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Post by bigkahuna427 on Oct 28, 2011 6:55:24 GMT -5
There is an Ebay listing for a 100cc big bore kit $75 shipped to my door... The gears are turning  its a 50mm kit (82cc) but they call it 100cc. a 95 main jet in the stock 18mm carb works well with it. The larger valve kit was only $10 bucks more. Including the head and valves I thought this was pretty darned cheap. My guess is this is not a performance kit just a larger displacement kit. In effect I would have an 80cc engine not an 80cc high performance engine. Your thoughts? |
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Post by speedy1125 on Oct 28, 2011 9:07:42 GMT -5
its a 50mm kit (82cc) but they call it 100cc. a 95 main jet in the stock 18mm carb works well with it. The larger valve kit was only $10 bucks more. Including the head and valves I thought this was pretty darned cheap. My guess is this is not a performance kit just a larger displacement kit. In effect I would have an 80cc engine not an 80cc high performance engine. Your thoughts? stock head milled for 50mm jug that kit is. add a Uni filter, 95 main and performance cdi to that and your low-midrange torque and acceleration will be greatly improved. top end will be about 50mph for a 180lb rider on flat roads with no wind in cool weather. cruises at 45 easy. gas mileage is nearly what stock is. Get the hoca 50mm gasket set from parts for scooters, you might need to use 2 base gaskets i can send you one of my complete kits for $165 shipped.  also you said the bigger valve head kit is only $10 more. the 69mm valves are not bigger in diameter, the stems are longer. its for motors that have 69mm valve rocker arms as opposed to 64mm. |
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Post by bigkahuna427 on Oct 28, 2011 10:59:06 GMT -5
Might be something I would consider over the winter. For now I just need to see this thing run so I can access it a bit. Either way I will tear it down to the frame and go through it and also address some of the unfortunate styling...
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Post by speedy1125 on Oct 28, 2011 13:21:02 GMT -5
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Post by bigkahuna427 on Oct 28, 2011 13:21:47 GMT -5
I am now at a point where it should run. I have spark fuel compression but still no run. I have done a little kicking with the kick start and it fires pushing my leg back up. It has even done this slowly positioning the cylinder to the compression stroke before a kick. it seem to be firing too soon. Could this be a preignition problem with the timing being too advanced?
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Post by speedy1125 on Oct 28, 2011 13:30:18 GMT -5
did you have the head off?
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Post by bigkahuna427 on Oct 28, 2011 14:16:56 GMT -5
I have not had the head off. This should be pretty simple..
I have checked valve lash and it was fine. Made a slight adjustment to the exhaust valve.
Pulled the rocker cover off and checked cam timing using both the marks on the engine and then verifying TDC with a screw diver and looking at valve overlap. I just wanted to make sure the flywheel hadn't sheared a key. There were two marks on the flywheel one was TDC the other lined up when the pick up was lined with the stator.
I pulled the exhaust off to make sure it wasn't plugged.
The closest it has come to starting the carb spits fuel out through the air horn onto the rear fender. It is not a flooding bowl overfill condition.
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Post by bigkahuna427 on Oct 28, 2011 14:21:32 GMT -5
Geesh I have almost $10 into this thing with the fuel line filter and an NGK plug. :spark:
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Post by speedy1125 on Oct 28, 2011 14:22:19 GMT -5
Timing should be pointing to the 'T' on the flywheel, not the line beside it. if someone had it apart before you they may have made this common mistake.
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Post by bigkahuna427 on Oct 28, 2011 16:08:34 GMT -5
Valve timing is on. It haa backfired right through the carb. I have had it running now and long enough to adjust idle mixture and speed. Seemed to have pretty good throttle response considering I had the air cleaner off. Then it would just die and not restart. I let it sit and it fired right up ran great.
Then I grab the CDI at part throttle and the engine speed dropped banged it a couple of times then engine died.. Coincidence? Maybe, but I was now focusing on the CDI. I pulled all the terminals out of the connectors and checked them. They all fit tight so I put it back together and hit them with contact cleaner for good measure. I did find a loose connection on the coil and a wire that had been cut and just twisted back together at the CDI. This wire was to the kill switch so even if it open circuited it wouldn't be what I was looking for. The sun is going down and it's getting cold so I am packing in for the night.
I wish I had a CDI right here to try!
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Post by speedy1125 on Oct 28, 2011 16:57:52 GMT -5
Valve timing is on. It haa backfired right through the carb. I have had it running now and long enough to adjust idle mixture and speed. Seemed to have pretty good throttle response considering I had the air cleaner off. Then it would just die and not restart. I let it sit and it fired right up ran great. Then I grab the CDI at part throttle and the engine speed dropped banged it a couple of times then engine died.. Coincidence? Maybe, but I was now focusing on the CDI. I pulled all the terminals out of the connectors and checked them. They all fit tight so I put it back together and hit them with contact cleaner for good measure. I did find a loose connection on the coil and a wire that had been cut and just twisted back together at the CDI. This wire was to the kill switch so even if it open circuited it wouldn't be what I was looking for. The sun is going down and it's getting cold so I am packing in for the night. I wish I had a CDI right here to try! I always keep 2-3 around for diagnosing bikes in on no start problems, first thing i do is plug in a new box |
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Post by speedy1125 on Oct 29, 2011 21:27:43 GMT -5
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Post by bigkahuna427 on Oct 30, 2011 6:41:51 GMT -5
That is a great graph! Brent does such a good job with information up here....
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Post by bigkahuna427 on Nov 15, 2011 20:08:41 GMT -5
Just thought I would update you guys. I have the peace running I have only run it up and down the street at this point but here is what I found to get it running..... My focus was on the CDI I had a CDI that I swapped from a friends scoot and still had the same issues. Sometimes it would run sometimes not but when it didn't run the plug was firing way too early. Sometimes if I was kicking it it would kick back. There were time when it actually fired out through the carb. I found a schematic for the CDI and when checking ohm readings everything seemed to be off. I went to a ground on the frame and found it was attached to a painted lug on the frame. I ground off the paint re-attached the ground and it fired right up. Now I just gotta get his thing to do more that 25MPH. I am 6'3" and 260lbs so I know I am pushing it but it is not running right yet. I think I just need to go for the new carb and call it a day. I think I am just going to sell this thing. I feel like I am sitting on a milk crate with the handle bars against my chest. The Kymco Yup50 I am working on seems so much better and bigger, 12" wheels instead of 10", longer wheel base etc. The quality is also much better......
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Post by Fox on Nov 15, 2011 20:25:22 GMT -5
Nice going on finding that weak ground wire.  Have you tried lighter weights yet? Some 4.5 gram weights might help it get up and go a little better. new carb can't hurt either but you may have to swap jets from the old to the new. Plug color will tell you. |
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