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Post by buzzard82 on Feb 20, 2020 5:03:22 GMT
Got the flywheel off, somebody has been in there before looks like one condenser been changed and one original.points look like new. Ordered 2 new bosch condensers. To be continued.
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Post by doolittle on Feb 21, 2020 0:04:23 GMT
Buzzard, if that thing don't have Bosch points in it, you better get them ordered too. Anything aftermarket is junk from my experience.
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Post by buzzard82 on Feb 21, 2020 1:39:31 GMT
Buzzard, if that thing don't have Bosch points in it, you better get them ordered too. Anything aftermarket is junk from my experience. Agreed never once had luck with aftermarket ignition parts. My dad had a 72 lynx 340 always popping out carb/missing. Had flywheel off many times. Changed points and condensers with jobber many times over a bunch of years. Never ran right until put in OEM points/condenser. Knock on wood ran has ran good for over 5 years. Brother had a 5500 mx that the cdi gave up tried a Kimpex it ran, but not like it used too. Put a new nippendenso on and back to normal. When I was a kid i had an eltigre 5000. Went threw same thing with kimpex cdi's and coils. Back them before internet days when parts were discontinued trying to find oem used was like driving a boat with no compass.
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Post by olyman on Feb 21, 2020 23:07:09 GMT
Found the timing spec's for the 775:
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Post by olyman on Feb 21, 2020 23:22:55 GMT
....Still looking for the readings you'd get if you have a capacitor function on your meter... Found in the old 70-73 shop manual that if you can test capacitors with your meter (some nicer meters nowadays have cap testing capabilities)... you should expect to read 0.26 to 0.30 microfarads (all models). Some of those fancy old bombi testers could read capacitance as well.
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Post by buzzard82 on Feb 22, 2020 17:31:48 GMT
....Still looking for the readings you'd get if you have a capacitor function on your meter... Found in the old 70-73 shop manual that if you can test capacitors with your meter (some nicer meters nowadays have cap testing capabilities)... you should expect to read 0.26 to 0.30 microfarads (all models). Some of those fancy old bombi testers could read capacitance as well. So with meter hooked up after cranking over that should be the reading? Btw you guys are awesome as usual 👍
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Post by dando127 on Feb 22, 2020 18:57:17 GMT
I had a similar issue this month with my 318. It would fire a little bit, then nothing. Pull the plug and its wet. I checked all the wiring and then I ended up with no spark at all. Yesterday I changed the ignition coil with an aftermarket one, and I have spark again. I still need to button up all the wiring and give it a test drive, but I think I have it figured out.
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Post by olyman on Feb 23, 2020 2:54:29 GMT
To measure the condenser you'll need it to either have the wire removed, or the point held open. You don't want to have an electrical path between the two contacts of the condenser. You will see what I mean if you look at the wiring diagram for the sled.
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Post by buzzard82 on Mar 5, 2020 19:12:59 GMT
I had a similar issue this month with my 318. It would fire a little bit, then nothing. Pull the plug and its wet. I checked all the wiring and then I ended up with no spark at all. Yesterday I changed the ignition coil with an aftermarket one, and I have spark again. I still need to button up all the wiring and give it a test drive, but I think I have it figured out. Your Ignition coil problem was it always with 1 side? We put in 2 new condensers and same thing.
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Post by dando127 on Mar 6, 2020 12:38:31 GMT
I should have updated a little sooner. The coil fixed my problem for about 15 minutes. I made it up the street, and had to walk to get the truck to carry it home.
My new flywheel puller arrived today, and Bosch points and condenser are on the way. Hopefully that solves it, but who knows!!!!
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Post by buzzard82 on Mar 6, 2020 14:42:13 GMT
Looked under the intake and the gaskets to the head were homemade out of plastic. Threw that away and put on a set of cork gaskets. Same thing. Soaked it with either and carb cleaner while running and nothing. You can even squirt into the pto carb and doesn't change it.covering the carb boot no change. Inline spark tester shows spark. At idle maybe a little weaker than mag side.
Have another whole stater plate from a 640.Will try changing the whole thing.
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Post by olyman on Mar 6, 2020 14:49:38 GMT
Have another whole stater plate from a 640.Will try changing the whole thing. Thats a good idea at this point. Could be something you cant see like a bad wire or connection at a junction point or between the stator plate and the coils. How does the timing look? HAs it ever fired on that side recently?
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Post by buzzard82 on Mar 6, 2020 16:02:22 GMT
Have another whole stater plate from a 640.Will try changing the whole thing. That is a good idea at this point. Could be something you cant see like a bad wire or connection at a junction point or between the stator plate and the coils. How does the timing look? HAs it ever fired on that side recently? Never played with the timing on it. When i first got it it ran good.well as good as these 775s do, as always seems like they like to foul/pop on and off 2 cyls sometimes. Any other one ive seen all seemed similar lol. It has progressively gotten worse past few years.it hadnt run in two years. I assumed was diaphragms/plugged low speed jet holes in that pto carb.had the sled over 10years never done the carbs just stabyl and drain fuel each year.i figured they were due to be rebuilt.at same time the carbs were not correct carbs, so i bought two 20A's and put new diaphragms in took welch plugs out and and cleaned low speed holes and.new welch plugs back in. Used the needle and seat from old carbs as they had the Y hook on the needle. When i started it this year for first time with the old carbs it ran better than it had in years (for about 5 mins) Then it started doing what its doing now. On a pass up the driveway the sled lost all the lights and then started on and off 2 cyls again.pto side never as hot as mag. I have yet to put the compression gauge on, but i guess at this point why not. When i got it the pistons and rings were not very old. Myself i have put maybe 10 miles on it since i owned it. It had the factory small 70 grab handle son the rope, so always pulled over like a bear. In all this saga i put on a D handle on it and you can crank it with one arm if you give it a good yank. Ive gone threw 3 starter cups over the years, so its got some compression lol
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Post by olyman on Mar 7, 2020 14:09:24 GMT
Ya from the sounds of it it's not the compression by any means. Would be cool to know what it is just for giggles. But based on what you're saying, something is failing. Could be the main coil but you'd wonder why if it's good enough for the other side. There might be several little things that add up to what you're getting. Something else to consider is the piston being installed the right way. I've actually heard of some engines running when they were installed wrong and others that just won't. Seems far fetched on yours but worth looking into the intake side of the engine to see the skirts in the right place. Even if the timing was good it wouldn't be happy if the slugs were swapped. Putting that stator on from the 640 is going to tell you a lot imo.
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Post by buzzard82 on Mar 7, 2020 21:34:08 GMT
Didn't get to the stator swap yet. Took compression its 175psi each side on a 15year old cheapo gauge. Unplugged the ignition key to rule out other wiring. No difference.
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