Yamaha SR500 FAQ
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Yamaha SR500 FAQ

Maintainer: Alan Fleming (alanf@dorje.com)
Version: 1.7
Date: 5/11/98

1) What engine did Yamaha put in the SR500? Is it the same engine that was in the SRX-600 or the XTs?

Mark M. Hatten:
It's basically a TT/XT 500 motor, with, as I recall, a few changes like larger valves, different carb & pipe, ignition, etc. The 600 Yamaha motor is quite different, with a 4-valve head, counterbalancer, twin carbs, etc.

Gideon van Zyl:
Same engine as in XT, but with electronic ignition. The gearing also felt different and the power characteristics also - might have used different cams

Bill Kitchin:
Yamaha SR500 engine is different from the XT/TT version. SR engine has larger intake valve, CD ignition and a bigger flywheel on the 78-79 motors. 80-81 engines used the XT smaller flywheel. SR engine is all aluminum unlike XT/TT. SR has bigger fins on cyl head & cyl as did LATE model XT's. SR has a stronger piston and beefed-up cluth area. Most of these items were added to the XT around the 80 model year as Yamaha started to make SR/XT engines the same as a cost savings move

George Sandoval:
The XT. TT and SR are basically the same. The SR does have larger intake valve but those can be matched if you have an earlier model of the XT, TT or even SR. You can buy the seats and valves, and have someone or yourself install them. There are other mods made to the earlier engines at the factory that can be duplicated; additional thrust washers, and misc parts to get the two motors on par. I've had someone tell me certain parts on one of the models are made out of magnesium.

2) Are other parts on the bike from other bikes? (forks, swing arm, instruments, etc?)

Mark M. Hatten:
The bike is basically an XT with a bit larger frame tubes, cast wheels, etc.
I'm sure a few of the components interchange.

Norm Lastovica:
There may be some interchangeability of front ends and swingarms with RD350's, 400's or even FZ600s. I've heard that a 750 Seca front end will bolt up to a TT/XT500 - if true, it should work on an SR500. Wire wheels shouldn't be too hard to fix up.

Jim Colbert:
Some XS-650 front end pieces are interchangeable, too. A dual front brake conversion can be done using pieces from an XS-650 (so I'm told); you can also take the wire wheel from an XS-650 and bolt it right on.
Tank, side panels and that thing on the seat are unique to the model here in the states, but there are 400cc models cosmetically identical sold in Japan and in Europe.

John Emmons:
Here's a simple tip that I discovered while working on 79 SR, I needed a new turnsignal flasher, new over $40.00 if available, went to an auto parts store and was shocked to find the same damn flasher for less than $10.00! Made me wonder if there are any other parts interchangeability ideas out there.

3) What are the most common modifcations for the street? Are there any fork, brake and/or wheels that are bolt on options? Are there any companies in the US or elsewhere that sell hop-ups, additions, etc?

Mark M. Hatten:
The most bang from the buck is what is known as "The Minton Mods". Joe Minton did an article for Motorcyclist Magazine several years back.
Motorwise, he bolted on a Kerker headpipe to the stock muffler, dropped a K&N filter into the stock airbox, upped the mainjet, shimmed the needle, and filed the slide down a bit. He picked up several horsepower and made the bike more rideable. My SR has this setup, but it has a White Bros./Supertrapp pipe. You can go to bigger carbs, hot cams, hi-comp pistons, etc., and pick up some more horses, but you reach diminishing returns very quickly. Plus, don't forget you have to kickstart the beast! In the chassis department, he slipped on Dunlop 391 (this was several years ago, remember), put in Progressive front springs and 20 wt oil, slightly longer rear shocks (S&W, I think), had the front disc drilled, ran Ferodo pads and stainless lines and a fork brace, along with lower handlebars.
My bike has 591s, longer preload spacers, lower bars and a bar end mirror, stock rear shocks, stock pads. It only has about 8,000 miles, and I really don't ride it that much anymore. I may pop for Progressive springs and rear shocks if I have an excess of money laying about. I've seen several SRs with wire wheels, usually with an XS650 front hub and a TT/XT rear hub laced to aluminum rims. Dual discs can be accomplished with an extra SR rotor (wheel already is drilled and tapped for it) and a right side caliper from an XS400. Most I've seen run the stock master cylinder.

White Brothers -- Pipes, carbs, cams, pistons, etc.
Denny Berg's Time Machine/Thumper Stuff -- (714) 841-7788. Cool stuff, neat pipes, temp. gauges, motor and chassis stuff. Denny really knows his stuff (used to be White Bros. R&D guy, and you've probably seen his bikes in Cycle and Motorcyclist), and is great to work with. I'd recommend him for anything regarding your SR (he also does SRX, GB, and FT stuff, but the SR seems to be his focal point.
Edco -- (707) 763-7519. Motor stuff, cams, pistons, etc, and machine work.
The Garage Company -- (310) 821-1793. The SR is still sold overseas, and is quite popular in Japan. There is a lot of OEM and other high-quality goods available on the Japanese market (billet rearsets, alloy tanks, etc.) that these guys can import. Be forewarned, it is incredibly expensive.

Gideon van Zyl:
Wiseco 600 piston kit

David Wood:
Making it lighter: Change the stock steel wheels for wire wheels, RD350 wheels should fit. Exchange the steel fenders for plastic fenders.
Replace the battery with either a "battery eliminator" or a lightweight gel acid battery. If you can find a Calfab or similar aluminum swingarm from an RD 400- that might fit. (The SR and RD frames look very similar, almost excactly the same except for motor mounts but I haven't actually tried an RD400 swintarm or SR350 wheels on an SR500). It may be hard to find any Calfab parts since they're out of business. Make it faster: White Brothers offers a big bore piston of 90mm, cams, pipes, carbs etc.

Norm Lastovica:
An sr500 fits the AHRMA SOS F2 (sound of singles, formula 2) class.
there is a fair ammount of stuff still available for the TT/XT/SR 500 motor.
since this is a 2 valve motor, you can go up to 610cc. however, you'll most likely want to start with either the stock bore and high compression piston (both weisco and venolia make 'em). you could also go to about 535cc with a weisco big bore piston. megacycle is a good place for a cam. you'll also want to bolt on a new intake manifold (try white brothers) and carb (I use a 40mm dell orto, you could use a 40mm or 44mm mikuni with good results as well). and, have a quality port and valve job done. I'd recommend jay wright at bare bones machine in colorado (719.687.0431) for some good horse power. I also removed the entire kick starter mechanism (bump start only now). other than that, the motor from the base on down is basically stock.
I build a new crank every other season (with a new rod and pin).

Rodent:
Currently my SR is stock except for slightly larger tires and 1" taller heavier shocks in the rear. The forks have 10 wt oil and 0.5" preload spacers. I am about half-way though adding a second brake to the front I scrounged a rotor and caliper from a 650 Special and master cylinder from an XS1100. I kept the stock carb and stock jetting but installed a Harley-style muffler -- can you say loud? I bought it for $185 with a bent valve and wound up doing a complete top-end job on it complete with new valves and rings. It runs really strong although it does use some oil -- I am starting to suspect the fellow who fitted the rings may have been a bit sloppy. I recently discovered the previous owner put a 1-tooth larger countershaft sprocket on it, which explains why it won't cruise in town in 5th gear. At any rate it will run all day at 70 -- I have had several 250+ mile days with no problems. I plan to finish up the bike with a small cafe fairing and some polishing on the forks and engine cases. A new clutch and a gunfighter-style seat will be in the works also.

G.ROSS:
I have had my SR 500 for about 17 or 18 years now. It performs well for a nearly stock engine pulling in excess of 180 kmh in top gear. There may be an upcoming article on my bike in Classic Bike. I have modified it from standard in the following ways:

Fitted a TZ 350A fuel tank,
TZ 350 G seat, stretched in the base a little to circumvent having to fit a rear mudguard,
Ducati 750 SS fairing,
Magura clipons,
Rod Tingate Racing megaphone exhaust and rearsets, (Australia),
Suzuki GT 750 J front brake and 18" Akront rim,
Yamaha TX 750 rear wheel, modified to accept 17mm axle, gearing 14 - 34,
Wiseco 88.5mm piston,
38 mm mikuni from TZ 350,
Got rid of battery and replaced it with a 100 volt capacitor, plus a whole host of other minor changes.

Rob Whittlestone:
In February, '97 I bought a second-hand 1994 model SR500 ("48T") with only 900 km (565 miles) on the clock. I had admired the SR500 for a while before deciding to take the plunge and was lucky enough to find this bargain. The current Swiss model makes 24 PS DIN (that's horsepower) and has spoked wheels and drum brakes fore and aft. In Switzerland bikes are sold restricted (to meet emission laws). The first action the owner undertakes is to de-restrict them. This is also usually horrendously expensive here. Since February I have modified the bike a bit and covered 3300 km. I have quite a few sources of interesting bits for the SR:
Wunderlich GmbH
Tel. +49 2641 979 00
Fax +49 2641 979 033
They have a large catalogue for SR & XT bits. From them I have bought and fitted:

I saw them in a magazine and wrote to them, they had a handlebar-mounted choke knob. I never got a reply and have never managed to speak to them on the 'phone. But they still advertise in a German magazine, curiously enough.

Upcoming modifications may include...
o Polished aluminium tank (I located the company but don't have the details on me today - they have several that look like Norton etc.) o Single race seat (preferably also in polished aluminium) o Remove passenger foot-rests (but then I need a solution for the muffler mounting, since muffler nowadays bolted to RH passenger footrest bracket) o I will maybe lower the headlight and clocks (clocks look too high, somehow) o Maybe clip-ons o Maybe rear-sets (if clip-ons) o "Hella" brand rear light - this is a beautifully classic round-shaped light on black or chrome base perfect for mounting on a mudguard (fender).
o I will maybe remove or change the indicators (too big, too orange and too Japanese!)

Oddments department ...
o My main concern is to reduce the weight (especially by removing things) before I start making expensive (irreversible) engine mods.
o I want adjustable fork caps but Denny Berg has sold out and says he can't get any more. Got any ideas where I should look? o I have seen conflicting values for maintenance intervals - older maintenance guides (Yamaha workshop manual, Haynes manual, German-language manual) say every 3000 km - the 1994 model owner's handbook says every 6000 km.

James Nelson:
I have a 19080 SR500 I got as a basket. During the course of its rebirth, I changed a number of things mechanically. My Yamaha dealer had this nifty auxiliary oil line that routes oil from the pump to the exhaust valve area, instead of the stock metal pipe that routes it near the intake valve. I think Denny Berg sell this; Dennis Kirk or White Bros. used to.
I also put dual disc brakes up front, the new rotor coming from the motorcycle boneyard of a friend of mine's. After drilling both discs (see Minton article) I attached them only to discover that the stock master cylinder DOES NOT have enough power to handle two discs. $100 got me a "brand new" master cylinder originally meant for an XS1100. Works fine. Hard living at the hands of the previous owner required the replacement of the piston, cam, cam followers, and various other top-end bits due to lack of oil. K591 tires run on stock rims; new handlebars; new chain & sprockets (stock rear, 1 tooth bigger countershaft). To be legal, turn signals were added where there were none before. About all that's left is paint, the stock maroon paint looks pretty good when it's wet, but lousy the rest of the time. The bike is a blast to ride, even though it doesn't have much power. It'll leave bigger, heavier bikes in the dust coming down the tight, twisty canyon roads here in Utah. It's not much fun on the freeway, due to the lack of power and light weight (trucks and strong crosswinds will just about blow you off the road! No exaggeration!!!) I'll probably keep mine forever, mostly because I doubt anyone would want to pay the amount I have invested into it for a single cylinder, kick start motorcycle.

George Sandoval:
I 've seen a few bikes with aftermarket pipes, but I still feel the best option is to have someone make a pipe for you. Some welding a frame cutting will have to be done, but the benefits in groundclearance, look, and performance can't be beat for the price. Keep in mind you'll only have to make the header part of the pipe is you can find and use a can from another setup. I had Matsu at Escargot Engineering make mine. I think the best thing to do is find someone who builds engines, not justa mechanic if you go this route. Matsu tunes engines for Yoshimura. He used the can from one of their pipes and and bent the rest to fit my bike. At the same time we moved the rear passenger pegs up and out of the way to have the pipe peak out from underneath rather than on the side of the motor. It's spring loaded. Cool work. From here the rest is a Keihin 39mm smoothbore carb, 90mm Arais piston, WB2 cam and Oil Cooler from Earls supply. I'm currently building a race motor which will have more work done. I'll keep you posted on what works.

4) What about touring on the bike?

Mark M. Hatten:
The most bang from the buck is what is known as "The Minton Mods". Joe I've owned my SR since the mid-1980s, and for a while it was my only bike.
It's amazing what you can do when you set your mind to it. I find it comfortable for up to several hours, but you really need to avoid the Interstate. A 1 tooth larger C/S sprocket makes cruising at up to 65 mph pretty smooth, but it gets too busy above that. I've read about several people who do take long, even cross country trips on them. (But then again a Honda scooter finished the Iron Butt this year . . .)

Gideon van Zyl:
One-up fine - two-up I wouldn't recommend. Too little torque for maintaining a decent touring speed then. Mine was very light on fuel and quite comfortable as well as a good handler.

Jim Colbert:
The SR wouldn't be my first choice for touring, although it can certainly be done. I think of the SR more as a canyon carver than a tourer. With a national disregard for interstate speed limits, I'd try to stick to the backroads, which really is a nicer way to tour in my opinion anyway. The SR is light and succeptable to cross winds from maniac truck, RV, etc. drivers!

5) Any must-have accessories?

Mark M. Hatten:
A membership in the Four Stroke Singles National Owners Club, P.O. Box 1804, Hutchinson, KS 67504-1804. $20 bucks annually. Free T-Shirt, quarterly newsletter.

Gideon van Zyl:
Oil cooler

Jim Colbert:
First on my list is lower bars. K&N euro bars (in black chrome or chrome), Honda CB400F or some BMW bars are very similar; they're lower and narrower than stock but nowhere near as uncomfortable for extended riding as clip-ons. Although my own bike does not reflect it, I like the classic British look some have done: small flyscreen, polished alloy tank, wire wheels and a Manx style seat makes for a classic British look with Yamaha dependability. Improved top end oiling is a nice accessory that won't make any horsepower or look cool, but will extend the life of your engine. A fork brace provides some added front end stability, but for casual riding mostly just looks cool. Remember, this is 'just' a big single. You can pour an incredible ammount of time and money into trying to make it really fast and you CAN make it pretty fast, but you're probably still going to get blown off on the straights by the kid on the clapped-out EX 500. Out and out speed and performance just isn't what this bike is about. Or, you can do some simple mods to improve overall rideability without dramatically increasing the 'nastiness factor' i.e.
really hard to start, politically incorrect exhaust note, rough idle et al.
If you want a superbike, in my opinion, go buy one; there are a ton of super fast four-cylinder road rockets out there; quite a few are priced cheaper in similar condition than a clean used SR. Keep the SR for the twisties, for the canyon carving, for those beautiful summer moring commutes to work! More importantly, keep it on the road and get out and ride when you can! Finally, I saw in someone's reply they mentioned the Garage Company. You might want to consider whether you mention this or not in revised FAQ as I recall reading one of their posts to Thumper Message list asking to be removed as a resource as the focus of their business was being redefined, or something to that effect.

6) What magazine articles have been done on the bike?

Mark M. Hatten:
You can get an entire packet of all U.S. bike mag (and a few foreign) tests, hop-up articles (including the Joe Minton article) from FSSNOC (if you are a member) for a nominal fee.

Kevin Naser:
Yamaha SR500E - Cycle Magazine Road Test; April '78
Yamaha SR500G - Cycle Magazine Road Test; November '80
Yamaha SR500E Hop-Up Part 1 - By Gordon Jennings; Cycle Magazine; July '78
Yamaha SR500E Hop-Up Part 2 - By Gordon Jennings; Cycle Magazine; July '78
The Even Better TT500 - By Dave Boller; Cycle Magazine; June '77
Powroll's 605: The Horsepower Express - Cycle Magazine; June '77

KCombs8191:
Hey I noticed you had information on magazine articles about the sr 500.
There is an article in the june '98 issue of Iron Horse magazine that a friend of mine wrote about the sr's. My bike is in there and there are a few other nice custom sr's in there as well. I think it`s out on the news stands now. Not everything in the article is 100% accurate but it's good anyway. Check it out.

7) What is the going price for a good condition SR-500?

Alan Fleming:
This is an anti-answer. The value of bikes if so heavily relativistic that the price in one area of the country for a given bike has no bearing on the price for the same bike in another part of the country.
Ultimately, you need to determine local value by checking the classified section of your local newspaper, check with local shop and ask around.

8) What resources are available on the net?

Alan Fleming:
The THUMPER web page (http://www.thumperpage.com/index.html) is an excellant resource for meeting other Thumper owners. Likewise, the THUMPER mailing list (listproc@dorje.com) is home to many SR owners.
Also, anyone interested in roadracing their Thumper should subscribe to the roadracing mailing list (listproc@micapeak.com).

Chris Boone:
I just found the "Unofficial Yamaha SR500 Homepage" http://www.a-web.co.jp./~nosiro/ Based in Japan, it's by Masaya "HappyMan" Noshiro. Check it out, but prepare to get frustrated really fast.

Contributors:
 Mark M. Hatten (102136.3317@compuserve.com)
Gideon van Zyl (gideonvz@aztec.co.za)
David Wood (davewood@teleport.com)
Norm Lastovica (lastovica@hotrdb.enet.dec.com)
Rob Whittlestone (Rob.Whittlestone@ubs.com)
Bill Kitchin (droptop@amug.org)
Kevin Naser (lpiloto@radiks.net)
Rodent (weasel@dfw.net)
Jim Colbert (jcolb@barashgroup.com)
G.ROSS (stugle1@webfront.net.au)
Chris Boone (cboone@microsoft.com)
James Nelson (jnelson@nebonet.com)
KCombs8191 (KCombs8191@aol.com)
John Emmons (JOHNCYN@worldnet.att.net)
George Sandoval (punkkat@earthlink.net)
Alan Fleming (alanf@dorje.com)

Think Peace.
- Alan (alanf@dorje.com)
KotBBBB (1988 GSXR1100J) RaceBike (FT500)
DOD# 4210 PGP key available