Hello,
I have had some hot start issues with my sr viper xtx + mcx190.
These have been done and tested:
-new battery
-valves checked
-stub shaft checked
-throttle body synchroniced
-added some fuel to idle rpm (with mcx gen 5 box). Warm Idle afr is now at 13..14.
-latest ECU map (2019 version)
-new iac valve
-intake temperature sensor moved to intake pipe
It starts good on first attemp cold (let pump cycle). Also starts on first attempt if coolant is below 80c (start without letting pump cycle). If i let pump cycle when warm it normally takes two attempts.
When coolant gets to 85…90c it is hard to start. Usually this is after short shut down (stop for gas etc.) takes 2-3 long cranks.
has anyone tested throttle body heater line shut off or bypass for these? There might be some heat soak?
Thank you.
I have had some hot start issues with my sr viper xtx + mcx190.
These have been done and tested:
-new battery
-valves checked
-stub shaft checked
-throttle body synchroniced
-added some fuel to idle rpm (with mcx gen 5 box). Warm Idle afr is now at 13..14.
-latest ECU map (2019 version)
-new iac valve
-intake temperature sensor moved to intake pipe
It starts good on first attemp cold (let pump cycle). Also starts on first attempt if coolant is below 80c (start without letting pump cycle). If i let pump cycle when warm it normally takes two attempts.
When coolant gets to 85…90c it is hard to start. Usually this is after short shut down (stop for gas etc.) takes 2-3 long cranks.
has anyone tested throttle body heater line shut off or bypass for these? There might be some heat soak?
Thank you.
- Joined
- Apr 13, 2003
- Messages
- 21,312
- Age
- 54
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- Schofield, WI
- Website
- www.totallyamaha.com
- Country
- USA
- Snowmobile
- 2020 Sidewinder SRX
You can drill more by pass holes in thermostat.
i will test the throttle body heater shut off valve first. Will inform how it works out. With the turbo there should be enough heat to intake when trail riding without the extra coolant line .
Installed the shut off valve to clutch side. The hot start issue seems to be fixed now. Tested to temperatures when cooling fan comes on and was good now. I used small B&S fuel valve.
With the turbo i dont think there will be many times i have to open the valve.
With the turbo i dont think there will be many times i have to open the valve.
Attachments
- Joined
- Apr 13, 2003
- Messages
- 21,312
- Age
- 54
- Location
- Schofield, WI
- Website
- www.totallyamaha.com
- Country
- USA
- Snowmobile
- 2020 Sidewinder SRX
Awesome!! Keep us posted.
Update to this one. This coolant shut off didn’t do much after all. The hard start remains. It is like cranking safety switch off when temp is above 90c. Crank rpm is 400-500. When coolant is below 80c there is no issues. In between 80-90c it is random 2-3 starts usually. Ride with Apex 2011 last time and it had instant start up in same conditions. The ecu has latest map 0730-344.
I have tested to feed ecu from different battery. No success.
Tried to change idle area mixture without any help. Also tried other set of plugs.
Next step is to check compressions cold vs hot. Maybe i will valves are getting tight. With Yamaha dirt bikes it was usually tight valves when it wouldn’t start.
I have tested to feed ecu from different battery. No success.
Tried to change idle area mixture without any help. Also tried other set of plugs.
Next step is to check compressions cold vs hot. Maybe i will valves are getting tight. With Yamaha dirt bikes it was usually tight valves when it wouldn’t start.
