What's Inside Your Grubee GT5?

[bairdco]

I'm reversing some new Grubee GT5 motors, and found some nice metal surprises inside:

[bairdco]

it's hard to tell from these pictures, but the head gasket was unevenly "torqued," but if you look closely, you can see it's crushed more in two opposite corners than the others.

it also had a different amount of washers under the crappy acorn nuts to take up the space. one had 2 flat washers and a lock, and the rest had one flat and a lock.

[bairdco]

here's a before and after shot of the combustion chamber on the slant head.

the casting is super rough, which could cause hot spots, as well as a nice surface for carbon build-up to stick to.

in the secod pic, i also lapped the head with sandpaper on glass. you can see the uneven-ness in the before pic.

[bairdco]

speaking of awesome castings, here's the fins, before and after:

[bairdco]

here's a shot of the stock steel, shorty intake.

all the welds inside should be dremeled smooth, as well as port matching the flange (no after pics, because i haven't done it yet...)

[Poopyboogin420]

Originally Posted by bairdco

I'm reversing some new Grubee GT5 motors, and found some nice metal surprises inside:

My gt5 needs a new jug, piston and rings because of those bits. My first major learning experience with China Gas quality control. Oh well. Now I know.

[bairdco]

if installed un-touched, right outta the box, you could have some serious problems, including premature engine failure, lowered compression due to metal shavings gouging the cylinder walls and piston, and just all-around poor performance.

i'll post pics of the finished product soon, after i get some new nuts for the head. i ain't using those lousy acorns.

[Poopyboogin420]

Originally Posted by bairdco

if installed un-touched, right outta the box, you could have some serious problems, including premature engine failure, lowered compression due to metal shavings gouging the cylinder walls and piston, and just all-around poor performance.

i'll post pics of the finished product soon, after i get some new nuts for the head. i ain't using those lousy acorns.

You're tellin me. I was lucky it lasted as long as it did. On the bright side, I get to tear into it and do some hands on learning. I'm going to replace the acorns, too. But yeah, that's exactly what happened. I was riding, then ting, ting, no compression.

[rohmell]

Thanks for the pictures, Bairdco, this just reaffirms my 100% anti anything from Grubby Grubee (feh) stance.

It might be a good idea to do a complete engine disassembly. Who knows what kind of nuts and bolts might be bouncing around inside of the crankcase.

[bairdco]

i don't think the problem is Grubee's alone. i've heard of many other engine manufacturers with the same problems.

and, it looks like the skyhawk's gonna be the only engine available (except for old stock) unless the other factories pay off the EPA.