Added reply in a thread Anyone ever had any success repairing cracks in plastic gas tanks? 9/26/2017 10:18 AM

Added reply in a thread Anyone ever had any success repairing cracks in plastic gas tanks? 9/23/2017 7:30 AM

I wish I had a story for the .22 slug buried in the tank. Bike was purchased in the back woods of New Hampshire. That may be the best explanation in itself.

Added reply in a thread Anyone ever had any success repairing cracks in plastic gas tanks? 9/22/2017 3:43 PM

It can leak if you don't do a good job welding. However , if you get good penetration and no voids, it should last longer than your interest in the bike! Just like welding anything. I got a little more gas smell during welding, but a dry tank can't be ... more »

Added reply in a thread '78 RM125 Restoration 9/22/2017 11:00 AM

Nice Build! I'm curious to see what you find for shock therapy. I've got the same dilemma on a '79 KX and '79 KLX. Non-Rebuildable and nobody offers anything close with reservoirs. I have seen Arctic Cat showmobile shocks made by FOX that may be worth ... more »

Added reply in a thread Anyone ever had any success repairing cracks in plastic gas tanks? 9/22/2017 6:55 AM

You're right notme. The only thing that will permanently bond to HDPE is HDPE. There are products that come close, but plastic welding is the best because it "co-polymerizes". I usually use the tip of that welding nozzle to create the "V" by "plowing" ... more »

Added reply in a thread Anyone ever had any success repairing cracks in plastic gas tanks? 9/21/2017 12:57 PM

I made a plastic welding rig out of a nozzle for my heat gun.

Ordered 1/4" HDPE rod from McMaster-Carr and welded up a few tanks. Here's the KX80 tank I had to re-work to get the XR100 motor to fit. Most tanks are an HDPE mix of some ... more »
Added reply in a thread YZ125 ignition mapping? 7/5/2017 6:58 AM

I raced the bike last Saturday in a Vintage Hare Scramble. Here's what I found out: *Will the additional weight of the external flywheel make the bike easier to ride? YES. It could use even more Flywheel Weight for New England woods, but awesome for

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Added reply in a thread YZ125 ignition mapping? 6/30/2017 10:32 AM

Here goes!!! After a bunch of research, I found that the 2000-2001 YZ250 ignition has the same 110mm backing plate and crank taper as my bike. (No YZ125 system would fit). It's a full digital system, so I can swap the CDI box to a programmable one in

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Added reply in a thread YZ125 ignition mapping? 6/8/2017 5:41 AM

HPI looks good! Because the original Hitachi Ignition is Analog, nobody makes a programmable CDI box that will work with my Rotor / Stator. I'm going to research if I can fit a 2000 YZ125 Rotor / Stator to my bike and use an HPI programmable ignition ... more »

Added reply in a thread YZ125 ignition mapping? 6/7/2017 6:59 AM

Welp... I looked at the timing last night. It was retarded by about .010", so I timed it to slightly more advanced than factory spec. (Factory calls for .043" BTDC and I set my bike to .045" BTDC). I will report back on any noticeable change in feel.

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Started new thread YZ125 ignition mapping? 6/6/2017 9:20 AM

Hello All, I've finished my motor build YZ125 1979 Race Build and the bike has a boatload of top end, but is still lacking in mid range. I haven't played with setting the ignition timing, but I've got a hunch that the motor will respond well to advancing the ignition ... more »

This forum thread has 8 replies

Added reply in a thread YZ125 1979 Race build 5/17/2017 11:24 AM

I never measured the cranked compression. I assume it would be about 160psi. The math says it should be 183, but that's bogus. My UCCR is actually 13.5:1. After milling the bottom lands, I flipped the head over and milled the Spark plug hole and stud

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Added reply in a thread YZ125 1979 Race build 5/17/2017 10:39 AM

Gotta start somewhere... It's a casting after all! ... more »
Added reply in a thread YZ125 1979 Race build 5/17/2017 10:34 AM

Thanks for the compliments! I'm only into it for about $150. Comparing the astronomical prices of DG, FMF and Webco heads, this was a no-brainer!

See the two flats I milled on the under side of the fins? That's how I got a surface to reference. ... more »
Added reply in a thread YZ125 1979 Race build 5/17/2017 7:37 AM

I'm going to try to upload the pics in order for ya. It was a pretty easy mod.

Before Top Before Chamber After welding. Stud holes drilled and plug hole tapped Machined Chamber (see porosity) Top Machined ... more »
Added reply in a thread YZ125 1979 Race build 5/15/2017 7:27 AM

Couple crappy Pics, sorry.. Got the Cylinder all set, 34mm Mikuni, 6-petal YZ400D reed cage and a modified '74 Penton ISDT125 radial head, and added the RF boost bottle. Gained a bit in the mid, but top end just shreds. Never had a 125 wheelie up a sand

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Added reply in a thread Any experience with plastics? 12/20/2016 9:36 AM

5 gal buckets are made of HDPE. That's what you want. McMaster Carr will have HDPE in different sheet thicknesses. You can heat and form it easily, but you can't bond it. I wouldn't use PVC as it's more brittle and scars more easily as well. However,

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Added reply in a thread Old school mini Mx bikes...50cc-100cc 8/29/2016 11:42 AM

Here are a couple of my mini's. Fun stuff. I seem to crash harder and more often on a 50 than a 250... SMH. QA 50 set up for mini Sumo.

82 YZ60 with a bunch of 80 parts. The only one I "restored" and now can't ride ... more »
Added reply in a thread Something cool happened to me today! 6/7/2016 9:03 AM

Great story!!! IMHO, keep it stock and get it up into that house! Here's mine. That front Number Plate is going to be a tough one to locate.... Good luck!

Added reply in a thread YZ125 1979 Race build 5/11/2016 8:22 AM

I had a little more time to play in the shop. Turned a spigot for the carb boot and installed that. Also noticed that the boost bottle spigot at 90* doesn't really want to fit on the bike, so I cut and laser welded it back on at an angle. I wasn't going

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