What Next...Carb Mods or Mushrooms?

[Quenton Guenther]

Hi Hal,
Lifters will leave tomorrow morning. Boy they are going fast!
A few comments to consider concerning the head, the compression is too low on all of the NE5 Whizzzer motors. If you check it with a compression gauge you will see numbers between 80 and 90 pounds. The motor needs at least 100 pounds to, start easier, idle smoother, better throttle response, and better gas mileage. If you make the spark plug fit correctly in the head it will also run cooler. If you mill the head, the area near the 2 large head bolts will increase and make a much better seal reducing the chances of a blown head gasket.
I have milled and reworked many heads [over 100], and suggest removing .060" and use a copper head gasket. The copper gasket is thicker than the steel version by .010", so if the head is milled .060", the copper gasket will in effect reduce the difference to .050". The end result will not make it ready for "Bonneville", just put it closer to the correct compression ratio for street use.
On my race motors, I use special heads with reduced combustion chambers and end up with 165 pounds of compression and need high test gasoline. On my street bikes I usually mill stock heads down .065" ~ .070" and try to end up with approx. 110 pounds of compression.

Hope this information is helpful,

 

[Hal the Elder]

I Have No Bridgeport!

HEY Dr. Q:

So do I send my head to you for milling, along with my clutch for rebuilding?

On the other hand, Oscar starts, runs, and idles just fine with the stock compression ratio, and has more power than I need for my preferred casual cruising of the Desert byways at 20-25 MPH!

But if it's absolutely required for me to have my head milled and my clutch rebuilt, then to be accepted as a "right-thinking" member of this Forum, I'll agree to have it done!

HAL the REASONABLE

 

[Quenton Guenther]

Hi Hal & Oscar,

I can help you with the head later. Main issue is to change the lifters for duribility.
I have "jigs" made for my mill to address the spark plug length and the milling process. I also rework the combustion chamber for better flow in the same process, but I suggest you leave the head "as is" until you have approx. 500 miles on the motor. I don't want to quote prices, but it is about half of the average machine shop price, because I don't do this for a living, but just for the fun of it.

Have fun,

 

[Hal the Elder]

Sounds Fair To Me, Quenton!

Now, about the payment for the Mushrooms...what is your preferred method of payment, and how much, including shipping?

I assume the Lifters will take priority over my clutch rebuild...? It will probably take another 4 months to acumulate 500 miles on Oscar!

Thanks...
HAL

 

[Quenton Guenther]

Hi Hal,
I will include an invoice in the package. Simply mail a personal check [please don't waste your money getting a money order]. I will send it via padded envelope to save money on shipping.

Have fun,

 

[Hal the Elder]

That's Just Fine With Me, Quenton!

Sent those two little pieces of steel right to me, and I'll follow your installation and valve clearance instructions!

HAL

 

[Kep1a]

Good call Quenton,
My head gasket started leaking at about 350 miles but only when cold at start up. I found the head was no where near flat and was forced to mill it to make a flat sealing surface. When I realized how much of the spark plug threads were protruding into the combustion chamber I knew that was going to be an issue with the life of the threads in the head. It could also create hot spots that would cause knock problems also known as pinging or detonation.

The replacement plug now fits the chamber perfectly and no threads are exposed to combustion deposits that would tear the threads out of the head while removing the plug for normal maintenance. Re-surfacing the head to be flat again required the removal of about .60 to regain a flat sealing surface. I polished the combustion chamber to remove any sharp edges that may also cause pinging. The improvement in flow will only enhance the engines cooling and overall bike performance. The net effect of these improvements was dramatic on my bike! I only wish Whizzzer had paid attention to the details negating the need for me to do these upgrades.

I would much rather ride than tinker IMHO.

Kep1a