Hose Orientation for the Auto-Choke circuit

Apologies if this has been covered, but my searches of the forum didn't find any useful info.

I was reinstalling the throttle body assembly and reconnected the two coolant hoses for the auto-choke (forgot their original orientation).

I oriented the hoses in a way that seemed to make the most sense based on the shape of the bends and their lengths, but I am not sure if the auto-choke is working. The temps are here are not very cold yet so maybe that's why the auto-choke does not appear to kick in when I first start up the bike...

Can anyone on the forum confirm whether or not there is a specific order of connecting these two hoses, i.e .which hose connects to which of the two pipes?

Can't specifically comment on routing because I don't have a GenII to look at any more.... one would think as long as there is flow, it should heat up the module. Also not sure the temperature the fast idle should kick in, but most likely around 90-100F coolant temperature. So mostly, in cold starts, it would kick in for a bit at normal ambients.

The FSM doesn't seem to detail much about the fast idle mechanism..... in Throttle Bodies section 7-6, hose description is 4 hoses are outlets (two ends and two on the bottom) and only one is the inlet (attached to 90 degree fitting on the back side)..... hopefully that will give you some clues. Unfortunately that view does not quite resemble the parts diagram.

Thanks for the input RaYzerman19, but I'm still a bit confused (as usual).

If I had to guess I would say that the hose from the coolant pipe (#27 in the above pic) should connect to the input of the auto-choke since the other hose (#28) goes to the radiator, which would mean that the coolant in that hose would only heat up once the thermostat opens, meaning that the fast idle is no longer required... Assuming that logic is correct, the only remaining question is whether this auto-choke circuit is directional, and if it is, which of the two pipes is the input and output.

Having said that however, as far as I understand how this circuit works is that it has some kind of wax type material in the valve which liquefies as the coolant running through this assembly heats up. So theoretically it should not make any difference as to which hose connects to which pipe?

Scouring through the FSM.... check 2-41 which outlines the coolant hose layout..... I would think flow is flow..... but... check it out.

There is a bypass circuit which does not flow through the thermostat, which I'd think would start to open at a higher than necessary temperature to open up the fast idle circuit.

Got some pics of my '06, don't know if any might help.

Try around here. Might show you something.

The hose from the radiator goes to the lower connection on the wax motor.

Shouldn't matter, route the hoses conveniently.

the auto-choke does not appear to kick in when I first start up the bike

Click to expand...

What is the RPM when you first start up the bike ?

The bike always starts on fast / cold idle, ie the Fast Speed Idle Circuit. If not someone has played around with the adjuster or has disabled it.

As the wax motor heats up, via the 2 small coolant pipes, it blocks off the 4 fast speed idle valves ( pushes them in) and the RPM drops back to the normal running hot RPM. It is the 4 air valves that govern and drop the RPM back to a normal hot idle RPM.



The transition between fast/cold idle to warm/normal idle.

I'm activating the plate on #1 TB.

If the bike doesn't readily drop the RPM as it heats up, most likely the small hoses are blocked up with crud.



Fast idle RPM is adjusted by the adjuster at the bottom of the throttle bodies while the hot / normal RPM is adjusted down by the side of the frame of the bike, under the plastics.

Cold / fast idle can only be adjusted while the motor is COLD.

As far as I noticed, the coolant pipes only go on one way.

Bottom hose of the wax motor to the radiator, wax motor top inlet pipe adjacent to / near the thermostat.

This looks like an old thread and may have died but 2 weeks ago I replaced the same 2 hoses going to the wax valve and now I have no choke.  It will not start without giving it lots of throttle and reving but once warmed up it runs fine.  Seems to me that lack of circulation to the wax valve is only high idle problem, not a choke problem.  I'll have to go back in under the tank and see if I left somethin unplugged.    

Check it, but... 

Are you getting an error code of any sort - specifically #14?

Just another possibility for poor running, especially when cold.  Fairly common.  (Although when there is a problem, you should first suspect the last thing you messed with.)

RossKean said:

Check it, but... 

Are you getting an error code of any sort - specifically #14?

Just another possibility for poor running, especially when cold.  Fairly common.  (Although when there is a problem, you should first suspect the last thing you messed with.)

Click to expand...

Thanks for the comment.  Nice to know someone is paying attention and cares enough to try and help.  The last thing I messed with to replace the small diameter coolant hoses going to the wax valve included the gas tank, the throttle bodies and the air box.   

I have no error codes indicated which is amazing because the engine barely runs without pumping tee throttle.  Is the self diagnostic code no. 06 for coolant temp in degrees celsius? because that's what I found on another site regarding other model Yamahas.  If so then that might be the problem because it says 81 but if it is degrees F then that's about right.  Outside Air Temp (no. 05) says 84 and that's about what it is outside right now.  In diagnostic code 61 I have 13, 14, 15, 22 and 30.  I need to figure out what that means.  

And code 62 says 6.  I assume that refers the number of codes thrown as listed in code 61.  Maybe I'll try to clear these and see what happens.  

From the FSM.  Try clearing them and see which ones come back.  I suspect that the Code 14 that I mentioned in the earlier post could be the root cause.

Thank you very much.  Do you have a list of the diagnostic codes?  

I'm not sure what 03 is.  And I'm not sure if the Temp sensor readings are in F or C.

01  Throttle Pos  and mine is 16 at closed, 101 at wot

03  maybe differential pressure between outside air and air intake ???   mine says 100  is this mm of Hg?

05  Air Intake temp  84

06  Coolant temp  81

07  speed sensor  0  and then counts up when rotating the rear wheel

08  lean angle  0.6  I did not attempt to test the tip over position

09  bat volts  11.4 and drops to 11.1 when I hit the brake

20   side stand on but stayed on when I put it up ??

21  neutral switch on but switched off when I put it in gear

30  EEPROM code 00

31, 36, 37, 38, 39, 48, 50, 51, 52, 57, 60 various coil and injector and air duct solenoids activated 5 times per second whatever that means BUT all my codes are 00  

61 error code memory and mine was 13, 14, 15, 21, 22 and 30 before I reset it

62  number of error codes and mine was 6 before I reset it

70  00

A service manual is really helpful to have...

Have a look at this post by "ionbeam" and see if it helps.  Both Gen I and Gen II codes.  I believe the temperatures are in °F.

As I mentioned, I think I would note all of the codes/faults, clear them and see which ones come back.  

Thank you a ton.  I snuck out of the office this morning to do the reset but did not take the time to try and start it.  It takes so many starts and so much cranking to get it running enough to warm up that I doubt the battery can do it a second time without running long enough to recharge.  And it's easier to start in the heat of the afternoon so I'll provide an update after I get home this evening.      

It has not thrown a new code after riding home last night and back to work this morning (It's only a mile).  It's still hard to start and runs crappy until it warms up, like no choke (or no enrich circuit) but it's getting a little better.  Maybe old gas?   I have added a gallon of clear "no ethanol" and a half a can of sea foam to the half tank of 6 month old gas so maybe that's the issue.  The code 06, coolant temp, gets up to 150 with riding a mile so I assume that is degrees F.  I'm still not sure if a reading of 99 or 100 for code 03 is normal but it is not throwing a code.  And I checked 50 fuel pump, 51 Rad fan, and 52 headlights and they all cycled normally.  

So next is I'm going to pull the tank and dump all the gas out and put fresh in.  I'll report back when I figure this out.

And by the way.  I've soldered the S1, S3 and S6 ground spiders including a separate 12 ga. ground wire from S3 to S6 to the battery ground terminal (to avoid any issues with the coupler).  My symtec heat demon grip heaters are grounded through the added 12 gas. ground.  And I've lubed S6, S7 and S4.  And the factor recall fix on S4 has been completed.   I know, belts and suspenders.   

If you decide to replace the wax motor I have several used ones at hand... free to you except for shipping. Hopefully it's gas. If not, offer is open.

Old-old gas will cause the starting problems you've described. Get a fresh tank and take the bike out for a good long run.

Good luck!

~G