driftology
New Member
you wouldnt happen to remember where your idle screws were at by default
Grubee Starfire SuperRat Engine Kit!
- Thread starter Vistaman73
- Start date
bare bones
New Member
Take off the mag plate and follow the wire to where the cdi is. You can screw the wire on or off by going clockwise or counter clockwise respectively.
bare bones
New Member
driftology
New Member
its alive!!! i don't know what fixed it. i wasn't very systematic. but i put the carb back to where i think it was from factory. completely emptied it out and drained what i could from the motor. and threw in a new spark plug just for giggles. i suspect that cns carb might be the issue. im assuming these spark plugs aren't top quality. a quick question to anyone using the super rat. what oil fuel mix ratio are you guys using. ive read on this forum that the ratios in the manual are over kill on the oil. my plug isn't milky brown like it should be. it is pretty dark and oily
bare bones
New Member
With the Super Rat I am using Opti-2 at 1:100. In the other engines I have, I use semi synthetic at 1:32.
driftology
New Member
i think i have figured out how to use the cns carb. i have been reading all over this forum for info but all the threads are conflicting. anyways it idles good i think drops from rev to idle ok i guess. now i need to figure out if im running to lean or rich while at open throttle. how soon after running the motor should i pull the plug to look at it. i took mine out after about 20mins and this is what it looks like. not milky brown thats for sure. im also using 16/1 mix ratio
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Fyling Scot
New Member
Grubee Starfire SuperRat Engine - CNS Carb Tips?
Hey driftology:
Any pearls of wisdom that you have to impart regarding the CNS carb would be most welcome. I am a week in on my first build and I still don't seem to be making any progress with getting the carb right.
I can't get it to idle unless I screw the idle screw all the way in and even then I need to warm it up well. At that point it seems to race more than idle
I have experimented with moving the jet needle up and down by placing the cir-clip washer into the different notches and didn't seem to reach any conclusions.
I have made some adjustments on the mixture screw ( the one on the left which I believe is CW for richer and CCW for leaner ).
The one thing I am wondering about is carb angle. Mine is leaning forward - I have a jack shaft kit and a lightweight road bike frame. I suspect that the angle on the seat tube of my bike is a lot steeper than a typical cruiser and I think the jackshaft tips the engine a few degrees forward as well. I took out the bowl last night and looked at the float mechanism but I wasn't too keen to mess with it. If I could be sure that the float level was an issue I might give it a try.
I am on the 16:1 mixture and I suspect that could be the root of the problems. With that much oil in there the physics of the gasoline might be changed quite a bit such that it is harder to suck through tubes, doesn't vaporize and mix with the air as effectively and doesn't burn as well.
I am tempted to just put up with the poor carb tuning while I burn up the two gallons or so I have mixed and then have a go once I get onto a less oil loaded fuel.
When I do hit those spots on the throttle where the carb is performing it really pulls so I live in hope. In fact my other problem is chain snapping which I tend to put down to the increased power.
Cheers,
Fyling Scot.
Hey driftology:
Any pearls of wisdom that you have to impart regarding the CNS carb would be most welcome. I am a week in on my first build and I still don't seem to be making any progress with getting the carb right.
I can't get it to idle unless I screw the idle screw all the way in and even then I need to warm it up well. At that point it seems to race more than idle
I have experimented with moving the jet needle up and down by placing the cir-clip washer into the different notches and didn't seem to reach any conclusions.
I have made some adjustments on the mixture screw ( the one on the left which I believe is CW for richer and CCW for leaner ).
The one thing I am wondering about is carb angle. Mine is leaning forward - I have a jack shaft kit and a lightweight road bike frame. I suspect that the angle on the seat tube of my bike is a lot steeper than a typical cruiser and I think the jackshaft tips the engine a few degrees forward as well. I took out the bowl last night and looked at the float mechanism but I wasn't too keen to mess with it. If I could be sure that the float level was an issue I might give it a try.
I am on the 16:1 mixture and I suspect that could be the root of the problems. With that much oil in there the physics of the gasoline might be changed quite a bit such that it is harder to suck through tubes, doesn't vaporize and mix with the air as effectively and doesn't burn as well.
I am tempted to just put up with the poor carb tuning while I burn up the two gallons or so I have mixed and then have a go once I get onto a less oil loaded fuel.
When I do hit those spots on the throttle where the carb is performing it really pulls so I live in hope. In fact my other problem is chain snapping which I tend to put down to the increased power.
Cheers,
Fyling Scot.
GearNut
Active Member
You need to enrichen your fuel to air ratio. You are burning too lean. Switching to a 32:1 oil/ gas ratio will help a bit. Even though re-tuning is commonly needed when changing the oil to gas ratio, it is not wise to vary the oil to gas ratio as a tuning aid by itself.
driftology
New Member
should i retune using the air/idle screws on the carb or is it time to move the clip?
GearNut
Active Member
That all depends on how far open you have the throttle when riding. If less than 1/4 throttle then mess with the mixture screw. If over 1/4 throttle then lower the needle clip position towards the pointy end of the needle. Just one position at a time, checking the results each time you move it.
driftology
New Member
sounds good. i will start with the mix screw. its not too often i go past half throttle.
driftology
New Member
made some adjustments. moved the idle air screw in to rich up the mix a little and the plug is getting darker but it is still super dry. the very tip where the prongs and gap are is completely dry and it gets a little moist one side where the prongs are attached to the base of the plug. tomorrow i will try moving the clip down to see it that helps at all. and i will have to add more gas to my mix. i worried about not running 16/1 since this motor barely has 30miles on it. wonderful forum, thanks for all the help everyone.
bare bones
New Member
Anyone blowing head gaskets with the Super Rat? Two blown in one day for me. 
driftology
New Member
I blew one already too. This compression it too high
gasbikes.com is selling them for $299 (i dont know the shipping)
its on the 2nd or 3rd row diwn in the kits menu
it has pics and full details when you click on the pic it is the skyhawk sr
you have to order a 415 chain with it. i cant use the bike chain that comes with it
stay dry
gubba
its on the 2nd or 3rd row diwn in the kits menu
it has pics and full details when you click on the pic it is the skyhawk sr
you have to order a 415 chain with it. i cant use the bike chain that comes with it
stay dry
gubba
Rockenstein
New Member
Anyone blowing head gaskets with the Super Rat? Two blown in one day for me.
Scratching my head trying to figure out how one can blow out aluminum head gaskets
If they are aluminum and they are leaking something like a warped head, improper stud torque or poor mating surfaces is more than likely the cause of a leak.driftology
New Member
I'm not sure what to call it but I get spewing from the head. Both areas that sandwich the gasket are smooth and I'm sure the head was torque properly.
driftology
New Member
I got my super rat from piston bikes. It was much cheaper.
GearNut
Active Member
Smooth is one thing, but are both surfaces absolutely flat?
Any distortion, subtle dips or high spots on the gasket surface, of either the cylinder or head are open invitations to let a head gasket leak or blow out; no matter what the gasket composition is.
Duct tape a sheet of 150 or 200 grit wet/ dry sand paper to a thick piece of glass and gently work the head then the cylinder over it using a figure 8 motion. Keep the sand paper wet with water (1 drop of dish soap to 1 gallon of water works good) to prevent it from loading up with metal.
About every 5 passes turn the cylinder or head 90 degrees so as to avoid favoring one particular area.
Do not take off too much material or you will increase the compression ratio even higher than it all ready is. The goal is to only true up the surfaces. When you first start out you will see where the sanding is only affecting the high spots. You will know when it is done when the gasket surface is evenly sanded all around. If you really want to see what is going on, evenly "paint" the surface with a permanent ink felt pen in between each 90 degree rotation. The ink will get removed only on the high spots first, then when it is getting removed evenly all around you are done.
Thoroughly wash all parts with HOT soapy water to remove all traces of metal dust before re-assembling.