I bought a virtually new bike

GoldenMotor.com
Aug 21, 2010
37
2
8
Kingman AZ
I hope I didn't act too hasty but what the heck, it's only $175. A guy bought 2 of them for $350 each. One for him and one for his wife. When she saw what he did he got "the look". Needless to say she was NOT riding with him. Sooooo up for sale at half price. I will describe as best as I can what I have. Only downside is that they sat in his garage for 2 years so we WON'T use the gas. It ran for about 2 seconds with a new plug and I shut it right down. I'll put some 16:1 in it in a couple of days. Anyway, It's a Roadmaster Mt. Fury Mountain bike. The engine is by Skyhawk. It's a Starfire GT-2 48cc/1.95 HP. Made in 2009. The tires are 26/1.95 INNOVA.
I'm glad it's a 48cc since that is the max under AZ law. It's been said that the cops have no way of knowing. Well that's true if the cop CAN'T read. It's on the engine plate. As just a bike it seems to ride "kinda fair" and I found out something very interesting. You can lock the clutch out so you don't have to hold it in when you just cycle w/o the engine running. I have NO book for this sooo I will search the "information highway" and hope to find one. I already broke one brake lever and split the lead button from the other brake. So I rigged one front brake and will buy what I need when I go to town for 2 cycle oil and some gas. (We live rural).
Anyway, this is my first bike so it's a learning experience. If all goes well I look forward to getting a little trailer to haul some light but bulky stuff into the boondocks for prospecting. Any advice or suggestions please let me know before I break anything else.
 

dirt

New Member
Aug 13, 2011
54
0
0
United States
Pictures would be nice. I have basically the same set up. Mine is a Roadmaster, but I think a bit older with a 48cc slant head Skyhawk. You can download the manual from Gasbike.net Typical advise for this. Replace the sparkplug, sparkplug wire, mounting bolts and chain to say the least. Bolt torque is 10 foot pounds for head bolts and mounting studs. Check the torque on everything before each ride or after the engine has cooled down. Use blue Loctite. Be careful of the head bolts. They can come loose after a long ride and blow the head gasket. Get mirrors. Visit Sick Bike Parts web site. After drooling, buy some stuff. A lot of parts are inexpensive and they have all been of top quality for me so far. Mine has their HD shift kit and where I live it was the difference of having a usable bike or not. I've also installed their sound dampeners which have helped.

Don't ride with just a front brake. I'm looking at upgrading both my wheels for improved brakes and axle bearings.

Sturmey Archer

PERMACO - Bicycle Accessories & Parts

26" FRONT WHEEL WITH DRUM BRAKE HUB: Husky Bicycles




 
Aug 21, 2010
37
2
8
Kingman AZ
don't forget to tell him NOT to follow the oil ratios in the instructions.
First off, I could not locate the manual to download. Second, the web site says 16:1 to 20:1 for the first 4 tankfuls. After that about 25:1. What is recommended by those that do this a LOT? Also, replacing a lot of stuff is daunting. Mounting bolts (what size?) As for chain, what part number am I looking for? It sounds like I'm replacing half the bike. I'll check the web sites I was given by dirt and see what I can come up with. Thanks.
 

decoherence

New Member
Aug 23, 2010
476
2
0
sebring,fl
first you need to know what kind of oil you want to use before you pick a ratio.
those things are like a religion. every body has an opinion.

@ the top, use the search box.
it is a custom google that searches just these forums.

search for.
"what oil"
"bolt size"
"chain size"
i already pre checked those search terms to make sure they are help full.
even better than finding the answer is finding the "why" of the answer.
 

dirt

New Member
Aug 13, 2011
54
0
0
United States
First off, I could not locate the manual to download. Second, the web site says 16:1 to 20:1 for the first 4 tankfuls. After that about 25:1. What is recommended by those that do this a LOT? Also, replacing a lot of stuff is daunting. Mounting bolts (what size?) As for chain, what part number am I looking for? It sounds like I'm replacing half the bike. I'll check the web sites I was given by dirt and see what I can come up with. Thanks.
I did replace half the bike. Let's see so far I've:

  • Replaced the rear freewheel after the old one locked up.
  • Replaced the rear derailleur after the old one locked up.
  • Replaced the seat after my bu** locked up.
  • Replaced the handle bars with taller ones after my back locked up.
  • Replaced the cranks so I could add a shift kit.
  • Replaced all the chains.
  • Replaced the pedals.
  • Replaced the grips.
  • Replaced all the cables.
  • Replaced all the motor mounting bolts.
  • Replaced all the motor cover bolts.
  • Tuned the carb.
  • Added a SBP shift kit.
  • Added a SBP fuel filter.
  • Added SBP sound dampeners.
  • Added a head light and tail light.
  • Added mirrors.
  • Added a rear rack and cargo bags.
  • Added a speedometer.


I still need to replace the tires and tubes as well as upgrade the axles and brakes. This isn't mentioning the endless tweaking that I've done with it to get everything working decently.

Do some searching for oil ratios on the forum. Everyone has their own opinion, but the manual's ratio is using 30w motor oil. Do some reading and decide for yourself what you want to do. If you use store bought mix (which most new people do) it is different. Personally I just buy Ace hardware brand mix and broke my engine in on one 8oz bottle of mix per gallon of gas. Then I went to 4oz of mix per gallon. So far so good. I guess time will tell if I made a good choice or not.

Sick Bike Parts (SBP) has good chain on their web site and it is pretty inexpensive. If you do not have a shift kit then it is more important to replace the motor chain than the pedal chain. The chain that comes with the kit is pretty much junk.

The best way to make sure you get the correct size bolts is to take the old ones with you to the hardware store. That is what I did.
 

dirt

New Member
Aug 13, 2011
54
0
0
United States
Oh ya, I also replaced the spark plug and plug wire. I'm sure that there is more that I am forgetting but you get the point. The thing to remember is that I have really enjoyed doing all of this. It is great fun to tinker with and even more fun when you get it working right and you can ride it. You do a lot of this :-|| then you do a lot of this dance1 . Last but not least comes the best part cvlt1
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
26
36
Indianapolis
First off, I could not locate the manual to download. Second, the web site says 16:1 to 20:1 for the first 4 tankfuls. After that about 25:1. What is recommended by those that do this a LOT? Also, replacing a lot of stuff is daunting. Mounting bolts (what size?) As for chain, what part number am I looking for? It sounds like I'm replacing half the bike. I'll check the web sites I was given by dirt and see what I can come up with. Thanks.
Re the oil: he's right about letting the oil you use help decide the ratio. I can't recall the brand I used to use, but I remember starting at 16:1 and having nothing but trouble, even after futzing with the carb settings. If you're really fouling plugs and black stuff is dripping out the tailpipe, cut back to 20:1. Still doing the same? - 32:1. At about 32:1 mine started running smoother and stopped fouling the plug. And there was still some getting back into the carb, and I could still feel good viscosity with my fingers, so I knew she was getting plenty lubed all the way around. Later, after break-in was up, I went to 40:1.

If you know what to look for, the oil you use can help you decide ratio.
 
Last edited:
Aug 21, 2010
37
2
8
Kingman AZ
Dirt, you ROCK!!! Got it downloaded AND printed for reference. The oil is still a bit hazy but it looks like I will go with 24:1 for break in and 32:1 after. This is only to relax my brain from worrying for now. Since I can't get to town for a couple of days I won't be riding it with the engine running. One thing that also stops my progress is the lack of local support. There seems to be NO ONE local that shares this passion. The same with my Baja Bug. I'm kinda on my own as far as hanging around with other affectionados that stand ready to help with projects and advice in real time. As for buying stuff. We have a couple of MC shops here and quads are plentiful albeit 4 cycle. I think the Harley shop can help. We have a bicycle shop but I don't know their attitude to MB's yet.
I have to say right up front that this bike will in no way be a "daily driver". If it's down for parts or something I still have a F-150, Baja Bug and a Rodeo. With that being said I still will have a specific USE for it but not a specific NEED. My planned use will be mostly on flat level roads so the motor will be a luxury since I CAN peddle myself home. I want to know all I can about this because I don't mind something not working BUT not because I screwed up. It looks like there is a "pre-trip" check list that makes sense. If I get into the habit of going through it every time I want to ride things will go a lot smoother. As things stand now the absolute furthest distance from home I will take is 40 miles . I can peddle home if I must.
I thank everyone for their kind attention to my needs and questions. I will still be asking BUT I will also try myself to find the answers. The last thing I am looking into is the chain. The manual talks about a 415 chain. Without being in my garage I will for now think that this is what I have. I will search for an upgrade and get back with a progress report. Thank you again.
 

dirt

New Member
Aug 13, 2011
54
0
0
United States
I'm all on my own too, as far as local support. I'm used to it though having rebuilt a '55 Jeep from the frame up with basically nothing but internet help. This forum really is a great place for help and support though. I try to stay with bicycle parts as much as possible/safe. This is just so I can easily get replacement parts in town if I have to. I live out side of town as well. It's a small town of about 3,000 people, but I can still buy things like chain, pedals, cables, Loctite, oil and hardware there if needed. Someone can correct me on this, but if I remember correctly I think that 410, 415, BMX or #41 roller chain will work for the motor chain. You can run the old stuff for as long it holds up. It just stretches really fast. It only lasted a few trips for me.
 

Fulltimer

New Member
Aug 13, 2010
1,321
3
0
77
Saint Augustine, FL
I think everyone would agree NOT to use regular automobile motor oil in your gas. There are regular 2 cycle oils that works great and then there are synthetic 2 cycle oils that also work great.

Terry
 
Aug 21, 2010
37
2
8
Kingman AZ
New question. My torque wrench does not go down to 10 ft lbs. So I have an inch pounds wrench which will go down. I "believe" 120 inch pounds is 10 ft lbs. As for mounting bolts. After a quick look at the bike there seems to be NO bolts on the front (at least that I can see without lying under the bike) and the bolts in the back are studs. I can take the nuts off (10MM). Is it recommended to take a vice grip and remove the old studs and replace with something stronger? I have seen posts where they have sheared and broke even with the block making it necessary to drill the old broken one out. I think a lot sticking out now is better than nothing sticking out later. I believe someone recommended the replacement of the head bolts. Are these studs as well? If so it looks like I must remove the head to accomplish this. Once again, thank you for your help.
 

decoherence

New Member
Aug 23, 2010
476
2
0
sebring,fl
there is 4 mounting studs. 2 on the back. 2 in a bottom/forward position.
replacing them is a good idea. many of us re tap them for bigger studs.
your calculation is correct. i double checked w/ google.
if you put in part of an equation or a conversion. it will give you an answer that isn't a website.
if you can get the studs off w/vice grips go ahead.
a better way is using 2 nuts. put them both on the stud. tighten them together. then unscrew with the nut that is closer to the engine.

i haven't the need to touch my head bolts yet. i imagine i will need to one day. so you can either do it now or later.
 
Aug 21, 2010
37
2
8
Kingman AZ
It gets better. The reason that I DON'T have mounting bolts on the front is because the diameter of the frame at that point is wider than the bolt pattern for mounting. My first thought is to take my Dremel and cut a channel for the bolts to clear. I don't know if this will weaken the frame to any great extent. The good (if there is one) is that the front mounting "area" sits on the frame and looks secure. Since the torque will pull down on the front it looks like it can only seat itself tighter on the frame. I could "rig" something to keep it from dropping down in time by perhaps wearing on the aluminum block itself. I am wanting to change the spark plug wire as advised but it seems to be permanently secured into the "kill switch" assembly. I wonder if I pull hard enough if I cannot make it come out and put another one.(there is NOTHING that brute force and ignorance cannot overcome). It is now stretched as far as it will go. If I can find a "stubby" spark plug it will not have to go quite as high. I am also planning on going with a dual brake lever. I found that "super strong" chain for $60. I went through the pre-trip procedure so all the tools that I will need are together in one place.
Good thing that I'm retired and have the time to do all the stuff I want to. I could NEVER do my old job (long haul truck) and do this also. Thank you again for your help.
 

decoherence

New Member
Aug 23, 2010
476
2
0
sebring,fl
i definitely would not cut channels in the frame.
either buy of make something like this.
Sick Bike Parts

if you are talking about pulling your sparkplug wire from the cdi, it unscrews counter clockwise. if it is stuck, there might be glue holding it. try digging @ the glue & unscrewing it..

i personally would not use a duel brake pull for both brakes.
more change of both tires locking up. the tires won't track if they are both locked up. then you could go sideways.

think about how a car always always has more front stopping power than the rear. the rears can still roll to "rudder" so the car will more likely go straight.
 

dirt

New Member
Aug 13, 2011
54
0
0
United States
I agree with the above. Do not cut the frame. I wish I had went with the SBP adapter for my fat front tube, but the one that I came up with works. It is just not as nice looking. Perhaps some day I will replace it.



My old spark plug wire was a bear to get off. It basically ripped off and then I dug out the old insulation from around the screw. The new plug wire from SBP is quite a bit longer than the original one.

I used bolts instead of studs for the engine mounting, the carb manifold mounting and the exhaust mounting. Don't forget the Loctite.

Another thing you may want to do is replace the "plug" connectors on the CDI. I wire nutted mine and put electrical tape around them. I think that soldered would be even better, but I haven't had any trouble with it yet.
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
26
36
Indianapolis
I love the SBP large-frame motor mount adapters! They're friggin' awesome. They're so solid you could almost use 'em on a truck! If you do buy one from them, you will NOT be sorry.
 
Aug 21, 2010
37
2
8
Kingman AZ
While it's on my mind. Is there a stubby plug for that engine (GT-2)? What is one that anyone could reccommend if there is not a stubby? It came with a LD Z4C . The instruction manual that I downloaded mentions a M4X1.25. I got the plug wire off but don't know how to order a new one. Do I have to specify the length of the wire or is it a standard length? As I looked at the plug before I removed it there was a slight gap between the washer and where it would normally sit up on the plug. When I went to put it back the washer squeezed onto the area above the threads and the plug seated a slight bit deeper than it had. I want to make sure that I have the right plug for 2 reasons. I have seen plugs that have more thread length will do 2 things. Perhaps hit the top of the piston (NOT good). Second, they will carbon up on any threads sticking into the cylinder to the point of filling up the area between the threads. When this happens you can EASILY rip out all of the threads in an aluminum head while removing it.
As for the add-on motor mount. It looks like I will have to at least loosen the motor so as to lift it up and put the bolts up and into the holes where they would fit if I had a thinner frame. Then clamp the new mount to the frame.
The more I see that I "should" do the more I want to just treat it gently for now and then make it a "winter project" where I can do it all at my liesure. It's good for now BUT it will be better later. Thank you again.
 

dirt

New Member
Aug 13, 2011
54
0
0
United States
I used this plug:
Sick Bike Parts NGK B5HS

and this wire:
Sick Bike Parts High Performance Plug Wire

You have to change the wire when you change the plug though. The old wire does not work with the new plug and vise-versa. Just order them both at the same time. The new plug wire is extra long and you just cut it to length.

I simply measured the length of the plugs from the tip of the electrode to the shoulder of the threads to make sure they were the same length, and they were. I would feel pretty safe in saying that this plug isn't too long, but ultimately it is your responsibility to make sure that it won't hit the piston. Be sure to gap it.

It is a really bad thing to run the motor with a loose spark plug. Chances are that it was vibrating loose (one of the items that should be in the pre-ride inspection).