can't find an answer then ask here someone may be able to help!!

[GearNut]

Randog707, follow sligo rider's suggestion. It sounds like you either have a bad air leak or the throttle slide is installed backwards in the carburetor, or for some reason or another the slide will not go all the way down into the carburetor like it should. It even could be a sticking throttle cable or throttle grip. Are there any sharp bends or kinks in the cable routing along the frame?
Remove your air cleaner and look down the throat of the carburetor using a mirror if necessary. Watch the slide move up and down while you work the throttle grip. The slide should move smoothly and be barely above the floor of the carburetor throat when you release the throttle grip. If it is 1/8" or 2mm above the floor that is too much and will cause the high idle and 10mph "cruise control" you are describing.

 

[kenkon]

I'm sorry to ask, but I've run out of options. I just finished installing a grubee 58cc(yes 58cc) starfire GEN-2 motor kit. I had it running for about 20 minutes then my back tire locked up and the engine refused to fire. After examining it, it seems the clutch plate moves but the gears inside do not. When the clucth is engaged I can still pedal but everything seems to be moving very roughly. I checked the chain, its clear, chain tensioner is ok, electrical is fine, etc.. but the gears don't move when the clutch is out and I'm turning my rear wheel. Someone please help me!

 

[Norman]

So will your engine crank? I wonder if you sheared a key on one of the gears or the front gears locking screw backed off or broke?
Take off the covers all of them take a hard look at all moving parts see what will move or may be binding. some photos would be nice as it may help us figure out whats wrong.

 

[kenkon]

Nothing happens when I try to turn the engine over manually,(clutch released, rotate tire or by using adapter designed for feeding chain through sprocket). The clutch plate rotates but the gears don't even move. I tried re-calibrating the flower nut but no matter how loose or tight it is, the plate just rotates. The clutch plate is free, moves in n out freely w/clutch arm. It's 11 pm where I am, so I'll send pics tomorrow. Thanks for the prompt response!

 

[Norman]

From what your describing it make me think that the key on the clutch shaft has sheared or it missing.
You will need to remove the clutch completely. You will need lock the big and small gear with a rag jammed in between them so you can unscrew the clutch nut. Then use the puller tool to remove the clutch. (I hope your kit came with the clutch tool) before you use it clean and grease it, better yet use antisieze on the threads of the tool.
All nuts bolts on the engine are right hand so it's easy to unscrew any bolt or nut on the engine.
Once the clutch assembly is off you should find out whether or not that key is sheared or missing.
photo of the gear puller on the clutch you won't need to pull the engine gear like I have in this photo.( need to click on the link)
http://motorbicycling.com/attachmen...bicycle-engine-tear-down-totalteardown005.jpg

 

[deathmonkeypoo]

Ok i have replaced the plug and boot this morning and it only got me a few miles with me playing with the choke and I can only give it half gas. Im thinking its a vacuum in the tank or some thing stupid like that. Oh and does any one else have a problem with there choke rising To on bc of vibration from the motor and if so what did you do?

 

[Norman]

The choke can be stopped from vibrating to the on choke position by tightening the choke shaft bolt on the choke. It only needs a very light tightening.
Some people will put a rubber band on the lever to keep it from vibrating on.
I haven't had a tank that was liquid tight, although some people said their tank was. You can so a search on how to add a vent to the cap.
I really don't know just what your problem is with your engine. As your post don't really describe your problem. If your having trouble keeping the engine running with or with out the choke on then it could be your carb needs to be tuned, or you have a fuel flow problem. You also could have your spark plug gaped at 0.032 or more these engines in my opinion should be gaped less. I use 0.017 to 0.020.
If your not using a good paper filter on your fuel line it would be worth your while to get one. Almost all of the fuel tanks have rust and trash in them and even a very small particle of rust will stick the float needle valve either on or off. Which will either flood the engine or starve the engine for fuel.
So you have some cleaning, inspecting, and adjusting to do if your engine is not running properly.

 

[alltopafi]

Ok so I'm on my first build. I had the bike tuned nicely ran great Saturday evening. Took it to my hometown to show family on Easter ran great from my sisters to my aunts(less than mile) 3 or 4 people took test rides around the block shut it off visited with family for a few hours when I went to leave I couldn't get the engine to start I played with it a while took plug out which was pretty fouled up already(still had white spark) peddled bike with plug out, fuel off, and clutch engaged to blow any fuel that might have caused it to flood out went ahead and replaced with a ngk plug emptied the bowl on the carb. Still can't get it to start. Do you think I used to much oil in my mix I did 16:1 I was told to use that for first couple gallons I run through it. I'm pretty good with small engines, but this one is kind of beating me at the moment any ideas?
Thanks for the help,
Jesse

 

[Norman]

I use 0.017 to 0.020 for the spark plug gap.
Use a 32 to 1 for the fuel mix this is better than the 16 to 1.
You sure your getting fuel, did you run an inline fuel filter, when the kits are new there's trash in the tank and probably always will have trash in there so you got to run a filter in the fuel line. I like the paper fuel filter Walmart sells they work real good plus cheap.
Once the engine has ran say 1 to 2 tanks full switch to a syn 2 stroke oil. I use polan syn 2 stroke oil at 40 to1 mix, you can also get it a Walmart.
I should get a check from Wally for pushing their.....stuff?

Lastly while you had the float bowl off/or the drain plug out in the bowl, did you turn on the fuel to see if your getting fuel? These bikes fuel tanks will plug off through the tank valve/ strainer very easily.
If you got good spark at the right time,all you need is the fuel/air.
that made me think the choke can vibrate up choking it/killing the engine.

 

[alltopafi]

I do have a paper inline fuel filter, and the engine was getting wet. I have talked to a few people at the auto parts store I work at and they all seem to think I should use a lower oil gas mix as well so I'm going to drain the tank and carb and try with new fuel. As soon as I can I will let you know the results. Thanks again.

 

[alltopafi]

hows it going,
So my bike is running great now! Thanks again! My roommate ordered a 80cc kit from king motor bikes and we have it put together, when we couldn't get it started. At first it sounded like it wanted to start, but now when we let the clutch out there is no tension added at all do I just need to tighten the clutch plate.
Thanks yet again

 

[Norman]

Alltopafi
You now have your bike running? If so that is good news.
Your buddies bike is now having problems? With the clutch slipping? If you will read the post/stickys on the clutch you should be able to get it fixed.

 

[tonynorris]

norman,

first off, i wana say i think its great that you take time to help people out with these engines. now to the point, i bought a spark plug for the bike today, after i test drove it the thing wouldnt turn on the second time around. it doesnt have much compression anymore either. i tore the engine cylinder head off and inspected the needle bearing, gaskets, spark plug and the rings and it all seems fine. i put it all back together and torqued everything and still it wont start. the compression is also still ****ty. what do you think is the problem?

tony

 

[Norman]

You changed the spark plug rode it one time and now it won't start again? You said you also took it apart. first thing when they won't start is check for spark, fuel, timing. You said it don't have as much compression now?
Did you break a piston ring? putting it back together, is the head gasket leaking? or is your clutch slipping?
Did you get the proper reach spark plug and did you set the gap at 0.017 to 0.020 not the 0.035 or more?
there is a bunch of new worms you opened up by taking it apart,if your new to engines you might of did a NO! NO!.
Did by chance you get the ignition wires loose or wrong. The ol broke or shorted kill switch is one thing that a lot of people seem to have problems with, you might unhook the kill switch and try it if you run a kill switch.
Find out if you have spark first. Then if the engine is getting fuel. even low compression if it's getting spark at the right time and fuel should run.
You running 24 to 1 fuel mix or the 32 to 1 mix? I hope not the 16 to 1 that will fowl a spark plug very quickly.
there's a bunch to check and more info would help
You new to mechanics or experienced?

 

[tonynorris]

thanks for the reply norm! and ok, i found out that i have no spark, im going to order a new cdi tomoro, and yes all the gaskets were fine as so was the rings. i run 25 to 1 mixture, (every gallon gets round 5 ozs) and as for the clutch im not entirely sure how to check if its slipping. as for the spark plug, i gaped it at .037 or so. ihave some experience in engines, im more familiar with 4 and 8 cylinders tho. also, on a skyhawk 66 cc engine, can i run a 32 to 1 mix?

 

[Norman]

yea 32 to 1 is good. your running way too much spark plug gap. you need to check all wire connections and look for how to use the ohm meter on checking the magneto coil and cdi, those checks are on this forum some where.
these cdi's don't handle large spark plug gaps very well 0.017 to 0.020 is what I use and I don't ever have cdi problems. I have even rewound the magneto coils in the past they will break in the winding or at the wire that comes out of the coils center and is soldered to the magneto's frame often check the mag. coil for shorts or broken wires.

 

[this guy]

noman loved your carb teardown and rebuild very informative. you said the 'e' clip on the brass pin that seats into the main jet is set on the middle notch but when i lokked at mine it was on the top notch should i move the 'e' clip down and how. also now when i open the thrittle all the way my 48cc skyhawk motor seems to bog, but when i reduce to maybe 2/3 the way open i get the power bak and speed increases whats the deal> maybe you know thanks.

 

[Norman]

You can pop off the c-clip by pressing the clip off with the open end of the clip down towards the table, be gentle so you don't bend the needle ,you can pop it back on the same way except have the needle with the clip opening facing up in the groove you want it to go into.
It boggs at wot because I'm guessing your at or above 3000ft. you will need to rejet the main jet to one size smaller to 0.65mm stock is usually 0.70mm You will find the tools I use to do that in the stickys. micro drills and pin vice to hold the drill bits. Plain solder and a small propane torch to heat up the jet so you can solder it shut to redrill it a bic lighter will work it just takes a while to get it up to the proper heat.

 

[dryvway]

Hi, dryvway here and I have a skyhawk 66cc engine. I want to split the case and need to remove the small gear. I do not have the proper tools for this. Any suggestions?? I took it to a shop for this and they wanted to weld to the screw. Also, should I romove the cylinder studs and use anti-seize? And any other studs? Thanks for your time. Dryvway in Reno.

 

[Norman]

You will need to buy the gear puller if your engine kit didn't come with one. They are not expensive, I'm going to guess less than $10.00 not including shipping. Most all the vendors on this forum will or should have them you might even ask on swap and shop someone might have one for sale or even give away or trade.

The studs in my opinion are ok to use as long as you use the proper torque on them, the studs are not a high grade of steel and they are easily stripped if over tightened so a inch lb. torque wrench is a very good tool to get you can find these torque wrenches at cheap tool stores like Harbor freight, or buy a good one from Snap On or Sears etc.
Anti sieze should be ok for keeping the threaded aluminum from galling or sticking to the steel threads on the studs.
You might check and see if there's anyone in your area how also rides MB's they might be able to help you with taking the engine apart if your new to this kind of stuff.
Good luck.
Norman