usfmarine
Non-Com
SJA, Scooter Rebellion
Posts: 74
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Post by usfmarine on Nov 18, 2009 2:04:09 GMT -5
Thanks a bunch, those pics show me how far I have to go. You are going to cringe when you see my exhaust port matching hatchet job. So pic one shows my exhaust flange. I never saw the exhaust by itself after my muffler guy installed it so I never saw that he obstructed a lot of the 1 1/4" flange diameter with flux beads. Using my $8.99 harbor freight dremel, I grinded down a bunch of the built up flux. I could have done more, but I did not want to weaken the weld. I grinded down some of those beads at least 3-4mm. Not perfect, but a decent hack job. I just never thought he'd obstruct the pipe by welding it that way! My new ENM tach. Finally got it to work by isolating the excess wire away from the coil. The rest of the photos are from this last Sunday when "Doug in San Diego" and I got together to do the Kliff spring and cam upgrade. I'm on the right, Doug on the left. Don't laugh, here's my hack job port matching on the exhaust. I used whatever tip was on Doug's dremel, then my grinding stone. Head just pulled off. Head after cleaning it up and lapping the valves: This was kind of concerning. Even after I lapped the valves, my small valve looked like this. The other valve had nice crisp silver rings on the valve stem itself, the small valve didn't turn out that way. However, I did the same lapping process for both. Any ideas? After getting everything back together and it running fine, I started to try and rejet for the colder weather. I recently went from a 130 -> 150 main jet. Then today I picked up a 170 main jet. Here's the spark plug with the main jet. I was going WOT and hit the kill switch, then pulled the plug. Look how white it still is! I noticed that one side of the white insulator part of the plug has a very very light brown tinge to it. Does one side of the spark plug being white and the other side light light brown mean anything specifically? I'm open to any advice or comments on the above photos.
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Post by kliff on Nov 18, 2009 7:09:12 GMT -5
Hmmmmmmmm..... typical Chinese quality control. That exhaust valve is not seating properly. The seat surface shold be about mid way towards the outside of the machined area. Yours is just barely on the outside. It's been so hot, borderline cystallization, you're lucky when/if it burns. The alternative is a dropped valve. That's when the head of the valve separates from the stem, usually in the higher RPM ranges, and destroys many parts; head piston, cylinder...MINIMUM.
This is not unusual, and most likely the reason you're NOT getting the performance gain you expected.
Your plug is running a tad hot. .
The porting, not a bad start. Wrong bit, and a cautious heart/hand.... I see where you could get the hang of this. Get the right burs, and practice on something you won't need to depend on.
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usfmarine
Non-Com
SJA, Scooter Rebellion
Posts: 74
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Post by usfmarine on Nov 18, 2009 9:49:16 GMT -5
Hey Kliff, could my scoot being very lean for a very long time have caused my exhaust valve to look like that? I think that's what you're saying. Extreme heat having baked that valve...
If my valve seats are on the verge of going, how do I "re-cut" them? That sounds like a serious non-amateur repair.
So it seems the next step will be to contact a local small engine repair place and ask them if they can "recut my valve seats?" Is this a service you offer Kliff if I have no faith in the locals? I really would not like to have my valve come apart and bounce around in the combustion chamber.
So by looking at my plug, you think I need to go to a 180 or 190 from my current 170? Remember, just a couple of days ago I was at a 130 with this thing. That's how lean and hot I had it before. In the summer, 130 had the plug nice and gray. Now it is snow white.
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usfmarine
Non-Com
SJA, Scooter Rebellion
Posts: 74
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Post by usfmarine on Nov 18, 2009 11:25:56 GMT -5
Do you think my bad exhaust valve is leaking, thus forcing me to jet so high? I'm about to order a 190 jet, that seems absurd considering a #130 had a nice tannish color to it 6 months ago.
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Post by Rebel on Nov 18, 2009 12:48:18 GMT -5
That valve is about to not seal much at all, when that happens, little to no compression. i think you would save money by getting a new head from ebay, machine shops that could fix the valve are not going to be cheap and pretty certainly more than the cost of a new head. Get a new head, start your porting on it and when it is all done just R&R it. Oh, ya, be sure to check out the valves on it too.
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usfmarine
Non-Com
SJA, Scooter Rebellion
Posts: 74
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Post by usfmarine on Nov 18, 2009 13:16:00 GMT -5
I'm a little confused; it happens easily. If I get someone to recut the valve seats, and I buy a new exhaust valve, that's all I need to do right?
Are you saying that buying a new head is cheaper/easier than recutting the seats and buying a valve? I just want to make sure I understand. Thanks.
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Post by Rebel on Nov 18, 2009 13:42:30 GMT -5
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Post by Rebel on Nov 18, 2009 14:02:06 GMT -5
Also , don't know if you need a "P" head or not.
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usfmarine
Non-Com
SJA, Scooter Rebellion
Posts: 74
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Post by usfmarine on Nov 18, 2009 14:35:01 GMT -5
Hey thanks Rebel. JRR emailed me with the same advice. Cheaper and easier to get a new head that has valves installed instead of trying to resurrect this Mao special I have.
I am going to contact Mike at buggyparts and inquire about his $50 gy6 head. I guess he will port and polish it for $50 more. So for $100, I could get a brand new port/polished head. I know it wont have the perfection we all expect from Kliff, but it'll be better than living on the edge like I currently am.
My scoot is not a "P" thankfully.
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Post by Rebel on Nov 18, 2009 15:54:53 GMT -5
I was thinking about it, if you can happen to get a small engine repair shop to do the work, it might be pretty inexpensive. you might just call around to the local lawn mower shops and ask if they do that kind of thing.
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Post by kliff on Nov 18, 2009 16:01:01 GMT -5
I don't know man.... Looks like Mike and or JRR should take over from here.
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usfmarine
Non-Com
SJA, Scooter Rebellion
Posts: 74
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Post by usfmarine on Nov 18, 2009 18:34:00 GMT -5
Oh no, now i've alienated kliff! Don't go Kliff, I didn't mean it. I still need your advice. If you don't answer my stupid question and if I don't post amateur questions, there isn't a whole lot being posted here at scooter rebels.
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Post by kliff on Nov 18, 2009 20:34:54 GMT -5
.... If you don't answer my stupid question and if I don't post amateur questions, there isn't a whole lot being posted here at scooter rebels. Hmmmmmmm, you think so huh? This is a thinkers site, not a Bull crappers palace..... And like any activity undertaken by those of reason, skill, and experience, many converstaions, plans and builds go on behind the scenes. You were just made privvy to a small portion of what some others have tried their damn'dest to learn. But this thread, was and is, about valve springs, I just sorta got off subject with the porting.... so I cleaned it up a little. Let's stay on topic guys. 3 sets waiting to be built and shipped, come and get 'em!
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Post by Doug in San Diego on Dec 4, 2009 20:21:50 GMT -5
Update on the new A12 and Kliff-o-matic springs Marine and I installed the new springs and cams a few weeks ago. So far mine is running fine. Very clacky, but that is to be expected with the new cam. Power is up (mostly good torque going up hill) I still have a small oil leak after the install. I have not had the time to take it apart to locate the source, but it is not a very big leak (few drop every night) I had to put my OEM airbox back on (UNI fell off and was eaten by rear wheel ) So Im not getting the true MPH yet. So far so good. Not sure why the leak but I'll let you know Springs were very nice by the way Kliff Believe it or nor, I am sorely tempted to have a tiny bit machined off my head (Heard that would make it go like a rocket ) The grass is always greener Doug - Merry XMAS all
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Post by Rebel on Dec 5, 2009 0:10:58 GMT -5
You can up the compression a bit by "milling" the head. You probably won't see it go like a rocket though.
When they mill the head it makes the compression chamber smaller so the compressed gases have less space and get squeezed more in the compression stroke. More compression does help but I don't think you will see anywhere near what you would see if you had your head ported and polished.
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