Alright so I acquired a 2 stroke MB from from a friend and no nothing about it. I have ridden it a bit (for like two months haha). The motor seems to run well but the chain recently (yesterday) snapped so i gotta replace that. Prollygonna run a 410. My main question would be how to identify the brand And size of the motor on it i.e. 49cc 66cc etc. It has two chinese symbols on the side of the carberatour if that helps anything lol. Next would be what basic things should i do to the motor for a "tune-up." I have been reading this sitre since i got the bike and am exctided to become a part of this internet community of sort. :
Questions questions questions!! Heelllppp!
- Thread starter bassplyr101
- Start date
Determining brand and manufacturer will be essentially impossible. These engines are manufactured by several factories in China and assembled and sold by small mom & pop companies under various brand names. Some distributors also name them with their own logos and/or stickers. To be absolutely certain of the displacement you'll need to remove the cylinder head and measure the bore and stroke. An easier way and usually accurate is to check the cylinder stud diameter. Typically the smaller, 49cc engines will use a 6mm stud whereas the larger engines have 8mm studs. If you have the chrome acorn nuts on the cylinder head, the larger engines will require a 14mm socket. I'm not sure about the smaller engine nut size.
The NT designation tells you that you have a good carburetor. The NT is the simplest and easiest to tune over several others available.
As for "tune ups" There isn't much to do to a 2 stroke engine. Keep the fuel clean by using a good in-line fuel filter betwen the tank and carb and run good quality 2 stroke oil formulated for air cooled engines at a ratio of 32:1. Keep the air filter element clean and occasionally open the right side gear cover and apply just a dab of grease to the gear teeth. Go easy here, don't use too much grease. On the other side is the clutch actuator. There are three moving parts that require periodic lubrication. The cam inside the cover, there is a pin which protrudes from the center of the drive sprocket and a ball bearing that is behind that pin.
Other than that just the normal bicycle maintenance is required; wheel bearings, chain lube and maintain your brakes.
Have fun, ride safe.
Tom
The NT designation tells you that you have a good carburetor. The NT is the simplest and easiest to tune over several others available.
As for "tune ups" There isn't much to do to a 2 stroke engine. Keep the fuel clean by using a good in-line fuel filter betwen the tank and carb and run good quality 2 stroke oil formulated for air cooled engines at a ratio of 32:1. Keep the air filter element clean and occasionally open the right side gear cover and apply just a dab of grease to the gear teeth. Go easy here, don't use too much grease. On the other side is the clutch actuator. There are three moving parts that require periodic lubrication. The cam inside the cover, there is a pin which protrudes from the center of the drive sprocket and a ball bearing that is behind that pin.
Other than that just the normal bicycle maintenance is required; wheel bearings, chain lube and maintain your brakes.
Have fun, ride safe.
Tom
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Thank you much ill have to check next time im around a wrench set. Also how would i go about making sure my alignment is true from the engine sprocket to the rear? Just eye ball it??
If your chain is giving you no problems it's a good bet your alignment is okay. Keep the tension at 1/2 to 3/4" slack.
A chain that is not aligned properly will usually jump off the sprockets. If you're not seeing that you should be good to go.
Tom
A chain that is not aligned properly will usually jump off the sprockets. If you're not seeing that you should be good to go.
Tom
The chain has repeatedly broken on me and actually violently snapped and exploded just yesterday haha
We usually recommend replacing the kit supplied chain with a good industrial #41 chain. It's available at most any industrial supplier, Grainer, Tractor Supply and even many Ace hardware stores carry #41.
To answer your original question, yes, you can eye ball it as long as you have a good feel for what straight is. Sight down the chain run from the rear of the bike looking forward. You should be able to see if the engine drive sprocket and the rear wheel sprocket at aligned. If you're using the kit supplied chain tensioner check the alignment of the wheel of the tensioner with the chain. Almost without exception the bracket will require a slight twist to get the tensioner wheel to align.
Tom
To answer your original question, yes, you can eye ball it as long as you have a good feel for what straight is. Sight down the chain run from the rear of the bike looking forward. You should be able to see if the engine drive sprocket and the rear wheel sprocket at aligned. If you're using the kit supplied chain tensioner check the alignment of the wheel of the tensioner with the chain. Almost without exception the bracket will require a slight twist to get the tensioner wheel to align.
Tom
