain st only a little more $

https://rover.ebay.com/rover/0/0/0?m...2F303077495104

https://rover.ebay.com/rover/0/0/0?m...2F303169447550

Good old Tako, always trying to make a sale Haha! Why would I need a "first tune kit"? The only thing I could possibly need is a 112 main jet and I can get it delivered in 2 days. And the bike is running great now, so what advantage would I get from a pumper carb when I'm running a stock head? If you wanna do something useful find me a better camshaft or a head that's already been decked ported and polished with better valve springs. :tup:

All you need to do is invest in a $20 rotary tool and some burrs and get busy. ;) I can confirm the TT250 head is a better casting and less restrictive on the exhaust side. Decking can be done manually with sand paper on a flat surface and a little elbow grease. lol We are only talking about taking 1mm off the head. You can even use a thinner head gasket if you don't want to machine the head. We have one member that installed the TT250 head and thinner gasket and found an improvement with no modifications to the head.

I've already got the dremel and all the necessary goodies, and just this morning I priced a TT250 head at $85 plus shipping. I'd have to order some measurement tools but I should have them anyway.

My my.. :lmao:

Perhaps I was a little rude with him when I commented on doing something useful, but I just get tired of him plugging his wares on posts that aren't relevant. I definitely don't need a first tune kit and I was joking about starting over with the Mikuni clone. And I think some of his kits are a definite value, but just ease up on spamming every post.