Author Topic: Older DR 600/650 thread (Pre mid 90's) (Read 35902 times)

SuperDavexlv750r · « **Reply #160 on:** December 29, 2011, 04:14:29 pm »

The carb swop helps a lot. Plus cam reprofile and we should have loads more torque under 3000rpm. And great response too.

Wildcoast · « **Reply #161 on:** December 29, 2011, 05:14:45 pm »

Will new jets , drilling the slide and airbox mods not give similar response with less outlay?
If I can cure my surging after my re-vamp I will be more than happy, maybe new pipe, filter, needle and jets with a good tune is what she needs.

Oh ja and binning my infernal cable choke for one on the carb.

I will also need to re-plate my spokes, any ideas on that one?

Veemax · « **Reply #162 on:** December 29, 2011, 05:26:51 pm »

Let me finish my learning curve on the carb ! It's all NEW but I think the jet needle is still a tad lean. ( I don't have the original washer , so am a bit lost ) , under close to no-load low-rev 3000rpm trickle, it surges. It will even digest some choke under these conditions. If I can get the part-throttle PERFECT ( it's sooooo close ) , then I'll have one of the best carbed factory Oudt DR's around. I figure lift the needle 0.5mm will do it. If it still behaves like a KM640 with a hangover at 3000 , then I'll have evidence of the Best Case carb setup , and will then maybe validate more extreme mod's to the inlet ?? Lets see. Right now the bike goes stunningly under 97% conditions and the compression with the new bore is phenomenal.

One last annoying thing I need to attend to is the oil return pipe from the head has an O-ring leak. Bitch. At least it's external, phew !

I think when I'm done with those two items, and some sag-correcting spring spacers up front, I'll be close to OEM mechanical perfection , which might be useful as a benchmark for you guys considering more serious engine/inlet mods.

My attention might, after that, go in the direction of the seat !

Wildcoast · « **Reply #163 on:** December 29, 2011, 05:48:49 pm »

I just sent my seat in today for re-vamp, will post feedback

SuperDavexlv750r · « **Reply #164 on:** December 29, 2011, 08:59:46 pm »

Quote from: WILDCOAST on December 29, 2011, 05:14:45 pm

Will new jets , drilling the slide and airbox mods not give similar response with less outlay?
If I can cure my surging after my re-vamp I will be more than happy, maybe new pipe, filter, needle and jets with a good tune is what she needs.

Oh ja and binning my infernal cable choke for one on the carb.

I will also need to re-plate my spokes, any ideas on that one?

Due tothe typeofcarb the std Mikuni BST is those mods will help marginally. The carb change makes for much more torque across the range from really lowdown and then a far quicker response on the throttle.

Can't compare the difference itappears. Carb swap is mind blowing and releases the bikes potential. Yes it is expensive todo but Ibelieve the grinfactor is all worth it.

SuperDavexlv750r · « **Reply #165 on:** December 29, 2011, 09:02:21 pm »

Quote from: WILDCOAST on December 29, 2011, 05:48:49 pm

I just sent my seat in today for re-vamp, will post feedback

Unless they adding gel it may not be such a great result.
just did my XLV750R seat and it is better but not remarkable.

Veemax · « **Reply #166 on:** December 30, 2011, 06:22:02 am »

Oh yes, the carb slide IS drilled ! What I mean is this model DR has two slide holes as stock. The > 96 DR has a single hole. The thinking goes that slide flutter is reduced with the single hole, and therefore the slide wear , as I've shown earlier here !

I am tempted to add a top hole to the airbox , it sure helped my 08 DR ... maybe in the fullness of time .....

I have had only success and never a fail opening an airbox and jetting up. You need to not mind about intake noise though , but normally with an aftermarket zorst the extra decibels overcomes the intake honk : )

I also urge you not to make your bike TOO responsive off-idle ! My wife's XLX350R has a pumper carb, it's a BITCH in technical sections because its TOO damn responsive. Out there in Hereroland between the klippe and the sand and thorns, the last thing you want is insufficient off-idle control , and a bike which tears off into the bushes with a bump to the twist grip !

Super-response is for Motards and urban wheelies. Ja the taxis used to clear the way for my SM610 and then request a wheelie ...you don't want a snorting beast like that north of Windhoek ....

SuperDavexlv750r · « **Reply #167 on:** December 30, 2011, 09:42:37 am »

I hear you. All I am looking for is more torque usable at lower rpm as I believe the bike will handle tech sections better and you won't have to burn the clutch out trying.

Wildcoast · « **Reply #168 on:** December 30, 2011, 11:01:04 am »

Seems the balance between mild and wild is what Im after, I have heard the new needle from the dyno jet kit helps a bit, any comments on that?

SuperDavexlv750r · « **Reply #169 on:** December 30, 2011, 11:09:32 am »

I believe it does help but still not good under 3000rpm. Better response but doesn't appear to sort low down torque issues.

Wildcoast · « **Reply #170 on:** December 30, 2011, 11:13:52 am »

To purge the surge is my mission, Im about to do an order from pro-cycle, was wondering if the dyno jet kit was the way forward?

Veemax · « **Reply #171 on:** December 30, 2011, 11:45:40 am »

Purge The Surge : )

I reckon the guilty party is a hefty dose of valve overlap from the cam , combine that ( relatively high flow rate through engine at relatively low rpm ....for a thumper that is .....because of the cam ) with any less than ideal fuel/air , and you have this tendency to alternate overun/bog/overun/bog ....

So you have to get really perfect fueling to fight what the cam is doing , and even then there is no guarantee within the limits of the carb, you'll get it right.

I got massive improvement when I reset the float height, then again, another step in the right direction with a restored nozzle, then again, another step with new nozzle and new needle and new slide , now I hope for the last tweak with the needle adjustment I have planned.

If it still has elements of surging, well, thats the cam , and there's little one can do in the end except toss the whole BST carb and/or change the cam , but it's really near perfect now so I'd not contemplate that.

Like I suggested, maybe stick around to see if my last needle tweak doesn't get me surge-purge !

But you catch me a little off guard, as at 5am this morning I moved my DR into my work area to sort the oil leak on the return pipe O-ring first.

I'll sort that out and then lift the needle one shim and test ...

It's so damn close to RIGHT that I'm pretty sure I can get there, hell, my carb and engine are now brand new , it should go like it did in 1994.

SuperDavexlv750r · « **Reply #172 on:** December 30, 2011, 11:48:42 am »

Read the write up on Thumpertalk. There is a long thread. That should give you answer you require. Also look under Pro cycles FAQ. I think they suggest the Pro cycle kit and have some other answers there too.

The kit increases power and torque but the torque curve is still steep upto 3000rpm and then seems to really perform.

I too want no surge low down and that seems to be a function of how the BST carb operates unfortunately.

You can also mail Pro Cycles and they can explain it better. They have quick respnse and very helpful.

Wildcoast · « **Reply #173 on:** December 30, 2011, 11:59:44 am »

Just placed my order, dyno jet kit, mixture screw , on carb choke , Acerbis and vapour.....
Will be putting a new pipe on and watching Veemax's carb settings closely.

Veemax · « **Reply #174 on:** December 30, 2011, 12:28:56 pm »

Definitely not gonna land at your local PO !!! HAHAHAHAHAAAAA.

Mmmm, bit jealous of that tank * insert green face*

SuperDavexlv750r · « **Reply #175 on:** December 30, 2011, 02:36:42 pm »

Damn I am just as jealous.

Veemax · « **Reply #176 on:** December 30, 2011, 04:07:46 pm »

That's it I guess. My 1994 DR650 SER rebuild project is complete. I've fixed the return pipe O-ring leak. The O-ring was twisted like the waste band of a schoolgirls knickers. They say put it in with GREASE. They know stuff. Got to ease that thing in then work it so it settles without winding it into a pretzel.

The carb is DONE. It's hard to find any fault. It idles, it creeps, it pulls, it comes off full throttle back to idle WITHOUT STALLING , geeze guys, this has been a bloody test of my patience !

I can say this. The BST40 works when it's new. It ages fast. It dies even quicker than your piston/bore clearance when some fukwit lets the air cleaner rot and fall apart. If you make it NEW again, it works and works well. Maybe not as good as an alternative. It has a bad rap the BST , but it's the same carb on many other bikes.

It would probably benefit from a 1.2 pilot air jet to replace the 1.3 , IMHO , I read that someplace, it makes sense to me now.

Given what folks say about other carbs, if I were to do this dance again, I'd go aftermarket. However, it did only cost about R1700 all-in to replace all the wear parts, and thanks to Motolab for that, or it would be IMPOSSIBLE with Suzuki, who don't have those plastic parts to sell !

Anyway, my carb is set now to wear IN , as opposed to wear OUT. As the needle/nozzle gets worn, it will get better instead of worse, well, at least initially !

The only item left on my To-Do list for this bike is to replace the front disk which is at minimum thickness of 4.0mm , I'll take my time with that.

Maybe some fork vroeteling but no rush either.

So I have a near-stock 1994DR painted with Velvaglo Dirty Khaki , but it runs sweeeeetly , FEELS like a relatively new ride, goes like snot compared to most 650 thumpers, including my own Stage 1 '08 DR , and my all-in wallet I think is R37 000 for a bike with... mmmmm , about another 75 000km live left in it as it stands.

When I think I sold my KTM640 for R58k , I am very, very happy with my Old School Downgrade !!!!

Keep the faith gents, this bike is worth the work and the fuss.

And as I sit here the renewal notice arrives ! Yes, one full year it took.

Do It !!!

Wildcoast · « **Reply #177 on:** January 03, 2012, 02:20:35 pm »

Is the exhaust header on the older DR stainless steel?
Does anyone have any contacts as to who does spoke lacing and plating in Northen JHB?

I have been getting mixed feedback as to what to do with my bikes frame, powdercoat or paint, any opinions on that one?

SuperDavexlv750r · « **Reply #178 on:** January 03, 2012, 03:03:31 pm »

Is header Stainless steel - I don't think so.

Saw some ads for people doing spoke lacing in local magazine - not sureif Bike SA, or Offroad and Adventure or Dirt &Trail Bike Magazine. There is someone advertising on Gumtree that does restorations on older bikes and could probably point you in right direction.

Powdercoat I think is a tougher and harder finish. But like Veemax who used Velvaglo this is also a very hard wearing finish and should work as well - if not better as if you do chip or scratch finish you can touch it up far easier. IMO

Veemax · « **Reply #179 on:** January 03, 2012, 03:51:49 pm »

Whatever coating is on my oldie header is intact. But I can share this, with my wifes XLX350R rebuild I took the ( carbon steel ) headers to my mates business with a sandblaster, then, with it down to base metal , I went next door to another company that does all manner of plating and they acid dipped it for me, I then blasted home as the rust starts in minutes ! I then used VHT rattlecan and followed the instructions to the letter, using my wifes oven for the three-stage cure process. So far so good, from deep rust to a solid intact surface.

I think if pressed harder for a better solution I'd go sandblast/acid etch/copper plate/ nickel plate

I've relaced many wheels, it's a pain in the butt, but it can be done, with beer on one side to maintain Zen-like equilibrium.

I've got a rear rubber change imminent, will use the opportunity to continue the Velvaglo disease, by spraying rims and spokes and hubs.

My final aim is to have a bike that cannot rust even if I parked it on Durban beach for a week.

I've been tearing around the Peninsula on my bike right this minute trying to make it leak oil, spit, fart, wobble, or misbehave. Had the engine blistering hot ... nothing doing.

Can't break this bike or find a fault or a leak or a problem.

With this kind of treatment a Husky SM610 would sweat coolant from the head gasket.

Keep on guys, keep on !

Oh yes, been meaning to ask, those Vapour dashboards ? Worth it ? I wouldn't mind not having to multiply and dived by 1.6 all the time