OzVMX Forum

Marque Remarks => Suzuki => Topic started by: ozyditcher on September 10, 2010, 03:32:11 pm

Title: DR400 mods
Post by: ozyditcher on September 10, 2010, 03:32:11 pm
Bulding a DRM400, does anyone know if someone makes a rev box or cut a wire?
Title: Re: DR400 mods
Post by: oldfart on September 10, 2010, 04:16:49 pm
Not too sure what you mean by "cut a wire" ???   I find short shifting them into another gear works better than reving the shit out it.
Title: Re: DR400 mods
Post by: LWC82PE on September 10, 2010, 06:30:22 pm
Do you mean a CDI unit ?

Anyway for all things DRM's Olfart is your guy to speak to, plus check out these threads

http://ozvmx.com/community/index.php?topic=4376.0

http://ozvmx.com/community/index.php?topic=943.0

This place in NZ makes CDI units for TT/XT yamahas so they might be able to do them for the DR. Keep in mind you can only do so much with an analog system.

http://cgi.ebay.com.au/YAMAHA-XT400-XT-400-XT550-XT-550-XT600-XT-600-IGNITION-/200516552054?pt=AU_Motorcycle_Parts_Accessories&hash=item2eafb7c576

http://www.erd.co.nz
Title: Re: DR400 mods
Post by: ozyditcher on September 11, 2010, 04:45:03 pm
Thanks guys for all the info, yes i was talking about the CDI. Im a honda guy, i  got the bike 3weeks ago and raced it stock :o  with a full gate of 250 and 500 two strokes , one Mike Bell.  I see Tom White every weekend, il ask him and let you know.
Title: Re: DR400 mods
Post by: evo550 on September 11, 2010, 06:23:35 pm
Best thing you can do to those old 4 strokes is remove a counter balancer if they have one. Throttle response is drastically improved and they rev out much quicker. Only a slight increase in vibration at idle.
Don't know if suzuki fitted one to the DR's, but worth checking out.
Title: Re: DR400 mods
Post by: Curly3 on September 11, 2010, 06:44:28 pm
Thanks EVO, I've got a DR500 that I want to REV a bit harder and they have 2 counterbalance shafts,not to mention the benifit of the weight loss.
I'm not sure about the 400 engine.
Steve
Title: Re: DR400 mods
Post by: oldfart on September 11, 2010, 07:12:08 pm
Dr/Sp  400 has no internal counter balance.....primary side drives clutch cam chain and oil pump - opposite side has flywheel .
Title: Re: DR400 mods
Post by: Curly3 on September 11, 2010, 07:54:38 pm
The balance shafts on the 500 both run parallel to the crank, one just in front of and one just behind, fitted to counteract the throw of the flywheel.
I'm definitely no expert and would love to hear from someone who has removed them.
Sorry for hijack.
Title: Re: DR400 mods
Post by: TT5 Matt on September 11, 2010, 10:51:01 pm
if you want your 400 to rev out quicker fix a button rotor out of a chinese 140 and use the cdi charge coil to power up the 400 cdi box,also fix heavier valve springs and a better cam
Title: Re: DR400 mods
Post by: YUMASTEPSIDE on September 12, 2010, 07:19:39 am
I too would like to know about the balancer removal on the 500's  ;D ???

                              Roger
Title: Re: DR400 mods
Post by: oldfart on September 12, 2010, 04:21:26 pm
It's not hard  . Remove paddles along with drive chain on LHS of motor . Be warned motor will viabrates up thru handle bars making you hands go numb.
"DR 500"   race's up here in sunny QLd with  balances removed   ;)    I've tried it on my test mule and put them back  :)
Title: Re: DR400 mods
Post by: YUMASTEPSIDE on September 12, 2010, 04:40:04 pm
........so that would be a big DON'T DO IT then   ;D ;D

                        Roger
Title: Re: DR400 mods
Post by: evo550 on September 12, 2010, 05:23:02 pm
I took counterbalancer out of a xt550 and only noticed slight increase in vibration at idle. My top triple clamp had rubber mounted handlebar clamps, that may have made a difference, not sure how suzi bars mount.
Title: Re: DR400 mods
Post by: Curly3 on September 12, 2010, 06:19:23 pm
It would be interesting to know if the vibration is only noticable at idle and reduces as peak revs build?
Title: Re: DR400 mods
Post by: DR500 on September 12, 2010, 07:54:33 pm
Too remove them completely you have to strip motor apart.If you just want to try them disconnected,just remove chain.I ,as old fart said have been racing my Dr500 for a few years with them removed.Not notice that much of a vibration difference.It wil rev harder and faster, but these old things really don't have to rev that hard,just change gear!
Title: Re: DR400 mods
Post by: GMC on September 13, 2010, 10:05:14 am
I have heard a couple of reports of shock shafts snapping because of the extra vibrations of having the balancers removed.
One was on an XT 600 that was ridden on the road, snapped the shaft a couple of times.
Another I think was a Husky 610 in a road bike frame that was road raced, it also snapped the shock shaft a couiple of times.
Title: Re: DR400 mods
Post by: YUMASTEPSIDE on September 14, 2010, 06:43:05 am
to remove or not to remove- that is the question.
whether it is nobler in the mind to suffer the vibration of the handlebars or to bear the slowness of accelereation.......sorry, I digress !!

.........so, remove or not ??    ;D ;D ;D

                        Roger
Title: Re: DR400 mods
Post by: mick25 on September 14, 2010, 07:12:38 pm
I have a dr500 and while the gear box was striped and getting rebuit, i had the same idea to remove all the moving bits of the balancer it all came to around three and half kgs in weight so its a fair bit of weight, but when i asked my local bike mechcanic he talked me out of removing them ,and i throught any way they were put there for a reason :P ,
when i had my gear box apart the gear dog from second gear was broken off,second and forth gears have smaller dogs than others ,TT500 ones are twice the size... 8)
I dont no how mine broke it might of been a week make or push starting (SOME THING I DONT LIKE DOING ON 4 stokes because of extra strees on these parts) or persons rough usage >:(
 IT made me a bit worryed  ???
because i use second gear on race starts, but saying all this i havent any probs for the last 4 years thats my 2 bobs worth :D
Title: Re: DR400 mods
Post by: cloggy on September 21, 2010, 05:33:13 pm
 If you see Tom White every weekend, ask him if he's got the jetting specs for the 36 Mikuni he used to sell for this model. He was kind enough to send it to me decades ago, and I've lost it.
The key to making these old motors go is to get more torque out of them by modding intake exhaust and getting different cams [cams make a difference on the DR but although Mega Cycle have the profiles and and R & D have the springs, the keepers are no longer available from R & D]  ie getting more power per rev, not more revs
 Also they're a bit slack on the front end. They tightend the head angle by 1 degree back in the day, not that I've done this. However I have run short front forks and long rear shocks and it never got anywhere near unstable
 The back wheel is real heavy. You lose more weight changing that than adding an ally swing arm.
There was a DR at Farleigh this weekend. It was running 81 + RM rear wheel assembly in a PE or RM square swingarm
 [The UK is pretty informal as to what one can use on twinshock compared to the USA or OZ]
Problem is you end up with a very high seat and a very short overworked shock. The DR frame has the shock mounts set further rearward than the RM. You really need a custom shock to fix that. That could cost as much as the rest of the bike! Or just relocate the arm shock mounts.
 Best ally arm for these is a KLX250 or a 78 RMC round ally arm. The latter you have to weld up with ally tube inserts inside the ends of the swing arm pivot {+ slightly wider] That gets rid of the weakness on that arm and lets you use all the DR pivot pin gubbins. They aren't any longer than the standard arm so it's a lot of cost  for just a bit of weight as you have to use slightly shorter shocks. If you haven't yet got decent shocks then it makes more sense. Stock arm needs a 16.5 " shock with  a 4.5" stroke
The RM needs a 400mm arm. I think the KLX needs much the same.
There is possibly one more option. The later DR500 is supposed to use an ally arm dimensionally identical to the 400's steel arm. Apparently they originally designed the 400 arm in ally but made it in steel due to cost. That is your best bet if you're in the USA. UK never got the 500. Another recession saw to that.

 
Title: Re: DR400 mods
Post by: oldfart on September 21, 2010, 06:04:40 pm
Cloggy, Most of the USA 1983 DR 500 came with alloy rear swing arms - and yes they are a straight bolt up fit.
I have had a great run with a pair of piggy back shocks off the same model bike ......spring rates - travel - and length are spot on.
Title: Re: DR400 mods
Post by: cloggy on September 22, 2010, 05:17:19 am
 There has always been some confusion as to whether 500s came with ally arms or no. Thanks for that. Did the SP500 have just the steel arm? I have a feeling that the SP may have had a pretty much identical frame, engine and swingarm, possibly wheels too.
Do you mean that you're running the 500 arm in the 400 frame?
There is a lot of commonality between the 400 and 500 and I assumed the 500 arm to be dimensionally identical
 I'm running Ohlins  16.5" shocks on one road going DR. It came as a rolling chassis with them. They are off the Armstrong/Harley 500/350 Rotax 4stroke Three ex army guys were racing them at the Farleigh Castle international meet last weekend. They were far from last too!
Title: Re: DR400 mods
Post by: EML on September 22, 2010, 02:22:38 pm
The 400 model was suposed to be identicle to the 500 except the Japonese had a 400cc upper limit for that range of bikes.
If you look across the range the home market had 400s in every thing i.e. XT/TT XL/XR DR/SP etc...
It was their way of limiting riders though how you can get hurt on a 500 but not a 400 is a question to be asked???
Title: Re: DR400 mods
Post by: cloggy on September 22, 2010, 07:13:18 pm
 Yamaha did a 400 version of the 550 and the 500 which are totally different bikes. I hadn't heard that Suzuki had done the same with the 500 4 valve, though it makes sense.

 There's a 400cc Test limit in Japan. To ride bigger bikes one has to take a much more involved test/racket for [ex policeman] instructors. If you don't take loads of lessons you are failed by their mates the testers.
 
The bike that predated the 500 was initially the 370 SP/DR. That was beefed up and made into a 400. It just had 2 valves no bancers, and doesn't have the same frame mounts.  Lots of UK people think it is a 4valver due to TBM's bike guide being pants.
Title: Re: DR400 mods
Post by: oldfart on September 22, 2010, 07:54:03 pm
In my eye's the the Dr  400 biggest problem are  cam jornals flogging out. Dr 500 are way too Friggin heavy.
Cloggy, front and rear wheels also interchange along with tanks.
I am running a 1978 c2 arm on my  DR 400 -  and have a alloy arm fitted to my  DR 500 ( same material used on  Pe/ Rm 1981 models ).......and yes they also fit Dr 400 to answer your question
Title: Re: DR400 mods
Post by: LWC82PE on September 22, 2010, 08:06:19 pm
The American 'enduro' spec 500's  X, Z, D etc had alloy swingarms or were at least ment to have them, there could have been a couple of steel armed ones slip theough.

The rest of the world generally had the trail version which was a lot different. These were the 'S' models so SX, SZ, SD etc

The SP500 is basically a trail DR500 'S' just re-badged as a SP in USA as they called them a SP500 as to save confusion over having 2 DR500 models and one was called a DR and one called an SP  to differentiat between enduro an trail models.

So yes the SP500 had the same steel swingarm that the worldwide 'trail S' DR500's got.
Title: Re: DR400 mods
Post by: oldfart on September 22, 2010, 08:20:15 pm
Take note  ... of RHS view @ rear of swing arm ( note it is hollow ) also type of shock used.       This should explain what Leith and I are talking about :)
http://www.youtube.com/watch?v=D28OXHDhIxA
Title: Re: DR400 mods
Post by: LWC82PE on September 22, 2010, 08:27:28 pm
That was a good video shows it well. Note the piggyback shocks and PE type forks. The trail version didnt have the PE type forks with the forks extending down past the axle or the piggyback shocks.

There would be plenty of DR pics on

http://www.bikepics.com/

and

http://www.suzukicycles.org/

and if you do a general 'google image' search
Title: Re: DR400 mods
Post by: cloggy on September 22, 2010, 08:53:08 pm
 Mystery Resolved!
 Thanks very much for that
 UK only got the DR400s; no t and no 500
 The 500 engine must be a very heavy lump, cos not much else changed
 I've got 5 or 6 heads, all ok. Never seen a knackered one but we don't get the heat, or the distance.....
Scroll down near the bottom for the third placing 1983 DR500
http://www.dakardantan.com/forum/photos-paris-alger-dakar-1983-vt1006-30.html
Title: Re: DR400 mods
Post by: LWC82PE on September 22, 2010, 09:25:20 pm
There was also 2 DR400's. There was an Enduro 'T' model and a Trail 'ST' model. Being in UK you would have only got the 'ST' i reckon. I have read somewhere that some countries continued to get DR400's in 81 but im not sure if thats 100% true.

In Australia we got a few Enduro spec 400/500 DR's but they were generally specially imported in limited numbers by individual dealers who wanted them. They were mainly ment for the north american market. They didnt have compliance plates and were not road registerable in Australia but a few non complianced 'enduro' DR's did manage to get on the roads in a few places, most likely illegally (getting a compliance plate off a trail version etc)

(http://www.vintagefactory.com/DR6.jpg)

(http://www.vintagefactory.com/DR1.jpg)
Title: Re: DR400 mods
Post by: lukeb1961 on September 22, 2010, 09:55:54 pm
nice looking bike.
Title: Re: DR400 mods
Post by: LWC82PE on September 22, 2010, 10:02:44 pm
Pretty much original except for  SW shocks, WB/Protec fork caps, Answer bars and i reckon the front fender looks like a PP with the back cut off?

more pics here

http://www.vintagefactory.com/1980_suzuki_dr400.htm

Australia should have just got this model and slapped a ADR package on it like they did with the DR250 in 82/83 Instead of having the outdated SP based bike.
Title: Re: DR400 mods
Post by: cloggy on September 22, 2010, 10:36:39 pm
 The road going DR400S was the only DR400 the UK market got and indeed they were sold as a 81 model in the UK . All mine are 81. They may have even been sold in 82. They were heavily discounted. The DR400s was pretty much identical to the T model
The T had a less restrictive exhaust, longer front forks and rear shocks, smaller front hub and different lighting and instruments. The jetting was marginally altered. The basic package was identical. So identical that this standard S  got 12th in 81 and won the Marathon [unsupported catagory]
http://www.dakardantan.com/paris-dakar-1981/d-aboville,suzuki+dr+400,19.html
Title: Re: DR400 mods
Post by: LWC82PE on September 22, 2010, 10:40:49 pm
Some of the DR's got alloy tanks too. This was also a bit random aswell, depending on what suzuki had at the time.
I have a 80 or 81 (i reckon its 80) UK suzuki sales brochure (full range) and they were selling SP400 and DR400's at the same time.
Title: Re: DR400 mods
Post by: cloggy on October 02, 2010, 05:08:07 pm
 All the UK bikes seem to have ally tanks. One sneeze and they are dented.
I had a SP400 back in the day. It was pretty awful offroad, just didn't handle. The frame is identical to the 370 apart from the cdi mounts, excellent road frame though. 370s were modded by Vic Camp Racing for road race training courses. I put GN400 forks on it and modded the engine. It would do an indicated 90 with motocross bars and a belstaff jacket, and was uber reliable.
Title: Re: DR400 mods
Post by: ozyditcher on October 28, 2010, 02:45:36 pm
Im half way done with my DRM,  Has anyone put a late model FCR CARB on? how do i up load photos ?




Title: Re: DR400 mods
Post by: Marc.com on October 28, 2010, 03:07:21 pm
I have DR400T with alloy tank and competition trip meter, there were quite a few in NZ as they were street legal with a road kit (speedo, battery for stop light, PE indicators)./

Hard to find bits for as rear guards promptly snapped off and side covers were brittle and held on by not much.