Hello everyone,
i would like to by an aftermarked cable on HVC Cycles
hvccycle.net/yamaha-dt250-dt360-dt400-th...-cable-437-26311-02/
Its announced for fitting 250 B and 400 B.
But in the spare list, the parts numbers , the lower cables 400 and 250 are different.
- Does the cable really fit on both bikes?
- What is the difference in OEM lower cables ?
Regards from Germany

28mm vs 32mm carb so slide travels about 4mm farther on the 400. 

It should be possible to design one cable that works on both.  I'm pretty sure KDI has done the same thing on their cable sets for the 68-73 DT/RT? 

I don't have personal experience with this HVC cable set...  I know many members here do have experience so hopefully they'll comment...  I can only say that I don't recall anyone posting that it didn't work.

Mark, you are right, the slideway of the carb must be 4mm more, as the carb diameter is 32, not 28mm. But the twist of the throttle grip remains the same for both, carb and oil pump.
If the oil pump would limit the way, the cable goes, bigger carb would not open completely. So i guess the oil pump pulley of the DT 400 has a bit more diameter, as the 250, to equalize the way, twist grip supplies.
But then question remains, what is different in lower cables 400 vs 250. Parts list mentions the same lenght for both.
Lots of question marks

Which parts lists are you looking at, Wessi?

CMSNL shows the same lower cable (for carb and oil pump) as fitting all DT250, DT360 and DT400 from 1974 to 1976 inclusive. Also, my European parts list for 1974 DT250 and DT360 shows both using the same cables.

I have a parts list 1976, DT 250  ( Type 512) and DT400 (Type 513) for Europe
237-26311-02 Wire, throttle 1  upper (590mm) for 250 and 400

498-26312-00 Wire, throttle 2  lower (440mm) for DT 250
500-26312-02 Wire, throttle 2  lower (440mm) for DT 400

Maybe the bending angle of the carb-side tube is different.
 

If the parts that you show the numbers for include the rubber boot that sits over the carb cap, then this could account for the difference - CMSNL indicates that the 250 and 400 use different boots (different diameters?).

Yes, the boot if included with the lower cable could be it. 

The 400mm dimension could be the outer sheath of the cable?  The inner cable is what I'd expect to have a slightly longer dimension for the larger 32mm carb or yes, the cable fittings could be different.

I'm pretty sure that originally the lower throttle cable for the DT/RT were slightly different?  Somewhere I might have some dimensions, I will check. 

Thank you both.
This is most likly the answer, the rubber boot.
As the boots have their own part numbers (250 and 400) i thought they were seperate. But the broken line around the lower wires could mean, the boot are include in the wires