|
|
Post by Fox on Dec 7, 2011 19:18:04 GMT -5
This project has been sitting collecting dust since April so today I finally decided to try screwing with it some more. Just for shit's and giggles I put the stock cylinder back on it and it still ran crappy. The damn thing starts up and idles perfectly. Give it gas and it will rev good up to about 1/3 throttle and then it starts to bgog and spit gas out the back of the carb. If I partially block the carb throat with my hand it will rev up really high but erratically. Like it's missing.
After that I put the BBK back on and I tried several stock carbs and a 20mm carb and the damn thing does the same thing with all of them so I'm starting to think maybe it's a stator or CDI issue. Anyone agree it might be electrical?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 7, 2011 19:33:06 GMT -5
sounds like timing not advancing. got a new cdi to test on it?
|
|
|
|
Post by Fox on Dec 7, 2011 19:48:31 GMT -5
Unfortunately I sold all the CDI's I had to customers. I'm gonna order a couple and a stator and see what happens.
The reason I think it's a spark thing is because The damn thing ran great for a day, I parked it for a week, went out to go for a ride and when I fired it up it ran like crap. I didn't change anything but I did remove and replace the battery cause I needed it for testing another scoot. Can swapping a battery fry a CDI?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 7, 2011 20:19:24 GMT -5
anything is possible when it comes to electricity/electronics.
|
|
|
|
Post by Fox on Dec 7, 2011 20:27:37 GMT -5
Actually I lied. I have 5 CDI's (2 small and 3 large) out side none of which work on this scoot. I can't tell if they are AC or DC so I really don't know what to buy. I used to have so many CDI's sitting around I would just plug one in til it worked never knowing if it was AC or DC. If it worked it worked. I wish they stamped AC or DC on the fuc*ing things!  Really I wish I wasn't such an electrical retard. How do I check if a CDI is AC or DC with a volt meter? |
|
|
|
Post by 190mech on Dec 7, 2011 20:28:56 GMT -5
When Brent was crazy enough to mess with a QMB,he had a similar experience..Turned out the timing was waaay retarded,think it was the woodruf key slot incorrectly machined...Check it with a timing light after making sure the marks on the flywheel are correct with piston travel..His cure was remove the key and index the flywheel to true TDC,,that made it more better!!
|
|
|
|
Post by Fox on Dec 7, 2011 20:34:11 GMT -5
|
|
|
|
Post by 90GTVert on Dec 7, 2011 22:13:47 GMT -5
If it ran well for a long time, it probably isn't the flywheel. I did run with no key at all till I got a new flywheel for convenience (much easier to jet pop it on and off than worry about lining it up). If you have a timing light, it's pretty easy to see if it is or isn't advancing.
|
|
|
|
Post by Fox on Dec 7, 2011 22:30:15 GMT -5
Yeah It ran perfect for 20 minutes after I first installed the BBK so it's not the flywheel. I just ordered 2 AC CDI's from scrappy but I could get a timing light tomorrow from HF. There's two on there website. A $20 and a $35 one. Will the cheapy one work okay or should I get the other one? www.harborfreight.com/catalogsearch/result?keyword=Timing+Light |
|
|
|
Post by 90GTVert on Dec 8, 2011 1:14:05 GMT -5
The $35 light will let you dial in the timing. You can change the dial position so you just look at a TDC mark on the flywheel instead of needing to guess at where the timing is or mark it to see timing. If you only want to see if it's advancing, the $20 deal will show you that. If you wanna see where the base is and where it's advancing pretty easily spend $15 more. I've never used the HF one, but after owning both standard and adjustable lights, I greatly prefer the adjustable timing lights.
|
|
|
|
Post by Fox on Dec 8, 2011 2:31:44 GMT -5
I think I'll just let it sit on ice til the CDI's arrive. Inside I feel like I should hurry and get it done but in reality there's no hurry but I wanna feel the power of the engine. All I got was a teaser ride and then it started malfunctioning dammit!  |
|
|
|
Post by Fox on Dec 11, 2011 14:10:30 GMT -5
Got the new CDI's from scrappy and it's still doing the same thing. :banghead:
The only thing I haven't tried is a new stator. The one on there is the original one that I swapped out after I changed engines so it's at least 6 1/2 years old with a lot of time on it. I sure hope it works cause If not it'll be my second BBK failure making me 0 for 2 and that's a lousy record.
|
|
|
|
Post by Fox on Dec 11, 2011 17:12:52 GMT -5
Found a couple different stators out in the shop. Tried them both. Same results. I'm so done with BBK's This engine ran fine before I messed with it and now it's friggin dead. What a waste of time and money. :bfg:
I have another stock short case I'm going to try with the same stators and CDI's I tried already. If it runs okay then there's got to be something mechanical going on with the BBK engine.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 11, 2011 17:33:15 GMT -5
still a 105 main? my daily driver is the same setup with a 95 main in summer. 98 in winter. 3500 miles so far. 105 sounds rich to me.
|
|
|
|
Post by 90GTVert on Dec 11, 2011 17:59:32 GMT -5
Found a couple different stators out in the shop. Tried them both. Same results. I'm so done with BBK's This engine ran fine before I messed with it and now it's friggin dead. You've done stock replacement top ends before. A BBK is basically the same, just needs carb and roller tuning usually. If all else fails, forget there's a big bore kit on it for a moment and think of it as stock if that helps. You've pretty much eliminated the cylinder, piston, and rings because you swapped the stock setup on and it ran the same. That should have eliminated any concerns related to the BBK in fact. |
|
