RG500 and RG400 production numbers

Model Location Qty Yr MFG Dates
RG500G exported 7340 86 4/85 - 3/86
RG500G exported 606 87 4/86 - 3/87
RG500CH exported 806 87 4/86 - 3/87
RG500G Japan 22 88 4/87 - 3/88
RG500CH exported 510 88 4/87 - 3/88
Total 9284

RG400 Japan 5002 86 4/85 - 3/86
RG400 Japan 2-UK 863 87 4/86 - 3/87
RG400H Japan 348 88 4/87 - 3/88
Total 6213

RG500G UK 902
RG500CH UK 240
RG400 UK 2
Total 1144

Frame numbers
RG500EWC - HM31A-100001~
RG500EW-W (Walter Wolf type 1) - HM31A-102691~
RG500EW-2W (Walter Wolf type 2) - HM31A-105061~
RG500CH - HM31A-105405~
RG500G (E34) - HM31B-100001~
RG500CH (E34) - HM31B-101646~
RG400EW - HK31A-100001~
RG400EW-2/2C - HK31A-106287~

Here is the information on RG500's sold in Canada:
870 RG500G's were sold by Suzuki Canada
The first VIN was 0G2100012, the last was 9G2100882
There were 99 Walter Wolf models imported and sold
The first VIN was 0G2100883 and the last one was 2G2100982

Here are the country/model codes:
00 Japan ("Home" or "domestic" market)
02 United Kingdom
03 United States
04 France
17 Zweden
18 Switzerland
21 Belgium
22 Germany
24 Australia and New Zealand
25 The Netherlands
28 Canada
33 California

34 Italy

37 Brazil

39 Austria

53 Spain

For a complete list of Suzuki country codes see

Suzuki Motorcycle Country Codes Identification

VIN codes on all motor vehicles sold in North America may be deciphered as follows using this RG500 VIN code as an example: JS1HM31A2G2100951: 
JS1HM31A2G2100951 = JS1 HM31A 2 G 2 100951

JS1 : Japan Suzuki

HM31A: vehicle type

2: check digit

G: model year F=85,G=86,H=87,J=88 

2: plant code

100951: ID number

Earlier numbers, like 001 through 005 or so are usually destroyed, as they are "Production Prototypes"

Ex Noriyuki Haga Suzuki RG400

Ex Noryuki Haga RG400. This Suzuki RG 400 is the Asian version of the RG 500 Gamma. This model was sold in Japan and only a few arrived in Europe. The 1988 RG 400 is the last 4 cylinder two-stroke with rotary distribution produced by Suzuki and equipped with a reinforced gearbox (1987/88). The here presented model is entirely original (unlike the RG 500, the RG400 was factory delivered without the lower fairing). The bike has run 18.746 km from new. This bike has a particular history which is of high value for a collector. It was bought by the famous Japanese World Championship rider, Noriyuki Haga, who had a residence in Italy. Haga imported the bike to Italy.
Year: 1988
Frame N.: HK31A-108374
For more pics see 
Ex Noriyuki Haga RG400

This bike was sold by
Classic Motorbike Collection 

Differences between the RG400 and the RG500

When I was cleaning my mailbox I found some great information about the differences between the RG400 and the RG500, so here it is.
1. Carb slide needle and main jetting: 400 = #135 , 500 = #120.

2. Clutch: the 400 has some friction disks less (1 or 2, I’m not sure). See if your clutch will work OK so you may leave it as it is.

3. External sprockets and chain, 400 = 15 front /41 rear, 525 chain, 500 = 16/40, 530.

4. 400 pipes have only thiner stingers, all the bodies are the same.

5. Cylinder, piston: 400= 50mm 500=56mm 400 has 5 intake ports, 500 has 7 intake ports but smaller (but 400′s port in total I think give better flow – i.e. less divided area). External lower sleeve diameter 400=60mm , 500=66mm you need to rebore the upper crankcase. But I’m not sure if you can rebore your 400 cylinder sleeves to reach 56mm so you won’t need any crankcase machining (and won’t need to buy a 500 cylinder set). Remember the 400′s cyls may give a better intake port flow.

6. Heads diameter accordingly are of: 400=50mm , 500=56mm.

7. Conrods are the same, only its lower bearing consists of some more (1 or 2, I’m not sure) needles so they are closer each other. You may not bother splitting your cases and keep your 400′s bearings though if you go arround the stock 500 horse power (no much more).

8. Some small difference in the front brake rotors. 400′s are no “floating” type.

9. The rotary valves have different base, the 400′s is thinner and lighter so keep your 400.

Walter Wolf RG500 and 400

Walter Wolf was an Austrian born and later Canadian business man who made his fortune in the oil business. He happened to be a giant motorsport lover and funded an F1 team. He must have been a special character as in 1975 after having purchased a Lamborghini Countach, he claimed this wasn’t fast enough and asked for a special version of it with a more powerful engine. And so, in addition to the special edition Suzuki RG500 and 400, there are apparently 5 ultra rare Lambos named WW around the world as well. The RG500 walter Wolf Special - a very limited, very distinctive edition of the 500cc Suzuki machine that has won seven championships in world-class Grand Prix racing. That racing heritage continued in 1986 with the Walter Wolf sponsored RG500 winning the Canadian National Pro & Amateur 600 Production Championships. The full power Walter Wolf RG500 Gamma of which only 99 were produced, were only exported to Canada. No other venue (including the Japan domestic market) was to ever receive the real deal 95 hp Wolf. Canada WW's are distinguished by a dedicated series of VIN's beginning with the last three digits of 883 and ending with 982. Also the Canadian bikes did not have the WW logo on the gauges nor the WW key that Japanese Wolf's had.
(Update 20-04-2016, I received an email from Bob Truelson a well known name in the RG500 community and he told me that some of the Canadian bikes also had the WW logo in the gauges)
Of the 99 production Canada WW's, a surprising number went to Mexico where Walter Wolf was a big name in F1 auto racing circles. Perhaps as many as 30 of the new bikes were shipped there to very appreciative owners, never to be seen again north of the border. The Japanese market had the Walter Wolf RG400 and RG500 in 1986 with colors like the Canadian model and in another black and red scheme and with different clocks. For the Singapore market there was a WW in a grey color. In 1987 the Japanese market only Walter Wolfs came in a new color scheme with the RG400 having Walter Wolf Racing on the belly pan and the RG500 with "500" on the belly pan. These colors are also known as the Mizutani replica colors, Mazaru Mizutani is a former Japanese 500cc champion and was sponsored by Walter Wolf Racing. This last model is very rare.
For more pics see
Walter Wolf RG500 and 400