Dirtbag Oil-Boiler

[doc_rot]

I moved a couple months ago and am no longer commuting 100 miles everyday so I can have a daily rider that has shorter service intervals. I've been wanting something vintage and cool, but not too nice so that I worry about it. Enter this '86 GSXR 750 i picked up for cheap recently. My plan right now is to get it on the road, ride it, and not do anything too crazy. I'm going to attempt to do my own "dirtbag challenge" and build this thing for less than $1000 including the purchase price. I think its doable because this project is pretty complete (came with a box of parts), I have a ton of parts just laying around collecting dust, and I have a friend who used to race these bikes who has a garage full of parts that he will let go for cheap.

The history of this bike that was related to me from the seller is this; his father bought this bike new, hopped it up, rode it a ton, and then sold it in the late nineties. Earlier this year he saw a guy driving this bike around and realized it was his dad's old bike so he chased him down and bought the bike off the guy. He didn't have the time or money to fix it up so he passed it on to me. Obviously his dad loved it because there are lots of cool parts on it but whoever owned it after him did a real number on it.

First thing to tackle is the wiring; its a total rat nest. The PO already started stripping it out to fix it. I found a PDF of the service manual, and am trying to determine what parts are missing from electrical system. For a second I thought these bikes didn't have a regulator, but after scrutinizing the diagram it appears its in the alternator.I'm going to wire it first just to run to see if this turd is worth building, if it cooperates and runs then I'll do a proper harness. Heres some pics.

 

[irk miller]

Re: Dirbag Oil-Boiler

Those forks are so fun.

 

[doc_rot]

I can't decide if I should keep the 16" front Dymag, or use a set of Bandit 1200 wheels, rotors and 6 pot calipers my buddy offered up

 

[whynot]

Cool, I gotta watch.

 

[1fasgsxr]

I am so watching this one !!

 

[Popeye SXM]

Great bikes the gsxr 750 even by todays standards. Me I'd go with 6 pot brakes, I find they give more ''feel'', always a good thing on a commuter. I hope this one doesn't give too much trouble

 

[Maritime]

Sign me up. looks like fun

 

[The Limey]

Ooh, a Flexi Flier. I've always had a soft spot for those old slabsides. Good old fashioned hairy chested machines. Watching with interest.

 

[doc_rot]

I hacked the wiring and it fired up with a squirt of starting fluid. I then pulled the carbs and suspecting they were super dirty, took them apart. Turns out they are RS36 flat slides. Nice upgrade for a hot motor. Also it appears the slide pivot shaft is held on with spring pins. What is the best way to remove these without doing damage? I really want to do a deep clean on these carbs because they are so dirty.
https://youtu.be/xMxB4B0Xjkw

 

[jpmobius]

I just drive them out with a pin punch, but you do have to be careful. It's very important to back up behind the pin properly. Sometimes I will make a back up plate with a finger or arm that fits up into where the pin is out of a piece of steel angle or plate that I can clamp securely in a bench vise. Drilling a hole in it for the pin to pass through will provide good support so you don't damage anything. Getting someone to hold the rack accurately on the back up while you tap out the pin(s) helps a lot.

 

[Streetfighterkz]

Look into SRAD Gsxr600 4-piston calipers. Zrx owners upgrade to those over the stock Tokico (same caliper as B12/Busa/Gsxr750W/1100W).

Btw, I had a odd relationship with the ‘89 Gsxr750 I used to own. Always wanted an O/C Gsxr so I found it cheap then barely rode it. Maybe I’d have like it more if it was a 1100?

Later, Doug

 

[doc_rot]

JP- made a finger and hammered em out. Worked good. Doug- I'll check out those calipers. I want to upgrade the brakes. It already has EBC pro-lite discs.

 

[doc_rot]

Carbs are disassembled, and I soda blasted everything and did an initial clean, focusing on cleaning out the needle bearings and regreasing them. Most of the rubber is rock hard so I will replace the o rings, and a couple other things. The header basically has barb wire holding things together and the back mount was held on with a piece of a door handle. I assume the primaries slip out of the bolt on flanges? Seems pretty stuck, but I want to confirm before I get rough with it. Literally every piece of the plastic including the headlights, seat ,and tail is broken or mangled so I'm chucking it all except for the upper fairing which I will repair. Yes those are wood screws.

 

[teazer]

I just drive them out with a pin punch, but you do have to be careful. It's very important to back up behind the pin properly. Sometimes I will make a back up plate with a finger or arm that fits up into where the pin is out of a piece of steel angle or plate that I can clamp securely in a bench vise. Drilling a hole in it for the pin to pass through will provide good support so you don't damage anything. Getting someone to hold the rack accurately on the back up while you tap out the pin(s) helps a lot.

That is exactly the right way to remove roll pins.

Nice slabbie project.

 

[doc_rot]

I got the bike titled so this project can proceed full steam!
I decided to do the fun part first to get me motivated and give direction to the whole thing.
Started sanding the fairing down to bare plastic, there had to be 1/4" of paint on this thing. once I had it stripped bare I realized this fairing has been repaired many times and was cracked everywhere. Coincidentally my dad recently finished building a wooden kayak and had a bunch of resin and fiberglass leftover that he offered to me, so I got creative. I made a crude jig and mounted the original fairing on it then filled in voids with clay. I also did a thin final layer over the whole thing inside and out to seal in the original fairing because I just kept finding new cracks.

I'm going to use a 4.5" Harley headlight with a custom bucket i made years ago and never used. Offset, endurance style; i rounded over the opposite side of the fairing as well to compliment the look.

Im going to try something I have never done and fabricate and aluminum rear cowl. Needs some bashing and trimming but its getting there. Total cost of the cowl with stick on seat will be about $40 depending on how much I spend on fasteners.

 

[doc_rot]

I traded some parts for a bunch of seals and gaskets, 6 pot calipers, a used 530 chain, fork seal driver, and a valve adjustment tool.

I had time to inspect the rear wheel. There was no spacer on the sprocket side except a steering neck lock nut that was doing absolutely nothing as the sprocket bolts were grinding on the swing-arm. I have a 10mm thick 20mm spacer that came in the box of parts that fits in the rear wheel dust seal perfectly. However, when the rear is assembled with that 10mm spacer there is not enough room on the other side for the remaining spacers. Is it possible the PO assembled the rear wheel without this spacer at some point and cranked on the axle hard enough that the swing arm bent and now the spacers wont fit? I got two wheels in the deal they appear to be identical, except with different disks. One is missing a bearing and the bearing spacer, and the other needs new bearings completely. Also the stepped spacer that goes in between the sprocket carrier and wheel is missing.

 

[Pete12]

Great job on the rear cowl. Is it all one piece, except for the seat base of course?

 

[canyoncarver]

That old rear sprocket tells a tale doesn't it?

 

[1fasgsxr]

Looks more like a saw blade...

 

[doc_rot]

Great job on the rear cowl. Is it all one piece, except for the seat base of course?

Im just getting started on the rear cowl, I only bent up one side so far. The camera makes it look more complete than it is. ultimately I think it will be 5 pieces total.