Trevor's GX390 mini drag bike

[2kdime]

Wish I would have got some before pics but I have begun tearing into the motor and have ordered some goodies and sent some off for porting/polishing/valves/springs

Considering getting it stroked while I get the crank turned down

NIB Honda GX390
.360 lift cam
1.3 Raceseng Rollers
Billet fly
Billet rod
Tomar 3 disk
Mikuni Super BN 38mm
3 stage header


Waiting for my frame to be ready mid August and then hopefully stuff starts feeling more real.

Looking forward to updating and making some friends along the way.

Trevor

 

[bowtiebutler]

Sounds like a fun build you have going there Trevor! I look forward to the updates!:thumbsup:

Matt

 

[2kdime]

So while test fitting the cam I have found that at least 1 of the lifters binds up and keeps the cam from spinning and pushing the lifter to full lift.

Apparently the lifters have a slight bevel keeping them from going all the way in.

Can you like, counter sink the holes to allow the lifter to go higher?

Different lifters?

 

[rmm727]

You can countersink the lift bores. That was common with the Briggs flatheads.

 

[2kdime]

Thought that'd be the best choice.

Didn't want to try and shave the lip off of each lifter.

Thanks brother

 

[jdogg]

Thats a nice start there Trevor!! Whats the frame going to be?

 

[2kdime]

Mark at Outlaw Fab shop is coming out with a new drag frame, the first is the prototype, second should be mine and slated for mid August

Wanted the Nitro 44 but not a fan of the single back bone

Picking up a roller from him and then dropping this in it

Likely gearing for 1/8th

 

[2kdime]

Crankshaft is machined, pics to come

But I remember during a test fit that the new high lift cam hits the crank counter weight

Its best to grind away a little of the lobe rather than the crank isn't it?

 

[isaiah3g]

Looking forward to this. Its cool seeing someone build these bigger motors.

 

[2kdime]

Surely something yall have seen before but never the less

Just need to figure out the best way of attaching it to the crank.

 

[bowtiebutler]

Crankshaft is machined, pics to come

But I remember during a test fit that the new high lift cam hits the crank counter weight

Its best to grind away a little of the lobe rather than the crank isn't it?

I machine a little off the crankshaft when I run into this. I just ran into this a couple weeks ago on my Briggs Flat head when I installed a Dyno 03ss cam in it.

Matt

 

[waterdog]

Sounds like you've started a sweet build, outlaw frames are badass. Which frame did you order?

 

[Bruceo]

Crankshaft is machined, pics to come

But I remember during a test fit that the new high lift cam hits the crank counter weight

Its best to grind away a little of the lobe rather than the crank isn't it?

You sure don't want to grind on a cam lobe. Grind on the crank counter weights.You may want to see if you need to rebalance the crank if you do.

 

[2kdime]

Got the crank ground down with around .050 clearance on all points

Now just dealing with the timing marks not lining up real true

 

[Bruceo]

Do they sell a timing tape for that size flywheel? Find tdc and install it.

 

[2kdime]

Well I pulled the trigger on a SNIPER frame from Mark at Outlaw Fab

Time to get this thing putting some power to the ground!

Ported/Polished head with 40/35mm should be here this week. Pics once its here

 

[125ccCrazy]

Well I pulled the trigger on a SNIPER frame from Mark at Outlaw Fab

Time to get this thing putting some power to the ground!

Ported/Polished head with 40/35mm should be here this week. Pics once its here

parson's head?

 

[2kdime]

No on the Parsons, they don't go that big do they? I thought it was 38/33

I hooked up with Charles aka Minidragbike

I sent my stock head to him for porting and polishing and then the large valves.

Could have gone bigger but trying to budget a bit

Will likely get a feel for it and then weld the head up later and go larger on the valves.

 

[125ccCrazy]

No on the Parsons, they don't go that big do they? I thought it was 38/33

I hooked up with Charles aka Minidragbike

I sent my stock head to him for porting and polishing and then the large valves.

Could have gone bigger but trying to budget a bit

Will likely get a feel for it and then weld the head up later and go larger on the valves.

Found this one on ebay, Pro Velocity Cylinder Head Ported Polished Milled Honda GX390 Head Kit | eBay

 

[2kdime]

Didn't think they went to 40, but alas my exhaust is a bit higher still.

Does it not come with upgraded springs?

Wonder if it's a Honda or a clone head