DO THE TON

Blood Sweat Tears and Grease => Projects => Specials => Topic started by: doc_rot on Dec 12, 2017, 18:00:16

Title: Dirtbag Oil-Boiler
Post by: doc_rot on Dec 12, 2017, 18:00:16
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. Very strange. 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.
Title: Re: Dirbag Oil-Boiler
Post by: irk miller on Dec 12, 2017, 18:28:44
Those forks are so fun.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Dec 13, 2017, 03:19:42
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
Title: Re: Dirtbag Oil-Boiler
Post by: WhyNot on Dec 13, 2017, 06:38:31
Cool, I gotta watch.
Title: Re: Dirtbag Oil-Boiler
Post by: 1fasgsxr on Dec 13, 2017, 10:26:01
I am so watching this one !!
Title: Re: Dirtbag Oil-Boiler
Post by: Popeye SXM on Dec 13, 2017, 10:37:22
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
Title: Re: Dirtbag Oil-Boiler
Post by: Maritime on Dec 13, 2017, 10:47:05
Sign me up. looks like fun
Title: Re: Dirtbag Oil-Boiler
Post by: The Limey on Dec 13, 2017, 17:00:55
Ooh, a Flexi Flier.  I've always had a soft spot for those old slabsides.  Good old fashioned hairy chested machines.  Watching with interest.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Dec 24, 2017, 06:34:17
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
Title: Re: Dirtbag Oil-Boiler
Post by: jpmobius on Dec 24, 2017, 11:07:45
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.
Title: Re: Dirtbag Oil-Boiler
Post by: Streetfighterkz on Dec 24, 2017, 11:12:52
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 Id have like it more if it was a 1100?

Later, Doug
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Dec 25, 2017, 03:15:12
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.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Dec 25, 2017, 05:14:11
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.
Title: Re: Dirtbag Oil-Boiler
Post by: teazer on Dec 25, 2017, 10:36:11
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.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jan 09, 2018, 04:42:11
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.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jan 09, 2018, 05:39:26
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.
Title: Re: Dirtbag Oil-Boiler
Post by: Pete12 on Jan 09, 2018, 07:06:19
Great job on the rear cowl. Is it all one piece, except for the seat base of course?
Title: Re: Dirtbag Oil-Boiler
Post by: canyoncarver on Jan 09, 2018, 12:47:53
That old rear sprocket tells a tale doesn't it?
Title: Re: Dirtbag Oil-Boiler
Post by: 1fasgsxr on Jan 09, 2018, 13:04:25
Looks more like a saw blade... :o
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jan 09, 2018, 17:11:55
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.
Title: Re: Dirtbag Oil-Boiler
Post by: canyoncarver on Apr 18, 2018, 17:43:17
Are you done yet?    ;)
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Apr 19, 2018, 00:46:35
Lol, masters thesis is priority uno right now. I'll be done in 3 weeks and then the bikes can get some real attention
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on May 16, 2018, 05:02:15
Well i finally have some time to work on this. I wanted to check the compression, but my compression tester died on the second cylinder, I did pull the valve cover to discover....shims? 86 should have adjuster screws.  I think its a 91-92 based off the Engine VIN. (R716-120195) I started pulling things off as literally everything on this bike needs attention. Its a rolling basket case.
Title: Re: Dirtbag Oil-Boiler
Post by: canyoncarver on May 16, 2018, 16:22:54
That's a better setup than the earlier screw adjuster type.  Those shims will be easy to measure and swap.   Cool!
Title: Re: Dirtbag Oil-Boiler
Post by: 1fasgsxr on May 16, 2018, 21:00:14
I still want one of this generation.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on May 16, 2018, 22:20:43
That's a better setup than the earlier screw adjuster type.  Those shims will be easy to measure and swap.   Cool!
Also good for an additional 16hp!