AlisoBob's Gen 4 A/F Conversion

Post by **AlisoBob** » September 28th, 2007, 11:05 pm

Ok bitches... I'm pooped... not from the conversion, but getting this thing torn apart!!!!

Joe and I spent 4 hours taking it apart... ( Wiring, allot of hoses, fittings... all kinds of shit.... ) and about 45 minutes of Sawzall work to actually fit the motor.

I'll get the "Y" refitted and the cradle reattached pretty quickly. The other logistics look pretty simple, with the exception of the fuel tank being able to hold a decent fuel load. I'm still considering building either an Alloy one, or composite.. we'll see how it works out.

2 A/F's roughed in in one day.....

1- 2002 CR250R

1- 2004 CRF250X

Too Cool!

Time to clean up, and kick it. I'll post up some more photos tomorrow...

lewisclan · Post by **lewisclan** » September 29th, 2007, 7:09 am

composite

lewisclan · Post by **lewisclan** » September 29th, 2007, 7:11 am

with 3 weeks out on the glamis ride looks like you will be riding the cream in the sand box eh.
Those are some sweet looking bikes guys

sabreguy · Post by **sabreguy** » September 29th, 2007, 7:26 am

Hey I have an

!!! Since you have a Gen 3 and a Gen 4 side by side take some pics of the differences between the two and post them up. I mean you are already doing a side by side build up so just emphasize the things that had to be done differently and do a side by side comparison of the two builds.

Post by **AlisoBob** » September 29th, 2007, 8:53 am

Well , heres where it started... " I'll just take a few minutes to strip the bike and then we'll begin the conversion"..... WRONG!

The only thing worse than paying the repair bills on a 4 stroke is working on one. I work pretty quickly and it took forever to take this pig apart... 1.25 hours just to get the subframe off as an example. The carb was another 45 minutes or so...... If I had to perform the maintenance on my own 4 banger, I wouldnt ride it either..... WAY too much hassle.

About 8 seconds after the motor was out, Sawzall was put in action.... 1,2,3 Done!

2 minutes after that, the dummy motor was in place... SWEET! These are Gen 1 mounts. They fit the Gen 3 perfect, and look serviceable in the Gen 4 as well. Contact either Danny Graves, or Shanman for price and availaibility. These mounts RULE!!!!!

The motor is hard over to the right, and the chain alignment is pretty good, but I got a gap on the left side. I have lots of bushings and washers to play with. I'll get it right, with OEM stuff like the Gen 3 bike.

Overhead shot.

This is a shot of the interior on the "Y". Its an investment casting, with pockets machined to accept the down tube and cradle pieces. Once I get the cut off stubs out, its pretty straightforeword to cut the down tube higher, slap this puppy back on in its higher location to clear the pipe and buzz it back together.

It was honest -to -god 4 hours to take it apart, and 45 minutes to do the rough conversion.

I'll post up the reassembly of the "Y" once its done.

If ANYBOBY is the slightest bit concerned about trying this for themselves... CONTACT ME! If you can change your own oil, and have access to a Sawzall, you can do this!!!!

I'll walk you through it.....

britincali · Post by **britincali** » September 29th, 2007, 8:56 am

Why you gotta call my awsome motor a dummy? Shes gonna get her feelings hurt

"I'm glad you can use it, enjoy it forever.... buy me a beer at the next ride and were even....." Edited by the bobber......

Im sending you a bill for $150 now

You like that edit button so much we should rename you VH

Post by **AlisoBob** » September 29th, 2007, 9:49 am

Send the bill to my business address....

britincali · Post by **britincali** » September 29th, 2007, 9:52 am

AlisoBob wrote:Send the bill to my business address....

Your wifey said she'll pay it as soon as she gets it

ou812 · Post by **ou812** » September 29th, 2007, 9:54 am

I'm getting tempted to do a beer can bike.

Post by **AlisoBob** » September 30th, 2007, 4:11 pm

lewisclan wrote: Those are some sweet looking bikes guys

Thanks Jay, that A/F of yours aint going to be "Butter Face" either....

Hellbear · Post by **Hellbear** » October 1st, 2007, 1:50 pm

It's looking good Bob.

Post by **AlisoBob** » October 2nd, 2007, 3:21 pm

This is why I like the Gen 4 so much...

You have to move the "Y", but its so simple.

1. Cut off the Y

2. Remove old downtube and cradle pieces from the pockets

3. Cut downtube higher up to raise Y

4. Reassemble and weld.

Here is the "Y" with the downtube piece removed. The machined pocket that accepts the downtube is clearly visible.

Another view showing its ample opening for the exhaust flange.

Easy enough?

Slomo · Post by **Slomo** » October 2nd, 2007, 5:29 pm

Looking good Bob.

When you gonna do a blue bike?

Post by **AlisoBob** » October 2nd, 2007, 6:00 pm

After riding Justins YZF450, you dont know how close I came...

Rosco-Peeko · Post by **Rosco-Peeko** » October 2nd, 2007, 8:48 pm

Good work Bob, cant wait to see the finished product.

sabreguy · Post by **sabreguy** » October 2nd, 2007, 8:57 pm

What is the reasoning for cutting off the three pieces that are laying in front of the Y in the second pic? Are they going to be welded back on?

Post by **AlisoBob** » October 2nd, 2007, 9:21 pm

Na, I was sending that photo to someone else to show them that when you cut that much of the weld off, you can remove the stubs...

iggys-amsoil · Post by **iggys-amsoil** » October 2nd, 2007, 10:03 pm

I think its a better design than the clam shell type.

At the top part of the Y, are you gona plate the front and rear?

Post by **AlisoBob** » October 3rd, 2007, 8:20 pm

No, the intersection between the Y and downtube is about 9/16" of an inch.

.......Plenty

Stock, the front does has a thin plate welded on. It appears it is to keep the fender from rubbing a slot on the downtube.

Its not structural.

Post by **AlisoBob** » October 9th, 2007, 8:52 pm

Motors in!!!

Well... sort of..

The "Y" has been relocated. Its about 3.5" higher than it was. It indexes about 1/2" over the down tube. Look at the slice laying on the floor. These Gen 4 downtubes are stout!! There is plenty of room ahead of the jug for the radiator cross flow hoses to go. I cut off the un-needed tabs and sharp welds. I still need to make the lower mount tabs, and find the correct bushings and spacers to center the motor on the swingarm, but its almost done and is going to look very factory!!!!!

The motor is actually shorter than the CRF250 motor, and access to the carb from the right side is unreal! These 4 banger A/F frames were made to convert!!!

Lots of room around the "Y" to get the manifold, pipe, and springs in there.

This is just Home Depot 1" tuning to mock everything up, but Shanmans mounts line up well. I have now used these mounts on Gen 1, 3, and 4 frames. They are fantastic! This tubing is square edged,not the rounded corner tubing that Honda uses. The mounts will fit even better with the correct tubing. The 1" sutff will also index into the "Y" and the existing cradle pieces.

Another 3 hours into the build log.

britincali · Post by **britincali** » October 9th, 2007, 8:58 pm

LOL that motor looks horrific in the pics

You can even see where I helicoiled the bottom exhaust bolt hole off center....

It worked tho

iggys-amsoil · Post by **iggys-amsoil** » October 9th, 2007, 11:22 pm

Get the spacers for a 03 CR125. Per AJ. Thats what I did.

HrcRacing · Post by **HrcRacing** » October 10th, 2007, 5:57 am

Looks good.

97af · Post by **97af** » October 10th, 2007, 10:09 am

AlisoBob wrote: Motors in!!!

Lookin' good Bob!
Hey,How many and what kind of batteries is that "motor" going to run on?

Post by **AlisoBob** » October 10th, 2007, 10:39 am

Talkin' to Brit too much again...

Viva' la ENGINECycles!

BannedCR500Riders.com

AlisoBob's Gen 4 A/F Conversion

AlisoBob's Gen 4 A/F Conversion