Doodlebug - Stretch

noseoil

Active Member
#21
Thanks, is there a supplier for thicker brake rotors with the 6 hole, 180mm X 37mm which is the thinner one on the Doodle Bug? It has good grip now & is firm with no slop at this point.
 

noseoil

Active Member
#22
After putting in new bearings for the steering, I still have a lot of slop in the forks. The holes in the top & bottom plates appear to be really sloppy & drilled oversize. Since it was a basket case, I'm wondering if there are stepped washers which go in the forks (top & bottom) to take up the slop & I don't have them to put back in. Anyone know about this one?

If not, I'm going to have to make some bushings or something to take this slop out of the front end.
 

noseoil

Active Member
#23
Finally got the idle jets in from my order & started playing around with the mixture setup. Needed a #20 on the idle jet & had to drop to a 90 for the main jet (6,500'). This is a weird combination for me, compared to other setups I've done up here. I guess the carbs are all a bit different on the Chikuni's & they are all "custom made" with respect to the inside passages, but this is a strange one for sure.

It's finally pulling up to the top end now with this setup, but I need to change the jet-needle e-clip in the mid range pull, as it's still a little boggy in transition. I've pushed my luck enough for one day here in the 'hood making noise. Finally getting some good rpms & the top end is decent for a change. Will get a tach in place soon, add a steering damper (still a bit squirrely at the high end) & figure out the slop problem in the front end. It's running better & the frontage road is a nice, long straight where I can test the tune better & run next to the semi-trucks coming into town at the exit ramp, safely. Will report back with the GPS speeds when thing are broken in more & it's running better.

I've ordered a new brake rotor made out of 1/8" stainless steel, which should arrive soon as well. The hydraulics are doing the job, but there needs to be more meat back there with the higher speeds & heat for stopping.
 

noseoil

Active Member
#25
Took the steering apart & ordered some bushings to fix the wobble in the front end. Basically, they're 3/8" ID X 1/2" OD flange bushings from McMaster-Carr & I drilled out the holes to 1/2" so once they arrive, I'll put things back together & add the steering damper while I'm at it. Should be plenty stable that way (no death wobble) & ready for a run or two to see how the motor does. Will take a few pictures of the fix as I assemble.
 

noseoil

Active Member
#26
The bronze bushings arrived earlier today. They are 3/8" ID X 1/2" OD with a flange on one side, so it's a good fit. Here's how it went, had to drill them out to 10mm (they were 3/8" so a few hundredths too small) to get the bolt to fit, then put things back together & do a little touch-up with the paint to make it look 100% again. This stuff is fun & I'm enjoying the problem solving on this build.







Next will be the steering damper, should arrive next week. Tach showed up this afternoon, so it'll get installed tomorrow at some point. Out of time tonight for work. Little by little it's getting done & doing better all the time...
 

noseoil

Active Member
#27
Got a new brake disc from Frank Franquez (F&B Racing) today & installed it. It's 1/8" stainless steel, perfect fit & nicely made easy swap.



Also, the steering damper arrived early, so it's in place. Much stiffer steering now & tight with no slop at all!

 

noseoil

Active Member
#28
Maxed out, here's what it does now at 6,500' of elevation, it's pretty thin air up here.

This is with the 22mm Chikuni, CM grind Hemi .265" lift cam, shaved & ported head, header & 15" tire with a 4.8:1 final drive ratio.

TopSpeed.jpg
 

noseoil

Active Member
#30
I'm not sure, don't have marks to run it on on the pavement, but it's pulling well enough & runs up to 7,000 rpm's quickly now. It's a cheap motor the way it's built.

To do better, I'd need to move more air through the motor; larger valves, carb, more compression & a taller cam would do it, but I'm happy the way it is now. At that point I'd need a forged piston and $$$.....
 
#32
Maxed out, here's what it does now at 6,500' of elevation, it's pretty thin air up here.

This is with the 22mm Chikuni, CM grind Hemi .265" lift cam, shaved & ported head, header & 15" tire with a 4.8:1 final drive ratio.
What sprockets are you running front/rear?
 

noseoil

Active Member
#33
It's 10:48 at this point, which ends up being 6,500 rpms @ 6,500' of elevation & the 15" rear tire for 60+ mph on a flat road. It pulls well to that speed, then maxes out trying to push the air out of the way.

I'm losing about 20% of my hp with this thin air. It would run much better with thicker air at sea level, but it's cooler up here in the summer. It's a fair trade from living in Tucson (2,600') all of those years with 100+ temps 6 months of the year. At least in the summer I can work out in the shop & enjoy it, although it's a bit chilly in the winter months.
Knife-making when it's too cold outside is fun... 1-d2-2nd2.JPG
 
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