[allanpresley8]

I've got a 1999 VZ800, it keeps over heating.
New battery, new switches, new ignition coils, carbs rebuilt, the bike has no thermostat.
Checked impeller etc. Any assistance will be appreciated thanks.

 

[Porky]

Welcome to a great forum!

Thermostats are designed to keep coolant IN THE RADIATOR to maintain the correct temperature. I would drain all of the old coolant and put a new thermostat in and see if it helps.

Sam

 

[farmer bill]

Agree with the thermostat and be sure the cooling fan is coming on.

 

[Critter]

Welcome, ditto on the thermostat

 

[allanpresley8]

Welcome to a great forum!

Thermostats are designed to keep coolant IN THE RADIATOR to maintain the correct temperature. I would drain all of the old coolant and put a new thermostat in and see if it helps.

Sam

View attachment 78017

Thank you all for your guidance, however I've looked everywhere possible, but there isn't anywhere that a thermostat is missing, the bike didn't come with one.
Does anyone have a diagram of where it might be located?? Thanks in advance.

 

[Porky]

Everywhere possible??? A GOOGLE check found many topics about your thermostat:

https://duckduckgo.com/y.js?ad_domain=partzilla.com&ad_provider=bingv7aa&ad_type=txad&eddgt=Ay2ynD6ba6ecFtaN9EhR7Q%3D%3D&rut=49c83130b2aa12880564d90c82de2faf6fcb6da2862b8818740d09c4f2438222&u3=https%3A%2F%2Fwww.bing.com%2Faclick%3Fld%3De8oGeNNCVOJZ5aHYgy4MHzfzVUCUx8kaxY%2D0oKtyKF_FkHLadREoyjKk_bHu05vLkPOux_Qyijdw78ihO0IV%2DumKIDq9mJqdyAFfO_vHTe0qtEdreoCT6e0gl9ieNzLHVSVgT1uZLqjIMJy4Be%2DftSlmQPh0w25CzgONeOw4rSTLD6AeIKJkqbsrP3sJ2AVA52DPonjMSafmoemFra2E7XJYDqKg4Owq5eDdkvGFVtaECmBGL_HA9D%2DqeNcjoxyI7wqEdUgVfMehur3PZ_ddPmpOrzj3sGft%2D2lP5g6%2DgPUWi4p_3yWHIOavUBuBFiz4Ajp2QqHIu8rZmudsGxcRFH8E25nIu2JvGZ9PG9vtopTZllKRvcJh5uLjhbAp1U8Rp_oBqlOXNJVXaUoIaklJmdSrfS8tbGKOAzNBuzHfcUIJvIDBPS0J7993t9n0vGZQbrg47HabKmlcK0uYq3h8P4_NV2e%2D7428n9dkb1oY7OU6S3xqlLN4wpixDKKz5vFhWCfWdQPkOdoYvTmRFb0VNuTtuO_sKIcGPuta0TbUJQ1yhqHFzE0n_xiiL3p4NQHTNqTRagekMUApmc4D1M63VLk4Banm7Dy2mDFg1lbVYLGVUZTUZA3E1%2D%2DjCcwXlwYwCr2rRLqC_Mha0Vcu7c_1fJeU8lGYUCxirTGPvd0WJfXJ7HAAlntgzyhVe7p4Qlsi38oDhFDX3dm9xkdGp%2DOjG%2DTqGTxPShq8O_b42EVTAHBmJshWuoI7vFJVoNtTMqg01fmhzZ5g%26u%3DaHR0cHMlM2ElMmYlMmZ3d3cucGFydHppbGxhLmNvbSUyZmNhdGFsb2clMmZrYXdhc2FraSUzZm1zY2xraWQlM2RiNGI2MjBkMTM3NmIxOTZkMDI5YTQzMTdhMmViYzMxMCUyNnV0bV9zb3VyY2UlM2RiaW5nJTI2dXRtX21lZGl1bSUzZGNwYyUyNnV0bV9jYW1wYWlnbiUzZFROVF9UZXh0JTI1MjAtJTI1MjBPRU0lMjUyME9ubHklMjZ1dG1fdGVybSUzZGthd2FzYWtpJTI2dXRtX2NvbnRlbnQlM2RLYXdhc2FraQ%26rlid%3Db4b620d1376b196d029a4317a2ebc310&vqd=3-335767801595712138308512653986279609143-39501281590554844159392412597176649425&iurl=%7B1%7DIG%3D6E61F7E17B2B4D9C8FB05DDB7D2FB137%26CID%3D0E29E703890A621406C0F59F88EC63A5%26ID%3DDevEx%2C5045.1

 

[genel]

There is also a possibility someone advanced the timing.

 

[Porky]

Retarding the timing is what normally makes an engine run HOT!

 

[allanpresley8]

Removed every mechanism that is connected to the engine with regards to water passages, the only part l didn't remove is the connector hose between front and rear cylinders still no thermostat.

 

[allanpresley8]

Removed every mechanism that is connected to the engine with regards to water passages, the only part l didn't remove is the connector hose between front and rear cylinders still no thermostat.
View attachment 78037
View attachment 78038
View attachment 78036

Everywhere possible??? A GOOGLE check found many topics about your thermostat:

View attachment 78029

https://duckduckgo.com/y.js?ad_domain=partzilla.com&ad_provider=bingv7aa&ad_type=txad&eddgt=Ay2ynD6ba6ecFtaN9EhR7Q%3D%3D&rut=49c83130b2aa12880564d90c82de2faf6fcb6da2862b8818740d09c4f2438222&u3=https%3A%2F%2Fwww.bing.com%2Faclick%3Fld%3De8oGeNNCVOJZ5aHYgy4MHzfzVUCUx8kaxY%2D0oKtyKF_FkHLadREoyjKk_bHu05vLkPOux_Qyijdw78ihO0IV%2DumKIDq9mJqdyAFfO_vHTe0qtEdreoCT6e0gl9ieNzLHVSVgT1uZLqjIMJy4Be%2DftSlmQPh0w25CzgONeOw4rSTLD6AeIKJkqbsrP3sJ2AVA52DPonjMSafmoemFra2E7XJYDqKg4Owq5eDdkvGFVtaECmBGL_HA9D%2DqeNcjoxyI7wqEdUgVfMehur3PZ_ddPmpOrzj3sGft%2D2lP5g6%2DgPUWi4p_3yWHIOavUBuBFiz4Ajp2QqHIu8rZmudsGxcRFH8E25nIu2JvGZ9PG9vtopTZllKRvcJh5uLjhbAp1U8Rp_oBqlOXNJVXaUoIaklJmdSrfS8tbGKOAzNBuzHfcUIJvIDBPS0J7993t9n0vGZQbrg47HabKmlcK0uYq3h8P4_NV2e%2D7428n9dkb1oY7OU6S3xqlLN4wpixDKKz5vFhWCfWdQPkOdoYvTmRFb0VNuTtuO_sKIcGPuta0TbUJQ1yhqHFzE0n_xiiL3p4NQHTNqTRagekMUApmc4D1M63VLk4Banm7Dy2mDFg1lbVYLGVUZTUZA3E1%2D%2DjCcwXlwYwCr2rRLqC_Mha0Vcu7c_1fJeU8lGYUCxirTGPvd0WJfXJ7HAAlntgzyhVe7p4Qlsi38oDhFDX3dm9xkdGp%2DOjG%2DTqGTxPShq8O_b42EVTAHBmJshWuoI7vFJVoNtTMqg01fmhzZ5g%26u%3DaHR0cHMlM2ElMmYlMmZ3d3cucGFydHppbGxhLmNvbSUyZmNhdGFsb2clMmZrYXdhc2FraSUzZm1zY2xraWQlM2RiNGI2MjBkMTM3NmIxOTZkMDI5YTQzMTdhMmViYzMxMCUyNnV0bV9zb3VyY2UlM2RiaW5nJTI2dXRtX21lZGl1bSUzZGNwYyUyNnV0bV9jYW1wYWlnbiUzZFROVF9UZXh0JTI1MjAtJTI1MjBPRU0lMjUyME9ubHklMjZ1dG1fdGVybSUzZGthd2FzYWtpJTI2dXRtX2NvbnRlbnQlM2RLYXdhc2FraQ%26rlid%3Db4b620d1376b196d029a4317a2ebc310&vqd=3-335767801595712138308512653986279609143-39501281590554844159392412597176649425&iurl=%7B1%7DIG%3D6E61F7E17B2B4D9C8FB05DDB7D2FB137%26CID%3D0E29E703890A621406C0F59F88EC63A5%26ID%3DDevEx%2C5045.1

if the ignitor is malfunctioning will it cause the engine to advance and retard causing the engine to overheat to the point where you cannot sit on the bike.

 

[DannoXYZ]

Did you back-flush radiator? Sludge in radiator will slow down flow and cause overheating.

Also did you answer question about fan? Does it turn ON when radiator gets too hot?