Comp valves and springs.

[Miniwood]

I ordered valves and springs from comp racing.
Both of the new springs are the same number and length. Briggs calls for different numbers and one of the old springs was shorter ( A full 1/4 inch) than the other.

There was no top retainer on the springs so they could have worn down

 

[minidragbike]

You suppose to also replace the valves as well with aftermarket versions. That's your problem.

 

[Miniwood]

I did get just exhaust valve. I noticed The head was slightly thicker. was hoping it wouldnt hit the head. It didnt.
Lapped the valves,,, Very good seal.
Why new valves?

You suppose to also replace the valves as well with aftermarket versions. That's your problem.

 

[minidragbike]

I did get just exhaust valve. I noticed The head was slightly thicker. was hoping it wouldnt hit the head. It didnt.
Lapped the valves,,, Very good seal.
Why new valves?

Aftermarket are made the same, and stronger for more RPM. Basically made for modifications

 

[Miniwood]

Lost pressure bad. 65lbs.
Pullled piston last night. Rings are great small gap.
Not sure where ive lost pressure.
Valves are the only place left. But i have lapped them very well.
Thought a stiffer spring would help.

Head gasket new and no leAks?

About to put old springs and exhaust valve back in the engine.

 

[hemigremmy]

Is the valve lash not set and it's holding one of your valves open a tad and letting the pressure bleed off?

 

[pro69nova]

I ordered valves and springs from comp racing.
Both of the new springs are the same number and length. Briggs calls for different numbers and one of the old springs was shorter ( A full 1/4 inch) than the other.

There was no top retainer on the springs so they could have worn down

I sell comp cams the valves, which motor are we talking about.. ?

 

[minidragbike]

Is the valve lash not set and it's holding one of your valves open a tad and letting the pressure bleed off?

I think you might have found the problem

 

[Miniwood]

The only way to adjust the valve is to grind the bottom off of it. There is no lash adjustment.
130202 flathead.
I will check the gap.

Is the valve lash not set and it's holding one of your valves open a tad and letting the pressure bleed off?

 

[Miniwood]

130202 flathead kool bore.
I asked for a slightly heavier spring with a stock rod.

I sell comp cams the valves, which motor are we talking about.. ?

 

[minidragbike]

The only way to adjust the valve is to grind the bottom off of it. There is no lash adjustment.
130202 flathead.
I will check the gap.

You have to get your grind on!

 

[Miniwood]

Bing bing bing,,,, No gap. Apparently when i lapped the valves they seated deeper in the valve seat. There is no gap between the valve and tappet ,,,,they are probably not closing all the way.
How much gap?

You have to get your grind on!

 

[minidragbike]

Bing bing bing,,,, No gap. Apparently when i lapped the valves they seated deeper in the valve seat. There is no gap between the valve and tappet ,,,,they are probably not closing all the way.
How much gap?

What ever the can company recommends

 

[Miniwood]

.005 intake and .009 exhaust.
Didnt have a feeler guage that small. So i used a newspaper .0025 fold it over .005 fold it 4 times .010 . Lol
Runs great!!!!

What ever the can company recommends

 

[Richard Trotter]

If you are using a stock cam, it is hard to get a compression reading. The "easy spin" feature allows the valve opening to overlap ( exhaust valve is already opening when intake valve closes). This is to make it easier to start and decrease kickback.

 

[Miniwood]

Iwas shocked how easy it was to spiin after putting in new rings. They were gapped very tight.

If you are using a stock cam, it is hard to get a compression reading. The "easy spin" feature allows the valve opening to overlap ( exhaust valve is already opening when intake valve closes). This is to make it easier to start and decrease kickback.