I just installed a grubee skyhawk gt5 - interesting

[KTOKTO]

It will probably clear up once the head is sealed. If not I would raise the needle clip one notch. It might just be a bit rich, and becoming a bit too rich once it warms up. hopefully it isn't like the ones I was shipped that only had 1 notch on the needle.

I just swapped in the skyhawk motor. The carb, ignition and everything else is what ran perfectly on the ebay motor. I haven't ran it enough to figure out what is going on. I'll post some more findings later this week when the gasket comes in. Thanks again!

 

[Street Ryderz]

I am curious if you are comparing apples to apples,Is the cheap ebay engine an A type piston the same as the skyhawk? If they are I dont think you will find much difference since when grubee changes some thing like the current cylinder back to round ports at the flange,The older or previous castings still in stock get used up as off branded engines and they have made alot of little changes over the last decade thats why there is now many varients IMO !

 

[gary55]

I pipe cutter, file and terry cloth might be useful for adding notches.

I tried it with the dremel. Trashed the first one, the second one worked

 

[Street Ryderz]

I tried it with the dremel. Trashed the first one, the second one worked

The thin clay looking cut off wheels work well for that.I like to put it in the small collet for rotary tool and spin it against a fine jewelers file to get the depth and width just right!

 

[gary55]

I used the thin cut off wheel, and it worked for my experimenting. Probably should invest in some jewelers or gunsmith files.

 

[Street Ryderz]

I used the thin cut off wheel, and it worked for my experimenting. Probably should invest in some jewelers or gunsmith files.

So many options and ways of doing the same thing it's interesting to see how others achive the same goal!

 

[gary55]

So many variables on the engines too. I found if you remove one of the two base gaskets from these new A80 engines and use the round aftermarket head the squish gap comes in at .81mm. The exhaust port on them is 1mm higher than the gt5 so it should still be slightly advanced.

 

[butre]

I used the thin cut off wheel, and it worked for my experimenting. Probably should invest in some jewelers or gunsmith files.

gauged needle files are a ripoff. torch tip cleaners will work on anything that's not steel or harder and cost f*** all for a full set

 

[Street Ryderz]

So many variables on the engines too. I found if you remove one of the two base gaskets from these new A80 engines and use the round aftermarket head the squish gap comes in at .81mm. The exhaust port on them is 1mm higher than the gt5 so it should still be slightly advanced.

Thats interesting is the intake the same because if you messure the gt5's it's around 5 mm lower than the B type engines, Just like the difference of 2mm on some crank circles.

 

[gary55]

The gt5 is a B type engine. 38mm stroke, B type piston, FM 80 rod. The A80 uses a ZL40mm rod, B type piston, and two base gaskets. They both use the 69.6mm jug.

Now to the exhaust height diff. I referred to It wasn't even a GT5 I was comparing with the A80. I misspoke. It was actually a PK80 jug at 70.5mm. that is probably where the 1mm diff. came from, well that and me not paying closer attention.

I have a tendency to get too many irons in the fire. Like to think I would have caught that before assembly. Still glad you called me on it.