how's my jug looking?

C

chris8686

New Member
Part of my routine maintenance is pulling the head and checking out my bore and I've noticed these deep gouges on the clutch side of the motor. I can feel them with my finger nail. The brown mark seems like it is just carbon and it cleans off. Should I continue running this cylinder or grab another off the shelf? This motor currently has 1400 miles. It is currently running opti2 at 60:1.

I just moved to another town and I want to make the longer commute on this bike. It will be a 35 mile round trip daily. Before it was only making a 10 mile round trip.
 

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Definitely got some scratches starting there but most likely still ok as long as you're not losing compression... this type of wear is usually from stuff slipping past your air filter so if you live or ride in a dusty environment it might be time to upgrade your air filter to something that can stop those particles from getting in like a good foam filter with the right sticky type filter foam oil. K&n type filters can let some stuff get past the filter in more dusty conditions so in these cases you may need to switch to a filter that's a little more effective in these areas. There are also a lot of these k&n type filters that are sold dry and need to be oiled to prevent tiny particles from slipping by.
The stock filters really don't protect very well against this either so if your running a stock type filter you may want to consider upgrading to an oiled cotton gauze type or even better, an oiled foam type filter.

Like I mentioned already about the jug, as long as you still got compression it should still be ok but keep a close eye on it, but if you got a spare jug and set of rings I would go ahead and swap them out.
Also if you're running at full speed most the time and you have upgrades for more rpm you maywant to add just a bit more oil to your mix... the Opti2 works great at 50:1 or even 40:1 if you run full out on your commuters for longer periods of time.

Did you do a compression check before taking off the head? And if so, what did it read at?
 
I don't have a compression tester. I have not noticed a loss of any power. I do have a foam k&n style filter oiled with maxima filter oil. I was running opti2 at 80:1 or 1.5oz per gallon in this motor and one of the main bearings went bad soon after. Running it at 60:1 makes a lot of carbon and everything is very oily.
 
I am going to buy a compression tester and after I get a reading off of it I intend to keep running this top end until it gets much worse.

Who out there is using a harbor freight compression test kit? Is it accurate and would you recommend it? If there is a different kit you are using and would recommend please drop a link to it.

I will keep posting as I accumulate more miles and post pics as I go.
 
I ended up buying a Bosch FIX7828 compression tester today. Really nice quality kit for $30. I did a compression test on both of my bikes. Both of my bikes got a reading of 100 psi. Both the engines are Dax gen IV motors. Not sure if it the 38 or 40mm stroke motor. It has the short rod low wrist pin hole. They are both fitted with 7.0cc Fred head's.

So I guess the end result is that the scoring on the cylinder is not dropping the compression and I just have a low compression setup.
 
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