CT70 K0-oil leaks around head gasket

[Meangreenhk0]

My newest purchase K0, 3 speed ruby red, runs strong >40 mph with a 15/35 sprocket combo (might change to 14/35), set valves to .002, timing to .014 of the points, does not smoke.

Noticed red RTV as well as a little oil around the head gasket. It has not actually dripped oil on garage floor but is a little wet around the head. I have not tried to re-torque the head yet.

Can I just pull the head and replace the gasket? If it runs well, keep it simple, or while I'm in there do piston and rings?

Does this leak from the head gasket compromise oil pressure and warrant parking the bike and dealing with this immediately? Or, is it OK to continue to ride, while keeping an eye on it and checking the oil level?

Thanks,
Christopher

 

[69ST]

I have a feeling that this is your oil-consumption issue. RTV, on these engines, usually has me thinking "oh shit" Someone has been into this engine and was too cheap/lazy/uniformed to replace the headgasket & O-rings. $10 worth of parts and a LOT of meticulous cleaning will probably set things right.

 

[Meangreenhk0]

Yeah, I agree and share the same sentiment. I assumed by the red color it was RTV. I heard using RTV is usually not a good thing, but can you explain why?

Should I not ride it until I replace the gasket risking catostaouphic failure? Does small amounts leaking oil from the head decrease oil pressure or cause a loss of compression,etc?

 

[cjpayne]

I would definitely take the head off and clean ALL that rtv out of there. RTV can cause nightmares when not used properly. Especially the little "strings" of it and tiny bits that get into everything. I would pull the clutch cover and check the oil screen and spinner too.

 

[Meangreenhk0]

Good news, on closer inspection there does not appear to be RTV. The head bolts were loose. I torqued the head down and low and behold...no more head gasket oil leak.

I got the plates and registration recently so I was able to test the bike outside the neighborhood. The bike runs like a champ and, in addition to road testing, I actually took it on some trails today! What a blast!

I changed the oil for good measure, still with the occasional slip when kickstarting and I can't quite tell if the clutch is just maybe starting to slip under load. This bike has K0 motor (2100 miles) but, if you recall, the PO installed new 15/35 sprockets and a new chain. It is torquey and fast. It quickly hits 43 mph no problem and 45mph crouched down on the flats! (I'm 5'10 and 180 lbs) I was surprised that the top speed would reach that high with that gearing.

I anticipated the fast acceleration and maybe a disappointing 35-38mph top speed. I had actually bought a 14 tooth front sprocket to get back to stock gearing. However, I think I like the way this gearing feels. Plus it's an easy/quick switch of the front sprocket to get back to stock ratio, without having to yank the rear wheel and waste a new chain. In my mind, It might be ideal to put a 35 tooth rear on the K0s, if only for a quick change gearing option, right?? Torquey gearing today, top end speed ratio tomorrow, easy peasy.

These bikes always surprise me. Does this performance seem right to you with this gearing? Or, would you think maybe it has been bored over? Any thoughts what the top speed would be if I went to a 14/35 (stock equivalent), if I'm already hitting 43-45mph?

My inquisitive mind is always working and I was wondering; could I just unbolt the head "plate" with the engine mounted on the bike and be able to easily read the top of the piston? Thereby, to see if there is a .50 or 1.00 over looking back at me? If so, would you need to drain oil or any other tips/precautions?

Thanks,

Christopher

 

[cjpayne]

If it's running great, then leave well enough alone. "If it aint broke, don't fix it."lol
On my HK1 I had, I ran 14/35 with no problem, but the primary gears are different than a 3speed(pretty sure).

 

[OLD CT]

The head plate will only reveal the valve springs and rockers. The whole head would have to be removed. In other words, not worth it.
That bike is running good.

 

[Meangreenhk0]

Doh! not sure what I was thinking. Of course, the head would need to be removed. I said my mind was always working...just not very well in this instance.