Dorothy, Heald VT-7 (anything goes) project ...

Mini Bike & Go-Kart Parts

#21
Kevin,
I am really enjoying your build thread and watching the bike come together. As a fellow Super Bronc owner (1974 VT-8) I am especially interested in this performance build you are doing. I believe it is precedence-setting, at least on this forum, as I have never heard of anyone doing this on a Bronc before. I will candidly admit I am VERY envious of your fabrication skills and easy access to specialized equipment! I doubt that are any parts that you cannot make. Please keep the updates coming.
Michael
Thanks for the kind words amigo ...
All the performance stuff I see being done is street specific ... I find myself off road more often than not .. I'm curious how this is going to turn out too!
 
#23
ole4 says the hole in the lower front of the carb is needed for jet adjustment ... the gasket made a little room but I ground a little relief on the intake for air flow.

Question is does this need to be filtered for off road use?
 
#24
Running the gas line was easy, behind the flywheel next to the motor like HS50's etc ...
I had to step it down from 1/4" I.D. to 3/16"(?) I.D. ...
I took a 2-way 1/4" brass barb, put it on the lathe and spun the barbs off one side ... then used simple green to make it slippery, used hose clamps to secure it.



But it looked to me like the pink hose might kink ... I found a light spring that the hose just fits in and put it over the hose ... should keep it from kinking.

 
#25
Got the 3D Clutch on ... only issue I had was it came with a 5/16-24 flat head, I needed a 3/8-24 flat head, off to the hardware store ... there is plenty of room for the bigger screw.

You can also see I added an extension to the oil drain plug to keep the mess contained when draining the oil.

IMG_23951.JPG
 
#26
Latest issue is the throttle cable .. it came assembled with the adjuster and both nipples in place, the inner cable is too long.

The Jackhammer throttle (centered in the pic) wasn't milled deep enough to accept the barrel nipple so I used a stand in for this pic and to get an idea how to correct this.
with the carb side connected it looks like this ...


I will take it to work tonight and make some kind of extension/adapter to make it fit.

Ya know for what's describes as a "kit" the intake and throttle cable don't lend themselves well to my project.
They were described a being for a Clone so maybe that's it?
22MM MIKUNI CARB KIT PREDATOR 212/GX200/GX160/HONDA CLONE. Drift Trike, Mini Bik | eBay
 
#29
Fixing the Throttle grip was easy ... put it in a V-Block, clamped it in the mill, chucked up a 1/4" end mill and sunk it till the nipple went in.


I didn't want to remove the grip so I used a quarter to keep from schmucking it up ...


To fix the cable being to long issue I made a longer cable adjuster.
The threads on the cable are 10mm x .125 and I re-tapped the throttle to receive 3/8-24 threads.
I took a 3/8-24 socket head cap screw, cut the head off and welded the 10mm x .125 nut to it.
A slitting wheel was used to make the cable slot.
Cleaned it up with a wire wheel on the snag grinder.
 
#30
At this point the bike is aesthetically pleasing to me.
The seat, fender and exhaust are not ... I will work these out later ...
I'm not sure what I'm going to do with those ... for now I want to get it running and shake down the mechanics ...
I put a gas filter on the breather so nothing gets sucked into the crank .. that's what destroyed this VT-7's original motor ..
Looks goofy but it will do for now.

The frame is just white primer but it is growing on me ... Hemi Orange was my initial thought ... hmmmm ....



 
#31
A quick shout out to all you who chime in with kind words, advice and support .. Thanks!
I'm something of a social leper and I don't always respond to comments but all are read and appreciated with advice considered and welcome!

Thanks
Kevin
 
#32
A quick shout out to all you who chime in with kind words, advice and support .. Thanks!
I'm something of a social leper and I don't always respond to comments but all are read and appreciated with advice considered and welcome! Thanks Kevin
All good Kevin. I'm a social "leaper" myself, and have been nominated several times to head up the OldMiniBikes official newbie welcoming committee.

I was wondering....you could have just got a 9 dollar mini bike throttle cable and soldered on a brass tube on the end for the Mikuni, and did some filing for the throttle if the ball end didn't fit. Or I missed something. Disregard if I did, I hate to derail build threads with side bar comments.
 
#33
All good Kevin. I'm a social "leaper" myself, and have been nominated several times to head up the OldMiniBikes official newbie welcoming committee.

I was wondering....you could have just got a 9 dollar mini bike throttle cable and soldered on a brass tube on the end for the Mikuni, and did some filing for the throttle if the ball end didn't fit. Or I missed something. Disregard if I did, I hate to derail build threads with side bar comments.
Hi Dave ... I have thought about making my own cables, even looked up how to do it ... funny you would mention making one .. I brought my cable and carb into work yester day and my buddy said I should just make one .. guess that's on my list of things to try ...

As far as the throttle goes I didn't like how it held only 1/2 the barrel ... milling it so the barrel seats correctly and is held evenly on both sides might save me some trouble later on.
 
#34
Looks great Six!!............Looking foreward to seeing how it shakes down, still think you may need to put a larger sprocket on the driven side of jackshaft.....................Tom.
 
#35
OK, today was the day ... everything is ready .. I added a wire from the kill switch to the motor to make sure there is a solid ground should I have to shut it down. I went out and got 1 gallon of 110 octane gas .. why not!?!
Placed it against the garage wall, set the clutch lever to hold the clutch open. Flipped the choke down and pulled, nothing, pulled 11 more times, nothing ... hmmm ... troubleshooting in my head has begun! Did I set the cam right? Ground the kill? Open the petcock? Its got compression for sure!
Pull the air filter, spray some starting fluid, nothing.
I pull the plug, I see spark but its between the plug and the head ... I grab another new plug, gap it to .030, put it in, 2nd pull ... Varoom!!

Here is a short video of this motor running for the 1st time since it was manufactured in the mid(?) 90s.
[video=youtube;wQA-NvSFw3U]https://www.youtube.com/watch?v=wQA-NvSFw3U[/video]

We have 20 mins to play till I need to change the oil ... I feather the clutch out, get her going and quickly realize the gearing is WAY to tall ... below 10 miles an hours its chugging to stay running and the clutch needs feathering to keep the motor running ... acceleration is about what you would expect with gearing like it is.
When your going 10 to 15 and you dump the clutch the bike lurches forward so there is something there ..
Twist the throttle and it gets up to speed,35 and climbing and then starts to stutter like a fuel issue ... I need to keep riding for my 20 mins so I play with the choke (leaky intake?) and play with the flex-jet ... the jet just seems to make it idle faster or slower.
After 25 mins of cruising the neighborhood I pull it in and change the oil .. you can see the break in particles in the sheen of the oil. Filled it back up .... I put more gas in it thinking maybe the 1" I put in the first time wasn't enough. I didn't want to fill it in case there was a leak. I also took the gas filter off the crank breather tube ... took her out again .... still stuttering on top ... Then I pulled off the air filter ... stuttering is gone!!!
Winds out on top like it should .. I don't know the RPM but it was above 3600 .... I bought a Tiny Tach, it came in the mail just before work ... I will put it on ...

So the carb "kit" I bough has a air filter and intake and throttle cable that were not suitable for my application ... hmmm.
 
#36
The gearing ratio on my Bonanza is 5:1.........Suitable for running down the pavement at 35mph but not off road, I think you will need to be in the 8-9:1 area for snappy trail riding.....................Tom.
 
#38
Do your ratios have tire height factord in?.............Before you disassemble spin the rear wheel one revolution and count clutch revs, we can go from there.................Tom.
 
#39
Didn't your motor come with a tillotson 365b carb? I am sure the mikuni is fine and probably flows a bit more anyway. What is your current jetting? My motorsports came with a fuel pump and tillotson but it appears your tank bottom is higher than or equal to carb float bowl correct?
 
#40
Didn't your motor come with a tillotson 365b carb? I am sure the mikuni is fine and probably flows a bit more anyway. What is your current jetting? My motorsports came with a fuel pump and tillotson but it appears your tank bottom is higher than or equal to carb float bowl correct?
I opted not to use the Tillotson stack side down for 2 main reasons, one was linkage and the other was access to the adjustment screws as they are on the exhaust side. The other 2 reasons were I would need to make a intake which I had to any way with the Mikuni and figure out a air cleaner like I will now have to do with the Mikuni. The "kit" wasn't all it was cracked up to be.
If the stack was up it would have been workable but you said it would drip raw gas so don't run it up.
The tank is indeed above the float bowl.
I chose the this particular Mikuni (22mm oval bore) in large part after reading a carb thread where you said these were great carbs.

Currently the jetting is whatever it came with ... I want to get the gearing better then the jetting or what not is next ...
I want to get the Tiny Tach hooked up so I can see what my RPMs are ...

Your oil change advice was spot on ... fresh Valvoline race oil is in ther ready for its hour of run time ....

What oil do you recommend after break in?
 

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