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I’ve had this MT-A4 B1 rep for 3 weeks or so now and finally got to take it out last night. Drove out to a go kart track, running late, far away. Didn’t get much time but was a nice little taster. I’m going for a 4 hour session tomorrow.

The bikes looking real good in my opinion. I pushed the coolant reservoir out with a straight bracket and new hoses. This allows me to have the clip ons pretty much straight but still turn lock to lock both sides. A few R6 stickers here and there as I have a red n white R6 aswell for when the weather isn’t so bad lol.

The bike seemed to run well for about 2 laps, I was only on around 3/4 revs as I’ve still got to run in the bike but the powerband was kicking in nice. Then it just kind of started to bog and lose power. I pulled in, she didn’t sound as healthy and kept cutting out. I kept running it on the stand l, fiddling with the idle screw to try and get her nice. I did buy this ram air foam air filter and had laced it with air filter oil (as you do on mx bikes) and thought this is possibly starving the engine of air? So took it off for a minute and the bike seemed to be okay then. Eventually put the filter back on and she ran like a dream again. Got another 10-15 laps in. Still not full revving but the powerband felt good.

So far mod wise I’ve literally just swapped out the stock plug for an ngk b9egv I believe it was, as suggested in the manual. Replaced the tin reed petals for carbon ones and then swapping out the standard filter for that big foam ram air one. I bought a 72 tooth rear sprocket last night aswell after being recommended by one of the lads there. I’m currently waiting on an rpm gauge to set my clutch correctly and also a digital micrometer for setting the squish.

Anybody got any other suggestions for mods for speed, reliability, etc apart from a dellorto carb which is in the pipeline? Just want to make it as good as it can be really. The track I’ve took it to has a proper mini moto shop with all the spares and performance parts btw.

Another quick one aswell. At some point my choke lever stopped locking into place. I haven’t really needed to use it but I remember when I first got the bike, if you put the choke on, it would lock into the down position. You would have to push the lever to the one side for it to spring back up and turn the choke off. Now it won’t stay in the down/on position. It just springs straight back up. Any ideas? Ive tried to look to see how it works but I’m not quite sure.

Thanks everyone for all your information. Hope you like the bike 👍🏻
Have you had problems with the brake discs on your b1 rep not floating freely? I’ve tried adjusting them but they seem to rub no matter what
 

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Haven’t had an issue mate, if you can’t dial it out with the brake pad adjustment then maybe you have a warped disc?
It’s both the front and rear wheel mate, could try new discs but it’s brand new and hasn’t even been used yet and I’m fairly certain they aren’t warped, do your wheels spin freely if you spin them by hand? I know the back one is tighter as it’s spinning the clutch etc but even the front one will only spin 2/3 times freely
 

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Discussion Starter · #64 ·
It’s both the front and rear wheel mate, could try new discs but it’s brand new and hasn’t even been used yet and I’m fairly certain they aren’t warped, do your wheels spin freely if you spin them by hand? I know the back one is tighter as it’s spinning the clutch etc but even the front one will only spin 2/3 times freely
Doesn’t sound too uncommon mate. I’d take the wheels off, make sure the bearings are good, plenty of grease on them and the axle itself and then it’s trying to dial in the perfect balance. You want the wheel to spin as freely as it can whilst giving decent braking ability. I’d do the same with the rear but then you have the chain adjustment playing a part aswell. You’ll get used to it mate.
 

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Are you trying to use genuine B1 pads on a reproduction bike?

If this is the case then you may need to replace the rotors and calipers with genuine B1 parts as well a lot of times reproduction parts are close copies but not exact...
 

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Are you trying to use genuine B1 pads on a reproduction bike?

If this is the case then you may need to replace the rotors and calipers with genuine B1 parts as well a lot of times reproduction parts are close copies but not exact...
Hi mate nope it’s the standard pads... I haven’t even used the bike yet I only had it out the box the other day. Very frustrating as I’ve spent hours adjusting both the front and rear brakes trying to get them to spin freely without rubbing... can’t really use the bike like this as it’s going to put extra strain on the clutch etc🙄
 

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Discussion Starter · #67 ·
Hi mate nope it’s the standard pads... I haven’t even used the bike yet I only had it out the box the other day. Very frustrating as I’ve spent hours adjusting both the front and rear brakes trying to get them to spin freely without rubbing... can’t really use the bike like this as it’s going to put extra strain on the clutch etc🙄
I was working on mine for a few weeks before I was happy to ride it mate. There’s plenty setup involved. It’s all just trial and error. Try greasing everything up mate. Check how the wheel spins without the pads in. Brake cleaner on the discs. Possibly just need the pads to scrub in a bit mate.
 

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I was working on mine for a few weeks before I was happy to ride it mate. There’s plenty setup involved. It’s all just trial and error. Try greasing everything up mate. Check how the wheel spins without the pads in. Brake cleaner on the discs. Possibly just need the pads to scrub in a bit mate.
Okay mate thanks for the advice I shall give that a go, I’m sure I will figure it out in the end, I’m just dying to give it a blast!! Haha
 

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Discussion Starter · #69 ·
Okay mate thanks for the advice I shall give that a go, I’m sure I will figure it out in the end, I’m just dying to give it a blast!! Haha
I know the feeling lad! Just do plenty research on here. There’s loads to learn. Do’s and don’ts. First thing would be a proper spark plug, carbon Reed petals and check your squish. You’ll probably find you’ve got two head gaskets, remove one and aim for around 0.6-0.9mm. Might wanna get a gasket kit. Depending on the track you might want to look at a bigger rear sprocket. Just read all you can on here mate and enjoy the bike. They’re great fun to be fair. I’ve got an r6 and a Ktm sx 150, I still love blasting the little Chinese thing lol.
 

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I know the feeling lad! Just do plenty research on here. There’s loads to learn. Do’s and don’ts. First thing would be a proper spark plug, carbon Reed petals and check your squish. You’ll probably find you’ve got two head gaskets, remove one and aim for around 0.6-0.9mm. Might wanna get a gasket kit. Depending on the track you might want to look at a bigger rear sprocket. Just read all you can on here mate and enjoy the bike. They’re great fun to be fair. I’ve got an r6 and a Ktm sx 150, I still love blasting the little Chinese thing lol.
Cheers for all that mate! I’ve got a proper ngk spark plug coming for it and a few other bits and pieces. Yes your right lots to learn indeed! Once I’ve got this brake issue sorted I’ll be able to give it a blast. One last thing actually, did you bleed the radiator on yours? I’ve seen there’s a screw in one of the hoses not sure if it’s an air bleed screw.
 

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Discussion Starter · #71 ·
Cheers for all that mate! I’ve got a proper ngk spark plug coming for it and a few other bits and pieces. Yes your right lots to learn indeed! Once I’ve got this brake issue sorted I’ll be able to give it a blast. One last thing actually, did you bleed the radiator on yours? I’ve seen there’s a screw in one of the hoses not sure if it’s an air bleed screw.
Yes mate, it’s a bleeder screw. Try get all the air out the system. I got very well acquainted with my radiator hoses lol. I pushed the reservoir out so I could have straight/flat clip ons and put fancy hoses all over the place. Looks the part now.
 

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Yes mate, it’s a bleeder screw. Try get all the air out the system. I got very well acquainted with my radiator hoses lol. I pushed the reservoir out so I could have straight/flat clip ons and put fancy hoses all over the place. Looks the part now.
Wicked mate looks mint! Did you fill the coolant bottle and unscrew the bleeder screw till it’s just coolant coming out to get all the air out the system? Also I’ve Heard the stock clutches are pretty pants. So Think that will definitely be one of the first better parts I’ll invest in for it
 

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The brake pads will always rub a little, they are not fixed in the saddle and the saddle is also floating.
And you can't leave out any seals on the cylinder head, there are o rings installed.
To adjust the squish gap, you need another domecap(mostly a plus cap that prodrudes into the cylinder) or someone who will mill off the cylinder for you.
When you buy a other clutch please invest into a zocchi /bzm 3 shoe, it cost a lot but these are the best. You should also think about a bigger carb something like a phva 17,5 or a phbg 19 runs great on these engines and bring a lot cooling for the engine.
 

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The brake pads will always rub a little, they are not fixed in the saddle and the saddle is also floating.
And you can't leave out any seals on the cylinder head, there are o rings installed.
To adjust the squish gap, you need another domecap(mostly a plus cap that prodrudes into the cylinder) or someone who will mill off the cylinder for you.
When you buy a other clutch please invest into a zocchi /bzm 3 shoe, it cost a lot but these are the best. You should also think about a bigger carb something like a phva 17,5 or a phbg 19 runs great on these engines and bring a lot cooling for the engine.
That’s reassuring to hear so the rubbing isn’t too much to be worried about then? I was worried it would be putting loads of strain on the clutch etc. I’ve seen the zocchi 3 shoe nearly bought one but saw a few and wasn’t sure which one to get. I’ll keep that in mind about the carb mate, thanks for the advice
 

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Discussion Starter · #75 ·
Wicked mate looks mint! Did you fill the coolant bottle and unscrew the bleeder screw till it’s just coolant coming out to get all the air out the system? Also I’ve Heard the stock clutches are pretty pants. So Think that will definitely be one of the first better parts I’ll invest in for it
Leave the cap off the reservoir mate. Few slow pulls of the pull cord. And you’ll hear the system starting to burp and the bubbles will come up through the reservoir. Rinse and repeat mate. Try not to let the reservoir drop below around 1/3 full. When you’re happy you’ve got all the air out. Obviously tighten the bleed screw and have the reservoir just below half full.
 

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Leave the cap off the reservoir mate. Few slow pulls of the pull cord. And you’ll hear the system starting to burp and the bubbles will come up through the reservoir. Rinse and repeat mate. Try not to let the reservoir drop below around 1/3 full. When you’re happy you’ve got all the air out. Obviously tighten the bleed screw and have the reservoir just below half full.
Cheers for that mate, it doesn’t say anything in the manual it comes with about how to bleed the system! So great advice mate thanks. Read you took yours to m4 karting- great little track been there before, hopefully will be able to get Mine there once it’s all sorted and the tracks back open... have to keep in contact would be great to meet up for a blast at m4 sometime mate 👍
 

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Discussion Starter · #77 ·
Cheers for that mate, it doesn’t say anything in the manual it comes with about how to bleed the system! So great advice mate thanks. Read you took yours to m4 karting- great little track been there before, hopefully will be able to get Mine there once it’s all sorted and the tracks back open... have to keep in contact would be great to meet up for a blast at m4 sometime mate 👍
Yeah, it’s decent there mate. Will message you when I’m next going up there. It’s a bit of a mission for me to be fair but don’t know anywhere else. Need to look into it at some point. M4s good fr the shop being there though
 

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159205
The brake pads will always rub a little, they are not fixed in the saddle and the saddle is also floating.
And you can't leave out any seals on the cylinder head, there are o rings installed.
To adjust the squish gap, you need another domecap(mostly a plus cap that prodrudes into the cylinder) or someone who will mill off the cylinder for you.
When you buy a other clutch please invest into a zocchi /bzm 3 shoe, it cost a lot but these are the best. You should also think about a bigger carb something like a phva 17,5 or a phbg 19 runs great on these engines and bring a lot cooling for the engine.
Yeah, it’s decent there mate. Will message you when I’m next going up there. It’s a bit of a mission for me to be fair but don’t know anywhere else. Need to look into it at some point. M4s good fr the shop being there though
Sounds good mate. Yeah I’m the same, it’s a good couple hours away from me but I don’t really know anywhere closer, worth it though I guess if your taking your own bike as it’s cheaper than hiring one
 

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View attachment 159205

Sounds good mate. Yeah I’m the same, it’s a good couple hours away from me but I don’t really know anywhere closer, worth it though I guess if your taking your own bike as it’s cheaper than hiring one

This clutch won't fit on the Blata replica, it's for the aircooled Chinabikes.
And for an adult rider you should get a clutch with red springs or 2,5mm springs.
The blue zocchi springs are for teenager.
 
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