|
Boom
Jun 28, 2021 8:10:55 GMT -5
via mobile
Post by benzee on Jun 28, 2021 8:10:55 GMT -5
So, 50cc TaoTao, BBK, just installed new 20mm carb. Haven’t tuned yet but ran fantastic out of the box for 3 days. Heading to work this morning, she sputtered for a second, then ran fine. 2 minutes later “boom” under acceleration, dead silence,engine off. Pulled to the shoulder and waited a second. Started and idled but cut off on acceleration. Well, I know what I’m doing tonight! Any thoughts would be appreciated. Thanks
|
|
|
Boom
Jun 28, 2021 11:17:22 GMT -5
via mobile
Post by scooter7878 on Jun 28, 2021 11:17:22 GMT -5
Well sry to say but it sounds like ur gonna be pulling the top of the motor apart I'd start with the valve cover and see what u got there , timing chain ect many check the flywheel make sure it didn't loosen up but I'll be honest if u didn't get it and it was running lean u may have I issue. If u have a compression tester I'd test compression before anything
|
|
|
Post by benzee on Jun 28, 2021 12:03:29 GMT -5
Sounds like a plan. Had a little hope when she fired back up but I think your right. On to harbor freight for a compression tester. Wasn't like I wasn’t gonna have to have one anyway. Thanks
|
|
Deleted
Deleted Member
Posts: 0
|
Boom
Jun 28, 2021 12:37:51 GMT -5
Post by Deleted on Jun 28, 2021 12:37:51 GMT -5
Grounding or carb tuning. Check plug.
|
|
|
Boom
Jun 28, 2021 16:24:34 GMT -5
via mobile
Post by scooter7878 on Jun 28, 2021 16:24:34 GMT -5
Let me know how u make out
|
|
|
Boom
Jun 28, 2021 19:22:16 GMT -5
Post by aeroxbud on Jun 28, 2021 19:22:16 GMT -5
A few people have said the harbor freight compression tester isn't very reliable for small engines. 🙈
|
|
|
Boom
Jun 29, 2021 18:27:31 GMT -5
via mobile
aeroxbud likes this
Post by benzee on Jun 29, 2021 18:27:31 GMT -5
Yea, harbor freight is what it is,I know. I own there torque wrench. Check that calibration for sure! Mine was 9 lbs off. Just trying to get an idea of what I’m looking at. Trying to get up the motivation after 10 hrs on the grind but I’ll post what I find especially if it helps someone else. It was a sweet 3 days but It’s what I get for not doing a proper tune immediately. Spark doesn’t look bad. “Nurse, scalpel “!
|
|
|
Boom
Jul 3, 2021 12:05:18 GMT -5
via mobile
Post by benzee on Jul 3, 2021 12:05:18 GMT -5
So, compression test was 60psi, pulled her down to the piston and removed piston. My problem is I don’t see the problem. The rocker arm on the intake side was stiff with restricted movement. Will remove it to check for a burr. Very slight ware on rocker arms. Nothing looks that out of the way even the rings. Cleaning off carbon which wasn’t as bad as expected. Tell me what I’m missing. Otherwise plan on installing a new set of rings? Can send pictures
|
|
|
Boom
Jul 3, 2021 16:12:48 GMT -5
via mobile
Post by scooter7878 on Jul 3, 2021 16:12:48 GMT -5
Do another compression test and note compression. Than put a little oil down in cylinder through plug hole and do another compression test if it compression comes up a good bit more u got a ring issue if compression does not come up u got a valve train issue. U can also put motor on tdc and use the compression adapter and a air compressor that makes at least 100 psi connect the air hose to the adapter in the plug port and listen where the air is hissing from if u hear air hissing from exhaust u got exhaust valve issue if u open throttle and hear hissing from carb u got a intake valve issue if u remove oil dip stick and hear from crank case u got leaking rings or a piston issues the motor has to be top dead center or a easier way remove rocker studs where u would adjust valves from so the rockers can't open valves when u put pressure into cylinder the crank may turn a bit if u remove rocker adjustment it doesn't matter where crank is if u have rockers in and motor on tdc u may need to hold crank from turning bc the cam needs to be on time otherwise it can be holding valves open and give a false diagnosis
|
|
|
Post by benzee on Jul 3, 2021 17:10:26 GMT -5
Just got the master class. DUDE! Thanks.
|
|
|
Boom
Jul 3, 2021 22:04:39 GMT -5
via mobile
Post by scooter7878 on Jul 3, 2021 22:04:39 GMT -5
Lmk how u make out
|
|
|
Boom
Jul 13, 2021 10:46:03 GMT -5
via mobile
Post by benzee on Jul 13, 2021 10:46:03 GMT -5
Question. Intake side of rocker arm is very stiff and hard to move. Tried to loosen. When I rotate the bolt it loosens but then when the U notch is lined up it tightens up again. How can I remove that bolt so I can see what’s going on? If not I’m into a new rocker arm assembly. Pulled the new carb and found the pilot jet was # 28. Never saw one smaller than 30. Might be why she popped in the first place. Everything else looks fine. Don’t have an air compressor to test with but when I cleaned the head I flooded it with carb cleaner, no leakage around valves. If I can resolve the rocker arm, I’ll reassembled and hope for the best.
|
|
|
Boom
Jul 13, 2021 14:18:22 GMT -5
Post by jloi on Jul 13, 2021 14:18:22 GMT -5
pix?
|
|
|
Boom
Jul 13, 2021 14:23:36 GMT -5
via mobile
Post by scooter7878 on Jul 13, 2021 14:23:36 GMT -5
If ur talking Abt the pin that slides through the rockers it's not threaded I usually find some type of screw that threads into the center and use pliers to pull the pin out if it's tight that's the reason the rocker is tight to be honest I'd just buy a new one there cheap enough but a pic of what exactly ur talking Abt would help also
|
|
|
Boom
Jul 13, 2021 14:25:48 GMT -5
via mobile
Post by scooter7878 on Jul 13, 2021 14:25:48 GMT -5
Did u do the wet compression test ?
|
|