Author Topic: Older DR 600/650 thread (Pre mid 90's) (Read 34462 times)

DeepBass9 · « **Reply #580 on:** February 20, 2012, 11:23:30 am »

The Wilbers springs made a huge difference to my bike (and also replacing the fork oil at the same time). Much better handling on the dirt, and no more sag and dive on braking.

Veemax · « **Reply #581 on:** February 20, 2012, 02:27:27 pm »

I can confirm that my bike ran fine with buggerall compression , also used 145ml oil / 1000km ....then it SUDDENLY went into a massive decline.

Once open the full horror of wear and scoring presented itself. Quite amazing how well it behaved up until the point of caving in !

It was all traceable to a farked air filter of course , some homemade piece of crap ( one of the ) previous owner thought was a fitting filter !

But before a full rebore ... not a sticky valve maybe ?

SuperDavexlv750r · « **Reply #582 on:** February 20, 2012, 06:24:44 pm »

@DeepBass- thanks for info.

@LeCap thanks for info - I am thinking of re doing whole motor top and bottom end. would it be possible to re-sleeve head and fit post 1996 DR piston? i.e increase the bore to 100mm?

With the stroke of pre 1996 DR - this should give me a capacity boost to about 710cc.

Is this do-able do you think?

volroom · « **Reply #583 on:** February 20, 2012, 07:44:28 pm »

"If the springs are really bad they will not fully extend the forks any more. Loosen upper triple clamp clamping bolt(s) & remove fork tube plug (front wheel in the air). If the spring does not push against the plug = if the spring is not preloaded the springs are scrap"

So - just making sure, the fork tube plug - what's that exactly?Is it the top part of the fork legs that you can remove with ratchet and socket to get hold of the springs?

If that's the case, I loosen the triple clamp bolts - why?

Is this test as simple as removing fork plugs and seeing whether the fork springs still push back when you fasten them again?
Sorry, just want to make sure. Was thinking of replacing the fork oil anyways

What does the wilber springs go for BTW?

lecap · « **Reply #584 on:** February 21, 2012, 10:37:26 am »

Quote from: SuperDavexlv750r on February 20, 2012, 06:24:44 pm

@DeepBass- thanks for info.

@LeCap thanks for info - I am thinking of re doing whole motor top and bottom end. would it be possible to re-sleeve head and fit post 1996 DR piston? i.e increase the bore to 100mm?

With the stroke of pre 1996 DR - this should give me a capacity boost to about 710cc.

Is this do-able do you think?

Don't think this is doable since the DR650SE uses a sleeveless plated aluminium cylinder. The old DR650 has a cast iron cylinder liner.

Better to check if you can get some serious big bore stuff from Wössner or Wiseco. The DR750 piston and rings would be suitable to run in a sleeved cylinder too but I doubt you can make the 650's cylinder and crankcase cutout big enough to make space for the DRBig piston.
Gudgeon pin diameter is another consideration.

Quote from: volroom on February 20, 2012, 07:44:28 pm

So - just making sure, the fork tube plug - what's that exactly?Is it the top part of the fork legs that you can remove with ratchet and socket to get hold of the springs?

If that's the case, I loosen the triple clamp bolts - why?
...
What does the wilber springs go for BTW?

Yes. You have to loosen the upper triple clamp because the clamp deforms the tube enough to pinch the plugs.

The springs are R1500 at the moment. I am waiting to see what the ZAR / € exchange rate does. Price might come down a bit in the second half of the year.

volroom · « **Reply #585 on:** February 21, 2012, 10:40:35 am »

Thx LeCap, will check it out. Manual says 566ml front fork oil - that for both fork legs, or only one?

Veemax · « **Reply #586 on:** February 21, 2012, 11:30:25 am »

That's about right fork oil capacity but it's much better to use the airspace measurement with the spring out. I just did mine the other day the oil qty in the manual was about 20ml too much.

The head space is an important factor in the fork action due to it's compression

volroom · « **Reply #587 on:** February 21, 2012, 04:58:13 pm »

Quote from: Veemax on February 21, 2012, 11:30:25 am

That's about right fork oil capacity but it's much better to use the airspace measurement with the spring out. I just did mine the other day the oil qty in the manual was about 20ml too much.

The head space is an important factor in the fork action due to it's compression

thx Veemax, don't see procedure to follow in manual. do you know if it's there?

SuperDavexlv750r · « **Reply #588 on:** February 21, 2012, 05:11:58 pm »

Don't think this is doable since the DR650SE uses a sleeveless plated aluminium cylinder. The old DR650 has a cast iron cylinder liner.

Better to check if you can get some serious big bore stuff from Wössner or Wiseco. The DR750 piston and rings would be suitable to run in a sleeved cylinder too but I doubt you can make the 650's cylinder and crankcase cutout big enough to make space for the DRBig piston.
Gudgeon pin diameter is another consideration.

@Le Cap- If I understand you correctly it may not be possible to machine the cast iron head to accept a 100mm sleeve?

I did have a look at the supplier of sleeves to Pro - cycles and they seem to have a thin walled very rigid cast iron liner range that might do the job.

I know they do a 97mm Wiseco Piston mod on the old DR 650. Do you think it would seriously weaken head to take another 3mm out the diameter?

It seems the DR650SE piston and old DR have same gudgeon pin diameter, waist height, etc and looks possible to fit on the 92 DR conrod.

Checking with Pro Cycle- but they can"t answer accurately as they have never done a 100mm bore mod.

Veemax · « **Reply #589 on:** February 21, 2012, 05:12:09 pm »

Yup !

Veemax · « **Reply #590 on:** February 21, 2012, 05:16:42 pm »

"@Le Cap- If I understand you correctly it may not be possible to machine the cast iron head to accept a 100mm sleeve?"

HEAD ? No , dude , NOW you're confusing me ! You mean CYLINDER surely ?

SuperDavexlv750r · « **Reply #591 on:** February 21, 2012, 05:18:49 pm »

Quote from: Veemax on February 21, 2012, 05:12:09 pm

Yup !

SuperDavexlv750r · « **Reply #592 on:** February 21, 2012, 05:21:54 pm »

Quote from: Veemax on February 21, 2012, 05:16:42 pm

"@Le Cap- If I understand you correctly it may not be possible to machine the cast iron head to accept a 100mm sleeve?"

HEAD ? No , dude , NOW you're confusing me ! You mean CYLINDER surely ?

You must check how confused I am?

Been a long day and at this point a head is a barrell is a cylinder is a block is whatever.

Veemax · « **Reply #593 on:** February 21, 2012, 05:23:03 pm »

I should clean up my act, the YUP is to Volroom on the manual includes the headspace measurement ....

But interested in the BIG BIG bore idea of yours , however , without the casings and stuff on the bench, we're all gonna be speculating...

But hey, cat iron liners rock , nicasil sucks .... it would be fun to push the limits eh ?

SuperDavexlv750r · « **Reply #594 on:** February 21, 2012, 11:08:39 pm »

Quote from: Veemax on February 21, 2012, 05:23:03 pm

I should clean up my act, the YUP is to Volroom on the manual includes the headspace measurement ....

But interested in the BIG BIG bore idea of yours , however , without the casings and stuff on the bench, we're all gonna be speculating...

But hey, cat iron liners rock , nicasil sucks .... it would be fun to push the limits eh ?

When cylinder is off- i am going to seriously check out possibilities of 100mm bore.am sure pistonwillfirif head can besafely re machined.

And then some other tricks to improve cooling and reliability and make some power...

Veemax · « **Reply #595 on:** February 22, 2012, 08:32:20 am »

to quote someone with a good turn of phrase , " The DR bottom end is as reliable as an ANVIL "

I reckon with a larger oil cooler ( like the newer DR ) , high compression ( 10.2 - 10.5 : 1 ) , a big bore , expanding link pipe exhaust , open airbox , pumper , and a bit of head flowing and exhaust header cleverness , you could wake that beast within BIG time.

The great thing about these oldtimers is if yer gonna look for a sacrificial Lamb , you are working off a budget platform , but a model with plentiful spares and spares bikes with which to stock your garage ...

My DR with 30 000 miles on the crank , abuse and neglect , had ZERO and I mean ZERO big-end play when the top end was off.

When you look at the strength of those components you wonder how far you could push it !

I recall the old misty days of the GS750 , you could put a blower on that bottom end and go to 150 bhp with a bone stock mill , if you did that to a Kawa it would fold like tin foil.

Old Suzooks are TOUGH. 100mm bore ... YEAH !!!

SuperDavexlv750r · « **Reply #596 on:** February 22, 2012, 11:57:22 am »

Quote from: Veemax on February 22, 2012, 08:32:20 am

to quote someone with a good turn of phrase , " The DR bottom end is as reliable as an ANVIL "

I reckon with a larger oil cooler ( like the newer DR ) , high compression ( 10.2 - 10.5 : 1 ) , a big bore , expanding link pipe exhaust , open airbox , pumper , and a bit of head flowing and exhaust header cleverness , you could wake that beast within BIG time.

The great thing about these oldtimers is if yer gonna look for a sacrificial Lamb , you are working off a budget platform , but a model with plentiful spares and spares bikes with which to stock your garage ...

My DR with 30 000 miles on the crank , abuse and neglect , had ZERO and I mean ZERO big-end play when the top end was off.

When you look at the strength of those components you wonder how far you could push it !

Oh yes baby!

Some thermal coatings too and guess what...

Robust, reliable and a schocker for the newer bikes.

I recall the old misty days of the GS750 , you could put a blower on that bottom end and go to 150 bhp with a bone stock mill , if you did that to a Kawa it would fold like tin foil.

Old Suzooks are TOUGH. 100mm bore ... YEAH !!!

volroom · « **Reply #597 on:** February 22, 2012, 03:48:08 pm »

hmmm. Manual does show what to do with the forks. I take it it's 566ml PER FORK leg. Usually sold in 1L bottles...

volroom · « **Reply #598 on:** February 22, 2012, 05:19:07 pm »

This small hole in the airfilter spotted...looks almost as if it's supposed to be there...against my common sense. Can't remember if it was there when I bought new. Does it look familiar? If not, how can I close up that little hole - tell you what, I'm not going to fork out another R250 for stock airfilter anytime soon, bought that a couple of weeks ago!

SuperDavexlv750r · « **Reply #599 on:** February 22, 2012, 05:57:12 pm »

Quote from: volroom on February 22, 2012, 05:19:07 pm

This small hole in the airfilter spotted...looks almost as if it's supposed to be there...against my common sense. Can't remember if it was there when I bought new. Does it look familiar? If not, how can I close up that little hole - tell you what, I'm not going to fork out another R250 for stock airfilter anytime soon, bought that a couple of weeks ago!

That must be the improved multi air and dirt ingress filter.

Very disappointing - dont look like it should be there at all.