Grubee Starfire SuperRat Engine Kit!

how are we looking. im set at the 3rd clip right now. it came stock at the 2nd.

Looks pretty good on my screen...

finally!! now if i could get this thing to start up every time i will be in great shape

Odd with a plug looking like that that it's hard to start. Is it hard to start hot, cold or both? Have you tried choking it?

ya, Sick bike has a shorter reach plug NGK BPM6A abd its shorter on top

My buddy put a extra head gasket in the super rat to make it easer to start, got it started perty easy and he also went to 25:1 oil mix, after about a 2 mile run back it started to loose power coming back home. He said he knew what it was he nedded to tighten the head boults, so when he whent to tighten them one was completly loose and would just spinn. So he gave me the engine thinking he striped the boult down in the engine. Come to find out the long boult wasent tighten down all the way, I checked the other ones and they were not screwed all the way down also. Wo aI got a good engine, ai need a base gasket and aI dont know if I got the bottom ring in right. Anyway I got a SkyHawk slant head 66cc running good, I was thinking about swiching the heads to see what hapends, cause a high compression bilet head cost 75 bucks anr the super rat head looks like it'll give me alot moe compression. What do you think?

when i first ordered my mb engine i ordered a skyhawk 48 cc engine but somehow ended up with the 66cc engine. turns out i think i got the gt5A ( gt5 bottom with a super rat top end) because it has enlarged intake and exhaust ports. i need a new top end and was wondering if i'm correct in thinking i need a super rat top or regular 66cc top? also with my old top end with the enlarged rectangle exhaust port it didn't match up very well with stock small round hole exhaust pipe and round gasket. could that cause any problems and if so where can i find an exhaust pipe with a bigger whole?

rob.smith said:

when i first ordered my mb engine i ordered a skyhawk 48 cc engine but somehow ended up with the 66cc engine. turns out i think i got the gt5A ( gt5 bottom with a super rat top end) because it has enlarged intake and exhaust ports. i need a new top end and was wondering if i'm correct in thinking i need a super rat top or regular 66cc top? also with my old top end with the enlarged rectangle exhaust port it didn't match up very well with stock small round hole exhaust pipe and round gasket. could that cause any problems and if so where can i find an exhaust pipe with a bigger whole?

Click to expand...

yes you need a super rat top end or gt5a top end they are both the same

is there any difference other than the larger intake and exhaust ports? and do they make exhaust pipes that match up to the bigger exhaust ports on these motors?

Just read this huge thread. Whew>
I recently ordered a 49cc top end from Helio/Kyle, (read up on him).
The intake & exh. port shapes are different and sizes are big at the manifold.
They shrink to the regular size & shape at cylinder for timing.
Stud spacing is wide, so I havent seen advertized or gotten to make custom manifolds.
KYLE YOU SHOULD INCLUDE A FITTING MANIFOLD FOR ODD SIZE.


Relative to thread: Could this possibly be a "Rat" top end?
On mine INTAKE is the BIG rectangle
Exhaust is round
(both big) as said
Any thoughts

Nobody mentioned air leak with that white plug... Is that motor toast yet?
When running spray carb cleaner or starting fluid ALL AROUND with little straw attachment (ovoid directly into intake)
Any time engine boggs you have an unwanted air intake in that spot
You need to fix that First You can then try tuning
Reiterating some good advice from threads and pm advice of the best hot rodders here
BAIRD, TACO, MAPBIKE......

PEACE