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!
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on May 22, 2018, 07:29:08
I have met a large debacle. I initially wasn't going to pull the motor, but the previous owner resprayed the it at one time and did a piss poor job of it. There is over-spray all over the frame and swing-arm, and the paint on the motor is flaking off badly. I pulled the engine to clean the frame properly and repaint the motor but while doing so I discovered one of the engine mount lugs on the frame has sheared off.

Im feeling like i should cut and run. There's too much ham-fisted stupid shit going on here. Its all parted out and ready to go, I could probably recoup my cost and then some based off the unusual parts.
Or.....
I could continue on. I have a friend who is more than qualified to repair this frame, and he'll probably do it for a 6 pack. Hell, I may even have him do some frame bracing while he's at it.

My concern is i'm gonna ride it, not like it, and want to sell it after putting a bunch of hard work into it.(been there done that) What is one of these worth if it was clean and everything had been gone through, with almost no original parts? $2000? (Bay area prices)

Title: Re: Dirtbag Oil-Boiler
Post by: Popeye SXM on May 22, 2018, 10:50:39
I feel your pain. it is decision time.... Looks like a lot of work to make nice, how healthy is the motor. Judging by the rest of the bike probably not good
Title: Re: Dirtbag Oil-Boiler
Post by: teazer on May 22, 2018, 11:49:40
As I see it, not much is stock - motor is  a later Slingshot, rear wheel isn't stock, front wheel is a Dymag - OMG that wheel is worth a fortune - no it's not - I will swap it for a something more suitable at no cost to you.......

Any sign that the bike had been raced?  Bolts drilled for lockwire etc? Or is it just a mongrel?

Point is that it will never be 100% original but could be a fun bike and yes it will take time to rebuild and if you don't like it, someone will get a great bike to ride.  I cannot tell you how many bikes I have built over the years and sold almost immediately because I already lost interest in them.  You do not want to become me, but this one could be a fun project to build and resurrect.

I would plow on on an build it as a endurance racer look or other slightly customized look and get your cash back and have some fun building an updated slabbie maybe with newer USD forks.
Title: Re: Dirtbag Oil-Boiler
Post by: canyoncarver on May 22, 2018, 12:59:34
Build it quick as a low buck racer, fix the frame, clean it up a little, bolt it back together and get it running.   You can minimize your time and $ investment and still come out with a bike that will be alot of fun to ride and should still sell easily enough if it's not your thing in the end.    My .02.  fwiw
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on May 22, 2018, 17:41:37
I just got off the phone with my buddy that will do the welding. He love the early GSXRs so maybe not the most un-biased opinion. he has convinced me to build it and do some frame bracing, while the repair is being done. I'm now looking for a junk frame to cut up and brace this frame with like the factory racers
Title: Re: Dirtbag Oil-Boiler
Post by: teazer on May 22, 2018, 20:02:01
(https://i0.wp.com/tontonbecane.com/wp-content/uploads/2016/11/suzuki-yoshimura-ama-superbike-1986.jpg)

(http://2.bp.blogspot.com/-Bu-xDSQDoNY/Viynh_VGbpI/AAAAAAAADj0/NHAAr9r8H-I/s1600/suzuki-gsxr-1100-1986-yoshimura-4.jpg)

(https://www.motorcyclistonline.com/sites/motorcyclistonline.com/files/styles/1000_1x_/public/images/2016/09/tate-casey-gsxr.jpg?itok=GHQEqQm1&fc=50,50)
Title: Re: Dirtbag Oil-Boiler
Post by: irk miller on May 22, 2018, 20:27:12
Or a good frame so you can use this junk frame for bracing.    ;)
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on May 22, 2018, 20:36:02
I dunno if i'm going to go this crazy but i'm entertaining the idea.
Title: Re: Dirtbag Oil-Boiler
Post by: hooligan998 on May 23, 2018, 01:08:40
Love these old slab sides.  Following.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jun 05, 2018, 06:39:12
Here is the straw that broke the Gixxers back. Definitely wont be able to keep it under $1000 if i decide to proceed. Dirtbag's part out bikes, they don't rebuild motors. gonna think on it a while before i decide what to do.
Title: Re: Dirtbag Oil-Boiler
Post by: canyoncarver on Jun 05, 2018, 12:38:13
Buggers, well at least there isn't a hole in it.   ;)
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jul 21, 2018, 06:05:06
Well after thinking about it for a bit, I have decided to proceed. I'm too excited by the potential end result. There's no way I'm going to make my purposed $1000 budget, but if i can keep it under $2000 id be happy. I have started looking for a deal on a 1100 engine, but no luck yet.

I rebuilt the forks, and measured the spring which is about 18". the rebound spring is about 3.5". I'm pretty sure it has a lowering spring kit as the stock spring is supposed to be about 15". this explains why it seemed so low when i picked it up.

wondering if this is a this a desirable mod for this bike or was this setup for a short person?
Title: Re: Dirtbag Oil-Boiler
Post by: crazypj on Jul 21, 2018, 14:47:30
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
Do the Bandit wheels and forks, 43mm are way better than the 37mm and rims are wider. That's probably my favorite motor ever but not so much the frame (600/750 Katana is 'better' frame,stiffer and more rigid) The alternators from any of the 'oil boilers' will fit but you need correct drive gear to match gear in engine. Later ones had a better rectifier/regulator but there isn't really anything wrong with early model. . Over charging is more common than undercharging (battery boils dry) It's caused by old connectors supplying wrong voltage to reg. Easiest fix is cut power to alternator and fit a relay direct from battery so you know it's getting battery voltage direct. My bike dropped from 17.4v to 14.2 after doing it (full field at idle is around 17v)
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jul 21, 2018, 14:59:49
The forks are 41mm on this bike, and i love the ridiculous adjuster on the fork leg so Im going to try to stay with them. After talking to the guys at Dymag they didn't recommend running a magnesium wheel of this vintage on the street. So i sold it to a dude in Japan for a tidy profit that will go back into this build. I picked up the bandit wheels from my buddy in a trade. They're gonna take some work to fit.
Title: Re: Dirtbag Oil-Boiler
Post by: crazypj on Jul 21, 2018, 15:56:06
That's a better setup than the earlier screw adjuster type.  Those shims will be easy to measure and swap.   Cool!
Rumor has it that Suzuki redesigned top end on Pop's Yoshimura's request. You get an extra 500~1000 rpm with the lighter rocker and shim arrangement Had a major issue when valve lift got to high, rocker arm hit edge of ship and spat it out. Only the 600 and 750 ever had -shims, I havent tried retro fitting to 11/1200 head but I have some parts to try. You could fit 11/1200 top end to 750 but transmission would be weak point (1100 breaks stock 5 speed, don't think 6 would last long with extra power and torque?)
1200 Bandit should have 43mm forks? I sold the set I had, they are now on a GS1100 (posted pic somewhere?) Oh, I'm pretty sure I have some 0.5mm OS pistons for 750 motor. Can't remember where I stashed them at present though? (was going to rebuild a 600 motor I have with a 750 top end on it)
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Jul 21, 2018, 20:14:06
If i'm going to rebuild a motor for this bike its gonna be the 1100, or possibly a bandit 1200 motor.
Title: Re: Dirtbag Oil-Boiler
Post by: crazypj on Jul 22, 2018, 01:38:19
7-11  8)
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Aug 17, 2018, 03:14:44
front end sorted out. Took a bit more machining than I hoped for but it all came together. I used the bandit wheels, ebc rotors and original calipers. The rotors needed a bigger PCD, and the ID opened up to fit the bandit wheels. The calipers needed a small washer to center them on the disk, and since I was missing a wheel spacer, I decided to make them all from scratch and delete the speedo drive while I was at it.
Title: Re: Dirtbag Oil-Boiler
Post by: advCo on Aug 17, 2018, 09:23:15
Not sure how I missed this. Following along. One of these came up for sale locally not too long ago and I have to say I was very tempted.
Title: Re: Dirtbag Oil-Boiler
Post by: JustinLonghorn on Aug 17, 2018, 09:26:16
I can dig it.
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Nov 03, 2018, 05:36:06
the frame has been boxed in and braced. The broken motor mount is repaired. This frame is a proprietary alloy that is basically 7005. I used 6061 for the braces and 5556 filler rod. The castings were difficult to weld, twice I had something in the casting explode and pop molten aluminum out at me. I want to brace the swingarm as well, but I'm going to wait till its on the road so I can do a comparison. I painted the triple trees with gun kote and installed new bearings. I went through all the bearings in the rear end and cleaned them out and packed with new grease. Its rolling again, sitting on Metzler Sportec M3, which i spooned on sweating it out on the garage floor(I'm a Luddite when it comes to tire machines). Never ridden a metzler tire before, excited to try them out. I'm still on the hunt for an engine.
Title: Re: Dirtbag Oil-Boiler
Post by: Luugo86 on Nov 03, 2018, 17:29:14
Sexy welds
Title: Re: Dirtbag Oil-Boiler
Post by: pidjones on Nov 03, 2018, 21:32:10
I know nothing about aluminum welding (very little about steel welding). But, as a GoldWing rider, welding extrusions to castings all with different alloys is a bit scary. It took Honda until 2005 (building 2006 models) to finally get theirs right.
Title: Re: Dirtbag Oil-Boiler
Post by: canyoncarver on Nov 04, 2018, 13:55:08
Really nice bracing work.  I'm glad you haven't ditched this project. 
Title: Re: Dirtbag Oil-Boiler
Post by: doc_rot on Nov 04, 2018, 15:30:25
thanks guys. I'm excited for this project to come together.
Title: Re: Dirtbag Oil-Boiler
Post by: crazypj on Nov 05, 2018, 02:12:58
I forgot to answer your question about swing arm being bent if sprocket carrier bearing spacer is left out. Not only likely but common. On later GSXR the welds can/will crack, particularly 2008~2010 which had pretty poor welds . Early models were welded up properly so you can heat swing arm and push it back into shape (only heat bent side near pivot end and use scissor jack with wood block) I had to do one or two at dealer after people got cheap tyre change and spacer 'went missing'. Usually the sprocket carrier bearing was shot as well with wheel 'floating'