2019 TaoTao TBR7

[Viperbmw69]

Originally Posted by culcune

You may or may not need to deal with the carb initially; have you done the valves?

No but I did by a new mikuni carb and jets they are in the mail. I will try that and see what it does. What jet size should I use I live at about 3k elevation

[NzBrakelathes]

I’m looking into a kit to tidy up these locked out USA version carbs
Sub $20 fix and all you’ll need parts n tool wise
Stay tuned as Chinese New Years has arrived n no one is shipping etc
Got pretty much the main stuff coming by the end of week n I’ll see if I have it right or egg on my face

[Ariel Red Hunter]

Originally Posted by NzBrakelathes

I’m looking into a kit to tidy up these locked out USA version carbs
Sub $20 fix and all you’ll need parts n tool wise
Stay tuned as Chinese New Years has arrived n no one is shipping etc
Got pretty much the main stuff coming by the end of week n I’ll see if I have it right or egg on my face

I think that's a great idea, with one potential problem. Jets. There's gotta be somebody in China who makes, or can make accurate Mikuni jets. Mikuni flow tests every jet they make before they mark them, or one in ten. Or they have developed a computer program that tells them how many of each jet they can make before they go out of spec by testing actual flow. That's why they cost more...ARH

[Ariel Red Hunter]

Originally Posted by Viperbmw69

No but I did by a new mikuni carb and jets they are in the mail. I will try that and see what it does. What jet size should I use I live at about 3k elevation

I believe these carbs come with a 95 main jet. That should work, but if it is still too lean, try a 100. I hope you bought genuine Mikuni jets. They are the only ones that I know of that are actually flow tested to make sure they are the size they say they are...ARH

[Megadan]

Originally Posted by Viperbmw69

No but I did by a new mikuni carb and jets they are in the mail. I will try that and see what it does. What jet size should I use I live at about 3k elevation

So, the No is to the valve adjustment question he asked? If not, then I would recommend adjusting the valves before doing anything else.

[Viperbmw69]

Originally Posted by Megadan

So, the No is to the valve adjustment question he asked? If not, then I would recommend adjusting the valves before doing anything else.

I tried adjusting the valves and I am not sure I am at tdc. I see two lines then an f and line then like a oval and small line and long line. When I adjusted the values they were very very tight and I had to move them up a lot to get them to free up enough to realine the set but. I assume this was way wrong. I used the oval and assumed it was the t and a manufacturer defect. Used .007 on both. When I was done the bike starts and has a very loud clicking sound of the values. I opened and again and tried the same way at .003 on both. Still loud clicking..

[512customs]

Originally Posted by Viperbmw69

I tried adjusting the valves and I am not sure I am at tdc. I see two lines then an f and line then like a oval and small line and long line. When I adjusted the values they were very very tight and I had to move them up a lot to get them to free up enough to realine the set but. I assume this was way wrong. I used the oval and assumed it was the t and a manufacturer defect. Used .007 on both. When I was done the bike starts and has a very loud clicking sound of the values. I opened and again and tried the same way at .003 on both. Still loud clicking..

If your having a hard time seeing the flywheel timing marks, take the spark plug out and use a pencil or something similar to verify piston is all the way to the top of its stroke.

[Viperbmw69]

Originally Posted by 512customs

If your having a hard time seeing the flywheel timing marks, take the spark plug out and use a pencil or something similar to verify piston is all the way to the top of its stroke.

Can you explain that a bit more? How do I know if it's at the top? What's the pencil for?

[paulsstag]

Originally Posted by Viperbmw69

Can you explain that a bit more? How do I know if it's at the top? What's the pencil for?

I hope i can help with the explanations to what everyone is saying. First off the pencil or screwdriver or chopstick or straight piece of wire is put down the spark plug hole so that you can feel the top of the piston, so when you rotate the engine you should feel the piston move up and down. This is a very crude way of confirming top dead center or TDC.

Next : with these being 4 stroke engines the crankshaft and piston assembly makes 2 full revolutions and the camshaft ( controlling the valves ) makes one revolution, so the camshaft is geared to turn at half the revs per minute (rpm ). It therefore takes 2 revolutions to make the complete the 4 strokes needed for a complete cycle.

With this being said the piston gets to TDC twice to complete this cycle At the TDC of one of the cycles both valves are closed briefly so that the piston does not hit them , the exhast valve is closing and the intake valve is about to open. If you set the valves at this TDC then the valves will usually be very loose. The next TDC is when both valves have been closed for a longer period of time so that the air in the cylinder can be compressed and ignited by the spark plug . It is at this TDC that you should set the valves.

If you watch the valve action while turning the engine you will see a time when the exhast valve is closing and almost immediately the intake valve starts to open ( don't set the valves here ) When the intake valve finishes closing then the piston is about to head back up to TDC, When it reaches TDC this is the time to set the valves. As a confirmation you can put your thumb or finger over the spark plug hole and actually feel the air in the cylinder getting compressed.

I hope this helps.

[Viperbmw69]

Originally Posted by paulsstag

I hope i can help with the explanations to what everyone is saying. First off the pencil or screwdriver or chopstick or straight piece of wire is put down the spark plug hole so that you can feel the top of the piston, so when you rotate the engine you should feel the piston move up and down. This is a very crude way of confirming top dead center or TDC.

Next : with these being 4 stroke engines the crankshaft and piston assembly makes 2 full revolutions and the camshaft ( controlling the valves ) makes one revolution, so the camshaft is geared to turn at half the revs per minute (rpm ). It therefore takes 2 revolutions to make the complete the 4 strokes needed for a complete cycle.

With this being said the piston gets to TDC twice to complete this cycle At the TDC of one of the cycles both valves are closed briefly so that the piston does not hit them , the exhast valve is closing and the intake valve is about to open. If you set the valves at this TDC then the valves will usually be very loose. The next TDC is when both valves have been closed for a longer period of time so that the air in the cylinder can be compressed and ignited by the spark plug . It is at this TDC that you should set the valves.

If you watch the valve action while turning the engine you will see a time when the exhast valve is closing and almost immediately the intake valve starts to open ( don't set the valves here ) When the intake valve finishes closing then the piston is about to head back up to TDC, When it reaches TDC this is the time to set the valves. As a confirmation you can put your thumb or finger over the spark plug hole and actually feel the air in the cylinder getting compressed.

I hope this helps.

Wow now that is an awesome detailed post. Thank you very much for this. I will give this a shot in the morning. Sorry for being a bit of a noob but I want to make sure I do the right thing. Thanks so much!!!!

[paulsstag]

Originally Posted by Viperbmw69

Wow now that is an awesome detailed post. Thank you very much for this. I will give this a shot in the morning. Sorry for being a bit of a noob but I want to make sure I do the right thing. Thanks so much!!!!

It is my pleasure. Although setting the valves is a very good thing to do and check occasionally i do believe from your description of the way the bike runs plus the many posts on this forum your bike sounds like a textbook case of running too lean. Try to get a bigger jet in your stock carb and put a spacer under the needle to lift it up relative to the jet and emulsion tube it is sitting in (this makes the 1/3 ro 3/4 throttle position a little richer or fit the aftermarket one and start with a 105 jet and the needle clip in the center position adjust to suit.

[Ascot500]

Setting the valves need not be that complicated
If one valve is completely opened, then the other has to be completely closed
So turn the crank until you see one valve being pushed all the way down and then adjust the other valve

[NzBrakelathes]

I sell a tool set with gaskets for the job and I believe it’s a worthy product to have in your tool set
Self plug yeah ok but take a look n decide your self

https://rover.ebay.com/rover/0/0/0?m...2F303052643011

[Megadan]

Originally Posted by Ascot500

Setting the valves need not be that complicated
If one valve is completely opened, then the other has to be completely closed
So turn the crank until you see one valve being pushed all the way down and then adjust the other valve

While it can be done this way, the reason TDC on the compression stroke is the standard method has to do with the fact that the statement of "while one is open the other is closed" is not always true. In particular, just before, during, and after TDC on the exhaust stroke, both valves will be actuated to some degree due to lobe overlap. This is the common mistaken TDC some people set their valves to. Since the clearances are so small to begin with if the follower is even slightly touching an area other than the base diameter of the cam profile, the tolerance set at the valve will be off.

This is why I keep it even simpler and just say to watch for the intake valve to open, and then the next TDC mark on the flywheel will be TDC on the compression stroke.

[Ariel Red Hunter]

Originally Posted by paulsstag

I hope i can help with the explanations to what everyone is saying. First off the pencil or screwdriver or chopstick or straight piece of wire is put down the spark plug hole so that you can feel the top of the piston, so when you rotate the engine you should feel the piston move up and down. This is a very crude way of confirming top dead center or TDC.

Next : with these being 4 stroke engines the crankshaft and piston assembly makes 2 full revolutions and the camshaft ( controlling the valves ) makes one revolution, so the camshaft is geared to turn at half the revs per minute (rpm ). It therefore takes 2 revolutions to make the complete the 4 strokes needed for a complete cycle.

With this being said the piston gets to TDC twice to complete this cycle At the TDC of one of the cycles both valves are closed briefly so that the piston does not hit them , the exhast valve is closing and the intake valve is about to open. If you set the valves at this TDC then the valves will usually be very loose. The next TDC is when both valves have been closed for a longer period of time so that the air in the cylinder can be compressed and ignited by the spark plug . It is at this TDC that you should set the valves.

If you watch the valve action while turning the engine you will see a time when the exhast valve is closing and almost immediately the intake valve starts to open ( don't set the valves here ) When the intake valve finishes closing then the piston is about to head back up to TDC, When it reaches TDC this is the time to set the valves. As a confirmation you can put your thumb or finger over the spark plug hole and actually feel the air in the cylinder getting compressed.

I hope this helps.

Very good explanation, except for the sneer about finding TDC with a chopstick or a straw, the way it has been done for - oh - 110 years or so. Super sophisticated methods of finding top dead center are not neccessary for valve adjustment. All you really need is to be around TDC on the compression stroke/power stroke. Why? Think about it. You aren't going to get any compression worth talking about if one or more valves are open on the compression stroke are you? And what kind of power are you going to get if one or more valves are open after the spark plug fires on ye power stroke, right? So, the simple, time honored way to do this is to jiggle a chopstick, or whatever, in the spark plug hole to feel where the piston is. Pull it back up, or out and advance the engine a little with your hand on the kickstarter. Check it again, and repeat until most of the stick is out of the cylinder. Now put the stick back in the spark plug hole and very slowly, using the kickstarter, watch the stick rise until it stops rising. If you keep going, the stick will stay up at the same height and then just start down. Half way between from where it stops coming up and starts going down is utterly and absolutley TDC. This is called TDC "dwell". Anywhere in the TDC dwell area is where one sets the valves. On the compression stroke, remember. How do I know when I'm on the compression stroke? Well, you put your finger over the spark plug hole and.....Jeez, do I gotta' tell you everything??? ARH