No throttle free play RD400C

[Membername]

I installed the carbs and the throttle cable and synced the carbs, but there is no throttle free play.  I have the stock cable and throttle tube.  The cable routing is below.  I did have the three way splitter open to lube it.  Any ideas? 

[quocle603]

Free play meaning?

I usually associate that with any "slack" on my throttle or slide cable.

[Membername]

By throttle free play I mean the slack that gets taken up before the throttle tube action starts to lift the slides.  I think the spec is 2-7mm. 

K

[quocle603]

You would need to adjust the long adjustment nut at the top of the throttle for that. Screw it in for more play and out for less.

Why do you want play? You want to twist and go, release and stop, repeat.

[Organicjedi]

There should be a little play.

Adjust the nut like Q said. Turn the bars lock to lock when checking tension on the throttle to make sure the cable isn't getting hung up anywhere. Also check in the switch to make sure the cable is seated properly on the tube.

The important thing is that the slides slam closed when the the throttle is released and open all the way when pulled.

[SUPERTUNE]

I have had this problem with brand new OEM 400 throttle cables from Yamaha. The fix was to grind a little off the throttle tube at the stop. This was with the slack adjuster adjusted in as far as it will go in.
The screw hole for the throttle tie bolt is also not in the right place and requires filing the hole a little offset with a small die grinder or jeweler's file.
Chuck

[Membername]

There should be a little play.

Adjust the nut like Q said. Turn the bars lock to lock when checking tension on the throttle to make sure the cable isn't getting hung up anywhere. Also check in the switch to make sure the cable is seated properly on the tube.

The important thing is that the slides slam closed when the the throttle is released and open all the way when pulled.

The throttle lock nut at the handlebars is fully in.  No play at any point, lock to lock.  I opened the switch twice, but maybe there is something I am not understanding about how the cable goes in.  There is barely slack for it to fit on the track it runs on. 

[Membername]

I have had this problem with brand new OEM 400 throttle cables from Yamaha. The fix was to grind a little off the throttle tube at the stop. This was with the slack adjuster adjusted in as far as it will go in.
The screw hole for the throttle tie bolt is also not in the right place and requires filing the hole a little offset with a small die grinder or jeweler's file.
Chuck

Do you mean the screw right next to where the throttle cable enters the switch?  The position seems ok on mine, but I will double check it. It seems like there should be a washer there to even out the plate going to the throttle cable (pic, red arrow).

I'll look at the throttle tube, maybe there never was any free play?  I can ask my uncle if he remembers, he was the original owner and maintained the bike very well.  Right up until he put it under his deck for 30 years. :)

K

[SUPERTUNE]

I can see now that you do have the original cable, the elbow and tie clamp are silver, the new throttle cable elbow from Yamaha is now black and the adjuster is plastic!
No washer needed, looks like it should in the pic.
Double check the 3 way joint and make sure its snapped all the way together?
Chuck

[Membername]

Well I tried to push the splitter together more but it did't really alter it.  I've disconnected the carbs about 10 times trying to solve this, and opened the splitter 10 times.  I do have one broken strand in the cable near the oil pump, and the stop on the end of the cable that goes onto the pump is looking a bit rough so I am going to buy a new OEM cable.  It may not solve the problem (especially knowing what Chuck said above) but I probably need it anyway. 

K

[SUPERTUNE]

My local dealer was $98 for one.  :(

C

[Evans Ward]

If you can locate someone locally to you who is able to get Yamaha parts for dealer cost, the cable is just under $80.

[m in sc]

how far out are the adjusters at the carbs? also, verify the main cable is seated correctly in the splitter union.

[Membername]

Got the new Yamaha cable and it's a little bit better.  Here is a pic of the carb adjustment.

[SUPERTUNE]

Got the new Yamaha cable and it's a little bit better.  Here is a pic of the carb adjustment.

Trim off a little of the plastic on the throttle tube stop, the the front single cable is the problem child with a new OEM cable from Yamaha.
Chuck