As most know, I just installed the 351 kit, and just took her out for her first ride following BB instructions.

I never really noticed how hot she got before the install, so I'm just curious, fan never came on and light didn't come on, but head was too hot to touch. Rode about 8 miles. Running motu motocool.

Do none 351 bikes run that hot?

Just don't want to cook it.

Thanks!

 

I've honestly never tried to touch the head after running the bike, even for a few minutes - I assume I'd get burned...I would suggest that with the stock setup the head would be way too hot to touch as well.

If the fan and/or overheat light aren't coming on, I don't think it's a problem (assuming that the thermostat and temp sensor are working properly.)

 

Agreed, even the clutch cover will usually get too hot to touch.

No fan no problem.

 

Perfect!

Thanks again guys!

 

Never noticed a difference with mine after install but it was (and probably still is) slightly on the rich side. If I remember correctly you are running a pumper also??? Depending on the jetting it may be a bit lean? This would cause it to run hot, header would be extremely hot and lots of contraction on shut down (metal pinging). Did you remove snorkle or airbox lid also? How does she feel so far? You ARE gonna love the newfound torque!

 

Pumper not installed yet, still the cvk which was already jetted richer. Just wanted to get it broken in before it gets too cold to ride, then pumper gets thrown in.

Was some pinging after first start, but nothing really that over noticed since. Put 40km on it and plug is only slightly black, nothing white.

Rad hasn't boiled, nor has fan come on, but can see the heat waves off engine and exhaust, but it is freaking chilly out now.

Snorkel is removed. Haven't really opened her up yet, as still breaking it in. Can definitely feel it tho!,

 

Here is something to think about - uniform cylinder temp by having the ability to circulate coolant through the cylinder and head when the thermostat is closed. My brother got me on to this. It made total sense to have the thermostat bypass before the thermostat fully opens, to keep uniform temperature all around the cylinder. It won't always run at higher temps in cooler weather, thus the thermostat may range from closed to full open and anywhere between. That makes having the bypass make sense.

The darn thing just has a stupid name - Thermobob - but it makes total sense considering automobiles use a bypass to allow the coolant to circulate adequately through the block when the thermostat is closed.

The 351 having a bit smaller water jacket volume may benefit even more than the stock engines. Read up on it.

 

Cool, thanks. I knew he made them for the klr650, but wasn't aware he had them for the klx. Added to the list!

 

So got a temp gun on her. After about 8-10 mins idling.

Head is 145F
Header(at front curve) is 302F

Actually sounds kinda normal to me?

 

You could compare upper and lower cylinder temps to see how uniform too.