Adjusted Valves - Hawk

[ChrisWNY]

So I did my first valve adjustment - engine has about 150 miles on it so I figured now was a good time. Pulled the spark plug and found TDC by using the kick starter. I adjusted the exhaust to .005" and the intake to .004" using my feeler gauge set (I know some have said 0.004" on the exhaust and 0.003" for the intake, but my feeler gauge only goes down to 0.004"). Those valves were REALLY tight from the factory. I had to use a small pair of vise grips to loosen those gap adjustment screws before they would turn by hand. Finally I got 'em loose enough to turn by hand then adjusted using the feeler gauges, and wrenched the nuts down tight, then double checked again to make sure the proper gap was set.

The engine fires up quick and runs great as usual - I notice a lot more "clicking" noises from the engine compared to before. Just wanted to make sure this wasn't a sign that there's too much of a gap.

[JerryHawk250]

Tappy valves are happy valves.

[o2jmpr]

Worry when the clicking stops.

[ChrisWNY]

It's definitely running a little rich now...doesn't bog but at full throttle, but the RPM's don't come up enough so top end speed is limited to about 55mph. Spark plug is pretty dark as well. Engine is running cool though, but I'm definitely going to pull the carb, drop down to a #115 main jet and raise the snap ring to the middle slot of the needle instead of the 2nd lowest slot. Bottom fuel adjustment screw on the carb probably needs to come in a full turn or so as well. Valves definitely sound good though...nice and slappy.

[o2jmpr]

Drop down to a 115? Maybe I missed it in some of your other posts but I assume Then you must have done something like aftermarket exhaust and pod filter or the like to be running that big of a main. I’ve just never heard of anyone running larger than 115 before is why I ask.

[JerryHawk250]

I have to agree. A 115 will be about perfect with the mods you have.

[ChrisWNY]

Originally Posted by o2jmpr

Drop down to a 115? Maybe I missed it in some of your other posts but I assume Then you must have done something like aftermarket exhaust and pod filter or the like to be running that big of a main. I’ve just never heard of anyone running larger than 115 before is why I ask.

I have the aftermarket exhaust and opened up the airbox. The #120 was running too rich no doubt (very noticeably rich after adjusting the valves), even the #115 seems a little rich at full throttle so I may downsize to a #110. The bottom-most fuel mixture screw is out 1.5 turns which was the Mikuni factory setting...clip is back on the middle slot of the needle (also the default setting from the factory).

The engine runs well otherwise...no bogging, and idling is perfect, right around 1200 RPMs. I'll run with the #115 for awhile and will likely adjust down by the weekend. Ran into a glitch when I reinstalled the Mikuni carb and started the engine...it flooded out quickly and all sorts of fuel ran out that overflow line. Turns out the float was hung up on something, easy fix.

[MickeyNew]

I did my first valve adjustment on my Hawk today. They were both very tight with no room to get the feeler gauge in. When I was done, I was amazed how quickly the engine fired. After a short ride, I had to turn the idle speed down twice to calm it down. Very positive change from this.

On word of caution for those of you that don't own a bike lift. It you remove the large round cover with the bike on the side stand, oil runs out!!!

[PANDEMIC]

ok so valve adjustment question.

So I removed the plug to see the top center T mark.

I removed the side cover to access the bolt to rotate the flywheel counterclockwise stopping on the T the valves where super tight so loosened and set them to .002

I rotated the flywheel 3 times stopped on the T mark and the valves are so very loose rotated it one more time again stopping on the T mark its back at .002

so when should I set the valves when it is on the loose setting or tight setting?

[NzBrakelathes]

Originally Posted by ChrisWNY

So I did my first valve adjustment - engine has about 150 miles on it so I figured now was a good time. Pulled the spark plug and found TDC by using the kick starter. I adjusted the exhaust to .005" and the intake to .004" using my feeler gauge set (I know some have said 0.004" on the exhaust and 0.003" for the intake, but my feeler gauge only goes down to 0.004"). Those valves were REALLY tight from the factory. I had to use a small pair of vise grips to loosen those gap adjustment screws before they would turn by hand. Finally I got 'em loose enough to turn by hand then adjusted using the feeler gauges, and wrenched the nuts down tight, then double checked again to make sure the proper gap was set.

The engine fires up quick and runs great as usual - I notice a lot more "clicking" noises from the engine compared to before. Just wanted to make sure this wasn't a sign that there's too much of a gap.

https://www.ebay.com/itm/303028071070

This tool set with gaskets might just be the answer if your feeler gauges hasn't got the right sizes - being metric has a much smaller increments.

Intake I usually do 0.06 (just under 3 thou) exhaust 0.08 (just over 3 thou)
I test with 1 size smaller and that should glide thu easily and 1 size bigger and that goes thru with force showing me the size I used is within range.
Sorta old fashioned Go no GO idea etc

[NzBrakelathes]

Originally Posted by jeffrey

Remove the sparkplug check though the hole that the piston is at the top of its stoke. With the T mark lined up. both valves should be lose. Then set them to spec.

The valves will reveal where the stroke is at
Just before and after TDC on the wrong stroke the intake closes exhaust opens
If it’s doing that you’re on the wrong TDC stroke

[timcosby]

Originally Posted by PANDEMIC

ok so valve adjustment question.

So I removed the plug to see the top center T mark.

I removed the side cover to access the bolt to rotate the flywheel counterclockwise stopping on the T the valves where super tight so loosened and set them to .002

I rotated the flywheel 3 times stopped on the T mark and the valves are so very loose rotated it one more time again stopping on the T mark its back at .002

so when should I set the valves when it is on the loose setting or tight setting?

remove spark plug too so it wont push itself past the mark cause by compression.

[Megadan]

Originally Posted by PANDEMIC

ok so valve adjustment question.

So I removed the plug to see the top center T mark.

I removed the side cover to access the bolt to rotate the flywheel counterclockwise stopping on the T the valves where super tight so loosened and set them to .002

I rotated the flywheel 3 times stopped on the T mark and the valves are so very loose rotated it one more time again stopping on the T mark its back at .002

so when should I set the valves when it is on the loose setting or tight setting?

You set your valve lash at TDC on the exhaust stroke. What these guys seem to be forgetting is that on a 4 stroke engine there are two TDC positions, one during compression, one during exhaust. You need to set your valves for TDC on the compression stroke.

Turn the engine over until you get to the T where the valves are very loose. Set them to spec in that position.

Once you do that, rotate the engine over and watch the intake valve (carb side). Once you see that valve open (rocker pushes it down) keep rotating it until you see the T mark again and line it up - this will be TDC on the compression stroke. Double check your valve lash, it should be what you set it to previously.

[NzBrakelathes]

Originally Posted by ChrisWNY

I had to use a small pair of vise grips to loosen those gap adjustment screws before they would turn by hand. Finally I got 'em loose enough to turn by hand then adjusted using the feeler gauges, and wrenched the nuts down tight, then double checked again to make sure the proper gap was set.

I really recommend my tool set - you will find doing valve clearances sooooo much easier or your money back.

Just ask Jerryhawk!

[JerryHawk250]

Originally Posted by NzBrakelathes

I really recommend my tool set - you will find doing valve clearances sooooo much easier or your money back.

Just ask Jerryhawk!

Tool does make it much easier.