ok i had a blown head gasket got my head and cyclinder milled to match installed new rings since it was down felt it was a good ideal. got it all back in the frame hit the start button and it now sucks your hand in on the exhaust where it should blow it off it will not hit or even try to hit. my question is where is the timing mark on the magneto/flywheel? and what direction should my cams be when im tdc on piston? i know there is the two lines on both cam gears and two notches one notch locks in the cam the other does not. please help asap need to get this going for my son. i need to know if the cam lobes should be out or in? thanks mike

 

Bring your piston to TDC, install the cams with the little lines on the cam gear in the horizontal position. Make sure the cam lobes are facing out away from eachother.

Should work great!

 

done this several times i only get a little bubble of blue flames out of the exhaust. does it have a compression stroke? or as long as the cams are point out on the lobes and lines are even on the cam gears your ok? it was running great when i tore it dwon but had a blown head gasket

 

what do you mean "does it have a compression stroke"???

Plugs fire every rpm, regardless if its a compression stroke or exhaust stroke.

there is no flywheel mark for timing, but there is however a timing "hole" in the crank that a crank locking bolt should have been installed into prior to any disassembly. using a lock bolt in the timing hole on the crank insures you that it is at TDC prior to disassembly, remains there during work, and is still there when you go back together. Being at TDC, the cam sproket marks are then set level across the horizontal, parrellel with the head surface that the head cover goes on, with cam lobes facing out away from eachother. The locking bolt is installed through a hole just below the water pump cover that is plugged with an 8mm bolt that uses a 6mm hex key to remove.

Did you properly hone your cylinder prior to reassembly? if not, the new rings will not break in properly to match the bore shape.

I hope your timing isn't off so far that you crashed your valves with your piston and bent anything.

 

i had the timing as you say and it does nothing it has plenty of compression well you can not hold your finger over the plug hole so thats alot of compression what should it be when not running just turning over to test compression? thanks for the help. my compression gauge says 70 pounds this is turning it over with the starter not running. i had the cylinder and head machined and honed properly. i had this motor off and installed a headgasket last month and did not check the gead it was warped so i pulled it off and had the work done really got my puzzled now.

 

I usually get 120psi compression when turning over with starter, without disabling auto compression release mechanism. if you are only getting 70psi then something must be wrong somewhere

 

Did you for any reason, like a lightened flywheel, take the magneto off of the flywheel? They will go on in any position, I did this when I did my flywheel and it would not fire, just throw flames out the exhaust. So I took it off and lined up the pickup with the keyway on the crank, and she works awesome.

 

i never even took the cover off the flywheel. i just pulled the motor back off and pulled the head no bent valve i have it laying on the bench and it is holding gas in the valve area fine no leaks there are no cracked rings good seal on the head gasket. if i hold my hand over the baffle in the back the motor feels and sounds like it has no compression. sometime i get a bellow sound out of the back im lost here someone tell me what it is please. i have built several motors and never ran into this before. really sound like it is out of time.

 

i'd start by rechecking the timing make sure the piston is at tdc then make sure the cams are in place as dsnut said. and then try again, in the past lots of uys had them out 180 and hadthe same problem you have.

 

how do you get them 180 out? if the piston is at the top 100% both cams are pointed out. i even took the allen bolt out nder the water pump so i couldlock the crank in postion. i know the timing marks on the cam gears got them level they only fit the cam one way man this thing is puzzling me. anyway if you can tell me how i can have it 180 out ok. thanks again. mike