2006 TGB R50X "Bat outta Hell"

[ryan_ott]

To check the accuracy of it stick it in boiling water it should read 212. I tried looking back to see if this is a ring terminal under plug or on a cooling fin I didn't see which.. You would see that behavior if on a cooling fin.

[Elektrey]

it's like this except replacing the spark plug washer (was exact same thickness of the washer)


I've got a BR9HS equivalent in there (autolite brand). Will this cause it to run this cold?

[Jwhood]

Spraying starting fluild always doesn't work when checking for leaks especially for me!!

[Chris Cristini]

Jun 29, 2016 15:25:38 GMT -5 niz76 said:

Yep that'll do it. Temp leads are very sensitive and usually don't work correctly when spliced together like that.

I have had huge arguments about that when I was automation maintenance.

[Elektrey]

Just checked it with a digital thermometer I had lying around

__________________ Ambient Air | Cup of Ice
Bike thermocouple 82F 36F
Digital Thermo 81.0F 35.8F


Looks 100% Accurate, within 1 degree.

is this some kind of combination of rich+cold plug+good cooling system ?

I ran for almost 1000 miles the last kit I had with the head turned completely sideways (air not able to run through fins) before it seized. Maybe the cooling is very good? idk

JW whats the best way to check for leaks?



Found this too, which shows if you go too lean you get lower CHT temps. possibly I'm on the very far left of that chart (with an air leak) ?

[Elektrey]

saw this

www.youtube.com/watch?v=zMok2y05jNE

and thought maybe I should try it with the ecig I have haha, thoughts?

I did it and smoke started coming out here:


Like I said before think I am missing a gasket here:


also the throttle cable is cut to fit a certain length idk if that has anything to do with it.

Can anyone confirm if they also have a gasket there (if you have a similar style carb)

Found a rebuild kit for same style carb and it shows the red gasket that I remember (albeit slightly different thickness)



Also another thought, maybe the spark plug coil wire is interfering with the thermocouple cable? I mean if the RPM cable can be wrapped around it to pickup the RPMs could it be interfering somehow?

[Jwhood]

Yeah my carb has red gasket on top of throttle cable cover,were did you blow smoke from,you can use propane to check for leaks,but trust me on these the intake is a bastard I've worked on tgb scooters that's never been tampered with and 75%of the time the hang is from air escaping oil pump side of intake and or crank seals are dry rotting but that would cause hard starts and idle would be wonky as hell!!!

[Elektrey]

blew smoke into the hole where the air filter goes. held the throttle open.

It will sometimes start with no throttle but usually give it a little throttle to start it. once started it idles fine though.


Doubt seals are dry rotting, its pretty humid here and the whole bike is in great shape for 10 years old, nothing else is rotted at all that came stock on it.

Scouring the internet for anyone with similar CHT readings and found this:

modernvespa.com/forum/post1174084#1174084

Also this is pretty close:

modernvespa.com/forum/post1177265#1177265

most CHT talk on the web is about airplanes.

Idk, I think something is interfering with the CHT gauge that is related to the engine RPMs.

When I turn the engine off the CHT shoots up especially if I just rode it around the block and then stopped, goes up to like 260F.

Can anyone see what their CHT values do when they turn the engine off? (after idle/mid-throttle/WOT)

[90GTVert]

Jun 30, 2016 20:22:44 GMT -5 Elektrey said:

Maybe the cooling is very good? idk

If a relatively simple forced air cooling system kept the head under 200F, no one would bother with more complex liquid cooling.

Your temps when you turn the engine off sound better to me. Mine cools pretty quickly when I'm not WOT and temps begin to drop shortly after the engine is turned off. I don't see 50-100F increases when I shut down, so I think you're right that you may have some sort of strange interference.

[Elektrey]

thanks for the input brent, getting closer to the culprit I can feel it.

[Elektrey]

Took the spark plug lead and seperated it from the thermocouple wire a good distance.

Took it out again and it did the same thing, no difference.

Going around 20-30mph it settles like around 140 150F, then if I stop it rises and settles to 180F over maybe 15 seconds, then if I turn off the engine completely it rises and settles to 215F over like 20-25 seconds.

weirdest thing.

[Elektrey]

Guess my next step is to isolate the problem. Gonna run leads from my car battery to the gauge and then idle the scooter and compare that.

[Elektrey]

so I moved into my new place and have the scooter here and I still can't figure out this CHT gauge.

Is there anyone that can help me out? I'm completely lost as to why it's not being accurate, and I would like to know the CHT so I don't seize. ordering a different sensor setup is kind of out of the picture since I already cut a hole in the plastic to put the display in this one.

[Elektrey]

So I took my scooter to school (roughly 3 miles, some 40mph some 45mph some 30mph) and on the way back on a stretch I was doing upper 40s on the bike suddenly just lost power and the tach went to 0 then up to around 7k for a brief second then stopped.

I took it off the road immediately and tried to start it up again and it started right up and drove off fine.

Was this a soft sieze? I upped the jetting two sizes recently to make sure it was on the rich side. Maybe it is too rich near WOT and bogs out after a while?

[90GTVert]

The tach should work fine during a soft seize, though I wouldn't rule one out from the rest of the description. Maybe there was an issue with the ignition system? Loose connection?