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Discussion Starter · #21 ·
Seriously valuable info. Thank you.

For 2.Should I stop removing material just before reaching the overflow tube?
For 5. What should the outside diameter finish at approximately?

I am going to start with the BB kit and rocket key install. I think I will use the current stock carb to practice the taper bore process if you can confirm about how much how much material to remove. I know it is a delicate balancing act of fuel and air with every carb.

As stated, my stock 13mm carb's float bowl is leaking. Can I use one of the Permatex "Form-a-Gasket Sealants" to at least temporarily stop the leak so I can test the practice taper boring? I would like to keep the 19mm carb included with the BB kit in brand new condition to resell. I know it's not much money, but principles... I also got a new Garmin Forerunner GPS at Goodwill for $14.99 that I can use for a speedometer on this and all my RC vehicles. I will try to take before pulls with it tomorrow and record on video.
 

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That's one thing I haven't tried yet is making the bowl bigger. Someday. You are on your way though, it will be frustrating at times but keep fighting through. I did my first petcock mod and let me tell you. Drill first then epoxy later. It took me 30 minutes to drill through that sucker, now granted my bit is probably bad. Lol
What size bit did you use mrkitty??
 

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The 15mm clone is the best & easiest way to get more air and fuel. Mod a stock carb first then try a 15mm. I like the 16mm clone WT-603 or WT-813 w/ accel pump. The HDA48D is a 16mm, no return line to the tank.
 

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Discussion Starter · #25 · (Edited)
That's one thing I haven't tried yet is making the bowl bigger. Someday. You are on your way though, it will be frustrating at times but keep fighting through. I did my first petcock mod and let me tell you. Drill first then epoxy later. It took me 30 minutes to drill through that sucker, now granted my bit is probably bad. Lol
What size bit did you use mrkitty??
Thanks for the pics.

1. Ditto on the bit used for the petcock delete? I’ve never take one of these apart, so I’m not sure what the petcock looks like in there. I thought it was just a 90 degree ball valve? Are you basically just opening the flow path to the largest diameter possible?

2. I’ve seen it mentioned more than once on the boards that this 19mm BB kit carb may require a longer throttle cable. The stock MTA2 cable is 28” so would I be looking for a 29” most likely?

3. Does anyone have a pic of the triple tree area without the nose fairing installed? I think I may be missing a fairing stay that supports the windshield and that something may have been cut off from the front of the frame. Pic attached.

4. Would going up 1 tooth in the front add enough acceleration to make the drop in top end RPM worthwhile and did the MTA2 come with the 8mm or 10mm front sprocket or both?

5. I can’t figure out how the chain guard pictured below would mount to the bike based on the mounting holes it has. I’m assuming at least one of the two currently unused holes in the frame would be used? What does the back hole attach to? Am I missing a mount?

6. Does going to 1/4” fuel line and filter actually make any performance gain being that you’re limited to the diameter of the source and destination on the carb? Is this only to be done with a port and polish?

I’m also thinking about going with a hydraulic brake setup and returning the anodized foot pegs for this double peg style shown below because they look more comfortable (I’m 6’3”). What do you guys think?
7AF8B0F5-0F10-4A9F-A790-5D44865A4681.jpeg 1E465361-61A7-4097-9DFF-1429889194CD.jpeg 8A3DE229-0D98-4C65-9C2C-5CDEB582FF07.jpeg 459A0DF9-C3C9-4CBB-A251-17ED5C41E91F.png 5E7522C0-0786-401A-B7DD-8C94981AB65B.jpeg
 

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The 1/4"fuel line helps, especially with modifications.
The front sprocket is usually 6 tooth sometimes 7.
Those holes would be for the chain gaurd.
The front fairing support rod broke off yours. Unfortunately I do not have a pic.
 

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The front fairing and the bracket are worthless it's the first thing that snaps off in a crash or from vibration.

Any more than a seven tooth front sprocket and your frying the clutch

There is no need for hydraulic brakes the mechanical brakes are plenty enough to skid the tires

You're definitely going to want to lock out the rear suspension to keep the chain from coming off...
 

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Discussion Starter · #29 ·
I'll probably only have the nose and sides on for show and remove them for riding. I'm going to fabricate and weld up my own nose fairing bracket. It's gonna look pretty good as a streetfighter once the frame is painted and everything else is installed anyway. I think I will wait on the 7 tooth sprocket until I see how she runs after all these mods. Instead of hydraulic brakes, I have read mountain bike levers are a good upgrade? Just selected this 1/4" fuel filter and I already have plenty of clear line. 'm loving the parts shopping phase, but the big bore is here, so it's time to start doing some work this week. Current parts link list updated in OP.
41AaWlj0MzL._AC_.jpg
 

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Discussion Starter · #30 · (Edited)
The 1/4"fuel line helps, especially with modifications.
The front sprocket is usually 6 tooth sometimes 7.
Those holes would be for the chain gaurd.
The front fairing support rod broke off yours. Unfortunately I do not have a pic.
The chain guard must be smaller than it looks because the hole on the right doesn't look like it would line up with the two holes in the frame bracket. The MTA4 chain guard almost looks more like it would fit if this pic were inverted.

Edit: the pic of the bike is how it is mounted. It appears to be bolted to the swing arm and my bracket is on the chassis.

This one looks like it would fit, but look at that price. Ridiculous.
eBay Chain Guard
 

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The cag in that picture is a gen 4 box steel full fairing cag...

There is a gen 3 round and box steel hybrid they only made it for about a year or two also known as the PS77 Cagllari Daytona

You have a gen 2 MTA2 full fairing Cagllari Daytona the one with rear suspension AKA the pogo stick a lot of people have removed the rear shock and replaced it with a piece of plumbing pipe though I've seen people get fancy with them and use Fox float RL mountain bike air shock ( 200$ + a shock pump )

Then there is the Gen 1 nothing fancy really basic all round tube and came with the original Reed inducted engine that had the 40 mm piston it was 200$ delivered...

The Gen 2 and on came with a 44 mm cylinder...

The Big bore kit is actually a 44 mm cylinder with a special piston that has the 10 mm wrist pin to fit the Gen 1s engine that came with the 40 mm bore hence the real Big bore kit

Nowadays they just call it a Big bore kit even though it doesn't really increase the bore size of your engine because they are all 44 mm from the factory and it should actually be called a two-piece cylinder kit which effectively raises the compression increasing the horsepower ( if installed and shimmed properly )
 

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Originally they were 40 mm engines back in the day then they moved to 44 mm engines. Now you're lucky if you can find a 44. 90% pocket bikes I come across have 40 mm engines.
However, that chain guard I would redrill the shield where ever you need to make it fit. Parts you will buy unfortunately might look correct but come wrong. It's like old school hot roddin, you have to modify to make stuff fit and work. Don't be afraid.
6 tooth sprocket is great for a stock engine however the way the chain wraps around there is a kink. 7 tooth is the best, you can run an 8 tooth but you got to make sure that the engine has enough power by being highly modified unless you run a bigger rear sprocket with the 8th tooth front 2 offset and get the correct ratio that you were looking for and that your engine can use.

I personally love the Cag's with the shock in the rear. I am tall and it fits me better.
The ride is fine, dont jump curbs (with any bike) and you will be fine. Lol
 

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I’ve taken a lot of these stock carburetors apart, has anybody else seen the needle jets that are straight and have only one adjustment? That is such garbage. I’ve seen two or three of those. Are usually just steal one out of a parts carburetor
 

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I’ve taken a lot of these stock carburetors apart, has anybody else seen the needle jets that are straight and have only one adjustment? That is such garbage. I’ve seen two or three of those. Are usually just steal one out of a parts carburetor
Yes they were entertaining the idea of trying to make the carburetor not adjustable to meet EPA standards before all two-stroke rideables were banned in the US. ( Yes I understand some are still slipping through )
 

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Discussion Starter · #37 · (Edited)
Finally got a decent day to do some baseline top speed pulls. 66 degrees F 5PM. Top speed is 23.1Mph as the bike sits with no tune check or maintenance, a leaking float bowl, loose chain, and other issues. I’m going to try to fix the float leak with some fuel resistant Form-A-Gasket and take another baseline. Then modding the factory carb and pulling the motor to inspect it and determine if I want to keep the 44mm big bore kit.
578F8794-66CF-47AE-B4A5-08257AA28659.jpeg 76CDD78D-5FC2-4F54-9767-D4E07E0FEC2A.jpeg
 

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Gasket maker, now your on the right track, think the gauge is a little over kill, lol. Can you see it while your riding, My pegs are on the rear axle w/ 10 speed pedal toe clips and I lay on the tank so my head is over the handle bars, that's why I don't run a gauge. My $12 laser temp gun I us for engine temp. Great project can't wait to see what you come up with next.
 

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Discussion Starter · #39 · (Edited)
Gasket maker, now your on the right track, think the gauge is a little over kill, lol. Can you see it while your riding, My pegs are on the rear axle w/ 10 speed pedal toe clips and I lay on the tank so my head is over the handle bars, that's why I don't run a gauge. My $12 laser temp gun I us for engine temp. Great project can't wait to see what you come up with next.
The GPS is worn on your wrist and it automatically records and displays the top speed when you stop. The pic above is after I’d made several runs. Yes it’s not convenient or safe to look at your wrist at top speed lol.
As for pegs, I found a sweet spot for them in the stock location so they don’t drag on curves and it’s still comfortable. I also got a Vivitar action cam with a bunch of accessories for $6.99 at Goodwill and mounted it on the fork. I need to edit the video and I’ll post it.
 

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