BP6HS spark plug clearance issue?
- Thread starter chistoso
- Start date
If you haven't installed it yet, do it and take wrench (14mm/socket) and rotate the crankshaft with the magnet nut (clockwise). Do it slow just in case it hits the piston, which I don't think it will. If it does you can either add a head gasket or install a washer on the plug.
I have one in my Atlas build, It fits fine. The engine does have a straight head, not a slant head. I doubt that the head style would make any difference though.
both my old bikes ran this size plug.
I had also lapped both heads down to raise comp.
This was on a grubbee 70cc they did clear but mind you it was bloody close.
Like OP said, check the gap before install. Fit plug and turn the motor over via the 14mm nut behind the magneto cover a couple of rotations. If it gets stuck part the way thru you know it hits.
Just keep in mind though when you thrashing the ass out of it that the piston may have the ability to creep a tad higher than in the barrel and could possibly knick the plug.
I dont think you'll have any dramas though dude.. go for it!
I had also lapped both heads down to raise comp.
This was on a grubbee 70cc they did clear but mind you it was bloody close.
Like OP said, check the gap before install. Fit plug and turn the motor over via the 14mm nut behind the magneto cover a couple of rotations. If it gets stuck part the way thru you know it hits.
Just keep in mind though when you thrashing the ass out of it that the piston may have the ability to creep a tad higher than in the barrel and could possibly knick the plug.
I dont think you'll have any dramas though dude.. go for it!
yes the b6hs has a slightly lor reach than the stock china plug.
BUT, if you remove the head (I'm referring to a slant head here) and look at how far the china plug screws into the head, you'll laugh.
The china plugs electrode is actually shrouded by the head because it doesn't reach into the combustion chamber far enough. yes, it works, but you are loosing a little spark energy because it's shrouded by the head.
The b6hs will reach into the combustion chamber a little further, won't be shrouded and will actually give you a SLIGHT gain in power and a better idle because the fuel burn is better.
just be safe and put the plug in it, and turn it over by hand. it shouldn't hit the piston, but you never know.
it's better to be safe than sorry.
BUT, if you remove the head (I'm referring to a slant head here) and look at how far the china plug screws into the head, you'll laugh.
The china plugs electrode is actually shrouded by the head because it doesn't reach into the combustion chamber far enough. yes, it works, but you are loosing a little spark energy because it's shrouded by the head.
The b6hs will reach into the combustion chamber a little further, won't be shrouded and will actually give you a SLIGHT gain in power and a better idle because the fuel burn is better.
just be safe and put the plug in it, and turn it over by hand. it shouldn't hit the piston, but you never know.
it's better to be safe than sorry.
If you have a slant head, be careful with the projected plugs. They clear as long as the ground electrode isn't facing downward towards the piston. If the electrode is facing the piston, it will hit on my engine and close up the gap.
