Discouraging final assembly and test run for Hawk 250

[OneLeggedRider]

Well Tuesday I decided to finally get the Hawk running. We started with adjusting the chain. The crappy swing arm flexes and adjustment bolts suck. When you would get the tire positioned properly and proper chain slack, every time you tighten the axle bolt the tire would move towards the chain and and the chain would be too tight. After doing this little dance 4 times we put a pry bar in the sprocket and finally got it right.

Next was the valve adjustment, both valves were screwed down tight with zero lash, which I kind of expected.

Then we installed the rear brake lever, battery, and shifter, and changed the oil with Rotella 15w-40 JASO. The shifter is a fragile little thing that I can see bending very easily.

On to the test run. After charging the battery and installing the fuel line we put some gas in the tank and turned on the petcock. Gas poured out the overflow hose and I figured the float was stuck or the needle wasn't seating properly. No, the drain screw wasn't tightened.

After a few attempts it started on full choke, and would eventually idle at half choke with the idle screw really turned up. But after 25 minutes of running in a heated garage it would not idle with the choke off, even with the idle screw turned all the way in!

So now it will sit until I get my carb and exhaust. Because I read up on everything I expected this, but it's still disappointing to see how poorly made these things are and how little the factory cared about initial setup. My first job was an assembler and the Japanese bikes were much higher quality, and ready to run. Suzuki being the worst of the big four was still alot better than this.

[JerryHawk250]

The trick to adjusting the chain is to snug the axle bolt up a little and use the adjusters to alien then finish tightening the axle bolt.

[OneLeggedRider]

The trick to adjusting the chain is to snug the axle bolt up a little and use the adjusters to alien then finish tightening the axle bolt.

Haha! I am a MMI graduate and worked as a tech in shops for 5 years. Even just trying to snug the axle bolt a little was causing the tire to pivot left. I think this is because the cheap swingarm expands/gets wider as you loosen it. Definitely aggravating to say the least.

[DualSport]

Yep you'll never get the PZ30 carb to idle with open choke, and only full or half choke after it's ran a while. The pilot jet is still unidentified.

I had to ride a while full or half choke and then open it up and use throttle/needle to keep idle slightly above what it's suppose to be else it'd stall. If it stalls it usually dries the chamber and you gotta do a few kicks(I haven't replaced the dead stock battery yet) full or half choke with needle a little lifted..

Even with a Mikuni clone you might get a different pilot size, but it's a compatible pilot so you just order one..

[JerryHawk250]

Haha! I am a MMI graduate and worked as a tech in shops for 5 years. Even just trying to snug the axle bolt a little was causing the tire to pivot left. I think this is because the cheap swingarm expands/gets wider as you loosen it. Definitely aggravating to say the least.

Well dang son, need to go back for a refresher course. :p Just kidding. I'm guessing these precision machines aren't exactly made the same. lol Hopefully the next time won't be such a pain. I know the first few time I had similar problems too.

[OneLeggedRider]

I might pull the carb and adjust the idle mixture screw. I read somewhere it's set from the factory at a half turn out, when it should be a full turn and a half out which is the standard for any carb. If that doesn't help I might drill the pilot, which we were taught NEVER to do and see if it nets better results.

Either way I'm buying a good carb and jet kit. I just figure it wont hurt to play with the old one in the meantime and I'm bored lol.

[JerryHawk250]

My stock PZ30 wasn't to bad on its initial run. Just had to adjust the idle speed. But first run out I could tell it was running way to lean. Once I gain access to the jets and idle mixture screw I got it running real good. My PZ30 came with a 98 main and 40 pilot jet. I replaced the main with a 110 main, shimmed the needle with 2 thin washers and adjusted the idle mixture 1 1/2 turns out. After that I could start it with out using the choke. Once I gutted the cat and mod the airbox I swapped out to a 115 main. I only upgrade to the carb I have now because of the head work and wanted something a little more free flowing. Here's a video after I did the carb mods on the stock PZ30.
https://www.youtube.com/watch?v=EzeiiRjdeis

[OneLeggedRider]

Well dang son, need to go back for a refresher course. :p Just kidding. I'm guessing these precision machines aren't exactly made the same. lol Hopefully the next time won't be such a pain. I know the first few time I had similar problems too.

I've actually considered that to be honest. I'm retired now and have alot of free time. And any graduate of Motorcycle Mechanics Institute can sit in on all the classes free of charge for life. And I graduated in '95 so I'm sure alot has been updated for the newer machines.

[JerryHawk250]

I've actually considered that to be honest. I'm retired now and have alot of free time. And any graduate of Motorcycle Mechanics Institute can sit in on all the classes free of charge for life. And I graduated in '95 so I'm sure alot has been updated for the newer machines.
I think that would be fun go sit in on a few of those classes.

[JerryHawk250]

I might pull the carb and adjust the idle mixture screw. I read somewhere it's set from the factory at a half turn out, when it should be a full turn and a half out which is the standard for any carb. If that doesn't help I might drill the pilot, which we were taught NEVER to do and see if it nets better results.

Either way I'm buying a good carb and jet kit. I just figure it wont hurt to play with the old one in the meantime and I'm bored lol.

When you open it up check to see if they still install the 40 pilot jet. I still have my stock carb with jets that I know works collecting dust. ;)

[Megadan]

Now you see why I complain about the rear swing arm so much. Even by the cheap standards it is built by, it is pretty terrible.

The pilot jet was still a 40 in my new bike's carb Jerry.

The idle mixture is set at like 3/4 of a turn out, which is about as lean as it can possibly be set. The needle jet is also permanently fixed in a lean position, and the main jet is still a 98, also lean.

Yes, the shifter is also a cheap crappy part, which is why most of us put on aftermarket ones. The brake lever is a little more durable, but only just, and sticks out a bit too far from the bike.

I could go on lol. Yet, for some reason I still enjoy this cheap little bike.

[pete]

I might pull the carb and adjust the idle mixture screw. I read somewhere it's set from the factory at a half turn out, when it should be a full turn and a half out which is the standard for any carb. If that doesn't help I might drill the pilot, which we were taught NEVER to do and see if it nets better results.

Either way I'm buying a good carb and jet kit. I just figure it wont hurt to play with the old one in the meantime and I'm bored lol.


you could use someone else's setting or set it for your bike..
I have found changing the jets changes the air screw setting.
so what jets is the someone else running..same as you ?
you can see it on a A/F gauge... what I use to jet my bikes..
I set my bikes to be slightly on the rich side..

this is what I do.....
Get the motor hot.. operating temp..
choke off .and idling about the right rpms..
turn the air/mixture screw in/out till you get the highest
idle rpms... then back it in 1/8 of a turn...

then set the idle on the throttle stop...


..

[ChipToothy]

When you open it up check to see if they still install the 40 pilot jet. I still have my stock carb with jets that I know works collecting dust. ;)

Out of curiosity I'm going to crack open my stock PZ30 and have a look around.
Your cold start and idle is better than my warm start and idle, nice job!



*Curiosity= it's about to rain and snow for 2 days and I'm already bored.. :tdown:

[Megadan]

Out of curiosity I'm going to crack open my stock PZ30 and have a look around.
Your cold start and idle is better than my warm start and idle, nice job!



*Curiosity= it's about to rain and snow for 2 days and I'm already bored.. :tdown:
Thats because it is jetted properly.

[pete]

one thing to take into account when jetting ..
if you are using jetting info from someone else
where do they live... what temps are there..

Yamaha's come standard with 2 main and pilot jet options..
a bike sold in England has different jets to a bike sold in Australia..
bike sold in England will have a richer pilot and leaner main the
bike sold in Australia will have leaner pilot and richer main..
The richer pilot gives easier starting in a colder climate..
but the A/F ratio of both jet combinations is about the same..



...

[timcosby]

My stock PZ30 wasn't to bad on its initial run. Just had to adjust the idle speed. But first run out I could tell it was running way to lean. Once I gain access to the jets and idle mixture screw I got it running real good. My PZ30 came with a 98 main and 40 pilot jet. I replaced the main with a 110 main, shimmed the needle with 2 thin washers and adjusted the idle mixture 1 1/2 turns out. After that I could start it with out using the choke. Once I gutted the cat and mod the airbox I swapped out to a 115 main. I only upgrade to the carb I have now because of the head work and wanted something a little more free flowing. Here's a video after I did the carb mods on the stock PZ30.
https://www.youtube.com/watch?v=EzeiiRjdeis

same for me jerry. i probably put 150 miles on it befor i tore into the carb. i have never had a problem adjusting the chain so i dont know whats going on there.

[timcosby]

i hit a raccoon or armadillo with my shifter and it bent really bad but it straightened back out just fine with out cracking so thats a plus!

[512customs]

Right out of the box my bike didn’t want to run for shit, wouldn’t idle for more then a minute and a half on its own. After about 30 minutes run time I ordered a new carb (amazon China Mikuni) and slapped it on right away. Runs real good now.

[OneLeggedRider]

I know a thing or 2 about jetting and reading the plug and setting the air mixture screw. But it's a real simple carb and you guys have done most of the legwork so I'll probably slap a 110 in there, see how it does and go from there.

[JerryHawk250]

110 is a good place to start on a completely stock engine. Your issue sounds like you just need to adjust the idle mixture. The pilot jet is big enough. I found raising the needle helped too.

[OneLeggedRider]

110 is a good place to start on a completely stock engine. Your issue sounds like you just need to adjust the idle mixture. The pilot jet is big enough. I found raising the needle helped too.

Trying that today, I don't have the main jet but I can do the idle and needle adjustment and maybe it will idle then lol.

[JerryHawk250]

Trying that today, I don't have the main jet but I can do the idle and needle adjustment and maybe it will idle then lol.
Nothing wrong with the stock carb. They are tunable except for being able to fine pilot jets for them. But you really don't need too. Guys like you , Megadan and I have experience in carb tuning. But for some it's not so easy. But they all end up learning after playing with them.

[OneLeggedRider]

Nothing wrong with the stock carb. They are tunable except for being able to fine pilot jets for them. But you really don't need too. Guys like you , Megadan and I have experience in carb tuning. But for some it's not so easy. But they all end up learning after playing with them.

If I can get the stock carb to work with only buying a jet or 2 I definitely will. I was dead set on getting a new carb but your cold start video definitely impressed me. And the only engine mods I'm planning is the pod filter and exhaust so maybe the 110 will be enough.

[JerryHawk250]

If I can get the stock carb to work with only buying a jet or 2 I definitely will. I was dead set on getting a new carb but your cold start video definitely impressed me. And the only engine mods I'm planning is the pod filter and exhaust so maybe the 110 will be enough. With the pod filter and exhaust you will need to bump it up to at least a 115.

[OneLeggedRider]

Good advice and that's what I'll order.

[DualSport]

I did commutes a while on a stock PZ30 with a Mikuni 110 needle/main jet. 1.5 turns out on mix screw and had to pull needle till warm up, but it was good the rest of the day. Really cold weather takes some more kicks or turns but same procedure..

For me idle/needle screw would either be too low or two high or just under too high but still required like 800-1000 idle for some minutes before I could run half or no choke idle..

[OneLeggedRider]

I started a new thread for the carb which I will update accordingly. But yeah, the fuel mixture screw was fully seated. I'm still sitting here in disbelief.