Head Gasket Gap On New Engine?

[RPM]

I did put up another post last night before I signed out with the other pics but apparently I'm a newbie and don't have the seniority or benefits the other members do as of yet. Seeing how its a new day I'll try again now.

Sorry about the confusion Pablo, if it confused you it probably will others so I'll call it what it actually is. When I referred to 'x-ray' its actually an 'invert page view' or 'negative' view of the picture. What it does is show maximum contrast of the picture in a different perspective.
What you may not see in a normal picture you may see in a negative state. I used it to show the 'Hotspots' (flaws, imperfections) is what I'm referring to here.

As I stated earlier Pablo, the engine has yet to be fired up. The head is square or true. There is no flaws in it what so ever. The problem orginates in the jug or cylinder. I've since put it back together so we'll see what happens. When I took the head off two of the bolts were so loose I thought they were going to fall out when I tipped the motor upside down.

I don't think I will have it up running this week but probably next. I still have to do some work on the intake tube and heat the exhaust pipe to bend it slightly for a clearance issue. After that I should be good to go.

My buddy from Port Huron Reg is forty-eight. Not that you look forty-eight you just resemble him as you do the actor who played in the movie "Rockstar". Ya ever been up this far North?

RPM

 

[RPM]

So I finally got the engine mounted in the bike and everything dialed in yesterday then took it out for a fifteen mile ride. Everything works great. So if anybody runs across this problem with a new motor take the head off and do a visual inspection for any flaws in the jug or head area, if there are none to the extent of the pictures I've posted here just retorque everything and your good to go.

I have to comment on the performance of this engine compared to the 49cc I bought last December. WOW! What a difference. The throttle response is 100% from bottom end to top. Snappy! The engine just wants to keep screaming no matter how far I twist the throttle. I wonder if taking the dremel tool to the intake tube has anything to do with this?

RPM

 

[drhofferber]

I have bought 2 slanthead motors from zoom. Both has 2 head gaskets. I think it's to slightly reduce the compression so they start easier when new. I removed one of them after my motor was broken in. The clearance was fine but it seemed like the motor was pinging a little so I put the second one back in. It may also be to try to make up for non flat surfaces. If you do lap it in you would have to remove alot of material before any shiming was needed. I was just trying to help you avoid the shipping turn around delay. Esp. since even if it looks good you may have to do it anyway. GL

.junkster..with two head gaskets, what did you torque the heads at...thank you...Dennis

 

[Junster]

Hi Dennis, glad you got your motor going. I torqued the head at 12 ft lbs. After a couple heat cycles you'll have to do it again. After a day of riding check it a 3d time. I'm sure you know this but just in case. Put your torque wrench on a lug bolt or something with it set at 10-15 and click it a few times before you use it to tighten something at that low torque. It lubes the inside of the wrench and makes it alot more accurate.

 

[drhofferber]

Hi Dennis, glad you got your motor going. I torqued the head at 12 ft lbs. After a couple heat cycles you'll have to do it again. After a day of riding check it a 3d time. I'm sure you know this but just in case. Put your torque wrench on a lug bolt or something with it set at 10-15 and click it a few times before you use it to tighten something at that low torque. It lubes the inside of the wrench and makes it alot more accurate.

thank you...that is pounds per foot...right...
thanks again...Dennis

 

[Junster]

ya 12 ft lbs (foot pounds) or 144 inch pounds

 

[drhofferber]

ya 12 ft lbs (foot pounds) or 144 inch pounds

THANKS AGAIN...Dennis

 

[PatMcLJr]

Hi Dennis, glad you got your motor going. I torqued the head at 12 ft lbs. After a couple heat cycles you'll have to do it again. After a day of riding check it a 3d time. I'm sure you know this but just in case. Put your torque wrench on a lug bolt or something with it set at 10-15 and click it a few times before you use it to tighten something at that low torque. It lubes the inside of the wrench and makes it alot more accurate.

You should post that on the tips page, good one.

Pat Jr.

 

[Hiigel]

What you need to know is that the gasket is producing a seal at the mating surfaces, the raised square you see when the head is off. What you show is probably just a flaw in the casting process, and should not bother the works of the motor.

Gary

 

[headtrama]

If you ever looked at a used head gasket you will see there is a small crushed ring where it seals . I true up my cylinders in a lathe so the whole gasket seals and use a better quality head that is flat as well .