A couple questions on first build

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Flight Risk

Flight Risk

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I have a Grubee 48cc and have the instaltion mostly finished.
First questionI have the clutch adjusted according to the directions and when the clutch is pulled all the way in, there is a lot of drag, and seems like it will be a pain to pedal.Will this loosen up after it is ridden a bit? I have searched the threads, and found out about a flower nut. Should that be adjusted on a fresh motor?
Also I am considering shorting the throttle and clutch cables, as they seem to bind a bit no matter how I try to route them.
Other than that, I think I can gas it up.

thx

Rod S
dance1
 
2door

2door

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Sep 15, 2008
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Listen to Bairdco. There is no need to mess with the clutch adjustment at this stage. If the clutch cable is adjusted correctly you should be able to spin the rear wheel. As things begin to wear in pedaling with the clutch disengaged will get a little easier but don't expect it to feel like it did without an engine. There will always be resistance from the rotating parts of the engine along with the chain, sprockets and tensioner. Shortening the clutch and throttle cables will not lessen the binding and could make it worse if it makes them too tight. Make sure you have no tight bends or kinks in the cables and they will benefit from some lubrication. A light oil, some use graphite, on the cable before it is inserted into the housing will reduce the amount of pressure needed to pull them. Let us know how things go.
Tom
 
Flight Risk

Flight Risk

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Thanks guys for the replies.
I've tightened up the clutch some more, and actually fired it up and drove a few blocks in our 30 degree weather. I need to work on the tuning. The engine was running fine till I think it got too cold and I had to turn on the choke again. I got a good workout trying to keep it going. I'll be lubing the cables tonight.

Rod
 
Flight Risk

Flight Risk

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Update and a new question.
I have probably 20 miles on the bike in the last couple days, and it is generally running good. In the previous post you notice it was running poorly, so the next day I adjusted the air/fuel mixture screw and it has been running fine since.
But my idle was high and I was at the end of the cable adjustments. So I took the carb off and filed down the top of the carb about 1/8" so I have more adjustment. But the idle stayed the same and I noticed there was actually a bit of slop in the cable. So then thought that something was hanging up the carb piston and preventing it from closing. So I checked the forum and found that air leaks are a common problem. But i found no air leaks, so came back to check the forum and found that there is an idle screw somewhere.
Finally I discover that the air/fuel mixture screw is actually the idle screw. It now idles nicely. but where is the mixture screw as mentionrd in the instructions?
My guess is there is no mixture screw. Is the only way to change the mixture by adjusting the jet needle? Strange.
My next project is to get a larger sprocket since I'm in a hilly area and currently need to do a lot of pedalling as this 48cc is guttless (should have gotten the 66). Also I would like to go on some trails, but first gear (only gear) is quite fast. Also am thinking a centrifugal clutch would be nicer, as I find myself rolling through intersections so that I don't need to stop and then slip the clutch while pedalling. Is slipping the clutch bad?
If you read through this entire post, thank you.


Rod S
 
2door

2door

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Sep 15, 2008
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Flight,
Not quite clear on what you filed down on the carburetor. It wasn't the threaded section where the cable attaches to the carb, was it? If so, that's why you now have some slop in the cable.
You have already discovered that there is no mixture screw. The only external adjustment is the idle sped screw which simply blocks the carb slide from going lower when screwed in, therefore setting idle speed. The mixture can be adjusted by raising or lowering the small 'C' clip (some call it an 'E' clip) on the end of the needle valve. The second slot from the top is a good starting point. Lowering the clip will richen the mix, raising it will lean the mix out. Don't expect dramatic results from this however.
What rear sprocket are you using now? A 41 to a 44 is a good all round size. Moving up to a 48 or larger will give you better hill climbing ability but will hurt your top end speed and raise engine rpm on the flats. Slipping the clutch on a bike will induce wear on the clutch friction pads just as it would in a manual transmission automobile. Instead of slipping the clutch most of us rely on a little pedalling help on starts especially on an uphill start. There's no shame in using your pedals. Disengage the clutch completely, pedal up to speed then release the clutch and go. It's not a motorcycle.
Tom
 
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Flight Risk

Flight Risk

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Thanks for the pointers Tom. Since figuring out that the instructions were wrong/misleading about the mixture screw, the carb issue is resolved.
I have a 44 tooth now, and don't mind loosing a bit of speed. I'm at 6,000 feet so am not getting full power out of the engine. Maybe as it breaks in it will get better, but it seem to need a slight downhill to rev-out the motor. The slightest uphill and it seem to get 1/2-3/4 speed. I'm 220 lbs and the bike another 80 or so, so that's a lot of weight to carry.

RS
 
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