New Rider
Currently Offline
Posts: 24 
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 22, 2015 11:24:57 GMT -5
Hey gang,
Question for those who have more knowledge about these things than I do.
Put a BBK on my bike. its a 2014 taotao 49cc. since the upgrade there has been more difficulty starting the engine. thought it might be the starter or lack of battery power.
yesterday i put a new clutch on it and some new slider weights in the variator, and after doing it, the engine would not start.
it would turn over half way, but never fully turn the engine over. tried w/ a more powerful battery and same thing. tried a different starter and same thing.
took the plug out and the engine would turn over great. the plug was wet, and looked pretty fugly for only being in 1 day. (changed the plug to an ngk iridium the day before this happened). w/ the plug it will only turn over a half turn
there is too much compression in the engine! it really doesn't help that the kickstarter doesn't work, so I cannot get the engine to turn fully over. my mechanic buddy says that should fix the issue.. but im not sure how it happened in the first place.
from what i read, it sounds like maybe there should have been an thicker or extra gasket on the bottom to decrease the compression.
not sure where to go at this point... would like any advice that you guys can offer.
my mechanic buddy says that for some reason the engine has been sucking in more fuel than it can burn and thats why the compression is so high.
fun facts.. the old plug did not look bad or wet at all.. but a new plug should not be able to change the way the engine is sucking in gas though...
|
|
|
|
Post by scooter on Oct 22, 2015 12:16:16 GMT -5
Hey gang, Question for those who have more knowledge about these things than I do. Put a BBK on my bike. its a 2014 taotao 49cc. since the upgrade there has been more difficulty starting the engine. thought it might be the starter or lack of battery power. yesterday i put a new clutch on it and some new slider weights in the variator, and after doing it, the engine would not start. it would turn over half way, but never fully turn the engine over. tried w/ a more powerful battery and same thing. tried a different starter and same thing. took the plug out and the engine would turn over great. the plug was wet, and looked pretty fugly for only being in 1 day. (changed the plug to an ngk iridium the day before this happened). w/ the plug it will only turn over a half turn there is too much compression in the engine! it really doesn't help that the kickstarter doesn't work, so I cannot get the engine to turn fully over. my mechanic buddy says that should fix the issue.. but im not sure how it happened in the first place. from what i read, it sounds like maybe there should have been an thicker or extra gasket on the bottom to decrease the compression. not sure where to go at this point... would like any advice that you guys can offer. my mechanic buddy says that for some reason the engine has been sucking in more fuel than it can burn and thats why the compression is so high. fun facts.. the old plug did not look bad or wet at all.. but a new plug should not be able to change the way the engine is sucking in gas though... If you have a stroker crank then you might need a spacer/gasket between the cylinder and case. |
|
|
|
Post by lain on Oct 22, 2015 12:21:46 GMT -5
They also have thicker head gaskets, much safer and won't blow out from higher compression like trying to stack those silly paper gaskets will.
Also try to change the wires that go from the battery to the solenoid then to the starter motor with 10 gauge wire, and maybe a fresh battery with higher amperage but not necessary. 10 gauge wire should make that starter motor turn a lot harder than with stock wiring.
|
|
New Rider
Currently Offline
Posts: 24
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 22, 2015 12:49:12 GMT -5
well.. we bypassed the wiring by firing the starter directly (clamping negative jump starter to an engine bolt to ground) and positive on the starter directly and no difference. wanted to bypass the wiring to see if that was the issue.
its the same w/ 3 different starters...
im not sure what a stroker crank is.... put the standard 50mm big bore kit.. did not replace the crankshaft..
seems like im going to need to do something to decrease the compression.. just curious why it acted up all of a sudden...
|
|
|
|
Post by lain on Oct 22, 2015 12:55:47 GMT -5
well.. we bypassed the wiring by firing the starter directly (clamping negative jump starter to an engine bolt to ground) and positive on the starter directly and no difference. wanted to bypass the wiring to see if that was the issue. its the same w/ 3 different starters... im not sure what a stroker crank is.... put the standard 50mm big bore kit.. did not replace the crankshaft.. seems like im going to need to do something to decrease the compression.. just curious why it acted up all of a sudden... Bypassing things doesn't change anything. It is a known fact that after you install a big bore kit you must upgrade the starter wires or this will happen. The thinner wires fry up from trying to push the bigger motor, the wires were NOT designed with the big bore kit in mind, so keep that in mind. Get 10 gauge wires, some terminals, replace the wires, see the difference immediately. |
|
New Rider
Currently Offline
Posts: 24
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 22, 2015 13:53:19 GMT -5
hmm.. just talked to my mechanic buddy.. the scooter is at his shop now...
he says.. i bought the wrong plug, and its messed up the timing.. possibly the cdi.. and that made the engine flood
apparently i got an ngk that has a resistor built into it... and my plug cap has a resistor.. he says that it can cause timing issues and even cdi failures..
says he is positive that the compression is too high due to it sucking fuel, wasn't 100% sure if it was due to airbox issues or what.. but after seeing that it was the wrong plug.. he believes that is the culprit.
|
|
|
|
Post by urbanmadness on Oct 22, 2015 13:59:41 GMT -5
Are you sure you are using the correct plug? The plug may be longer and the piston is hitting it. Try putting the old plug back in.
You may be running two much compression, but I'd be sure to check that plug first, because if it lights off, it will put a hole in that piston or bend something, if it's the wrong plug.
|
|
New Rider
Currently Offline
Posts: 24
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 22, 2015 14:15:32 GMT -5
well it ran just fine w/ the new plug for a day... but then the problems started.
as i mentioned, my friend seems certain that it is the wrong plug.. not due to size.. but due to it have a resistor in it as well as the plug cap.
if that could mess up the timing.. it makes sense that it could make the engine suck too much gas.. and cause the compression..
|
|
|
|
Post by urbanmadness on Oct 22, 2015 15:08:57 GMT -5
I didn't see that it ran for a day on the new plug..... (silly me for skimming)
Ok... I'd pull the head and go with the thicker head gasket like lain was saying (easier then pulling the whole cylinder at this point)... BTW, did you change out the CDI for a racing one? Sometimes they have two much advance and make them very hard to start. Totally agree with upgrading the starter and solenoid wiring. And after running with the stock wire, it would start to break down and act like a resistor, making it harder and harder to start. You are not doing the starter any favors either.
The resistor plug wouldn't make it harder to start in that way (although the spark might not be hot enough). If it was messing with the timing, it would retard it, not advance it.
|
|
New Rider
Currently Offline
Posts: 24
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 23, 2015 8:46:05 GMT -5
ok updates...
its a head scratcher...
so got it to start yesterday jumping it off a vehicle... then got it to start off of a normal battery.. but then after it sat for a while.. it would not start again w/ the starter. the starter would turn a half turn.. stop.. sometimes it would speed up just a bit but would stop.
tried it w/ multiple starters.. same thing. the kick start is essentially broken.. but you CAN get it to crank w/ a little patience..
once it starts it runs like a mad man.. but it really seems like the starter doesn't have enough power to turn over a cold engine fast enough to start it.
so the problem is still that the engine is producing too much compression for the starter to turn. (we have bypassed wiring, know there is spark, know it is getting fuel and air.. (have tried w/ and w/o carb and w/ and w/o airbox)
oh.. and just bc ... turns out the petcock was not working properly.. it was giving fuel but not nearly enough. replaced that.. and obviously that will help things run better.. but it doesn't address the starting issue.
the thing that boggles me.. the bike ran fine w/ the bbk for a good 2 weeks. started fine. why would the compression now be too much for a starter?
why would i need to add the thicker gasket?
could this be a case of the bbk finally be broken in.. the piston seals fully optimal.. and increased the compression just enough that it is too much resistance for a normal starter?
yes i have a mechanic buddy.. and yes i trust him.. itis just.. while i am at work all day.. w/o my bike.. i like to troubleshoot the best i can...
i suppose i am going to have to get a higher torque starter... fix the kick start until i get it.. its just a head scratcher...
edit to add- truthfully it has had some difficulty starting.. but it WOULD start. I am wondering if the compression was right at the end range of the torque on the starter and as the engine has been broken in, it has increased the compression gradually just enough to where its beyond the starters capabilities.. i then wonder if perhaps it is TOO much compression.. i do not want to blow my engine up for sure... my mechanic buddy is extremely thorough when rebuilding.. does not skip the tiniest detail. im thinking he just made me an engine too damn good for my own bike.. haha..
also.. i have the orange cdi.. not the blue racing one. but i have tried a standard ac and dc cdi as well w/ the same results.
second also.. if one is not using wires at all.. (ie hooking directly up to power source via jumpers) how would that change anything. they were not involved in the process. i could understand if the starter worked great directly connected, but not through the wires.. then sure.. replace those bad boys. but if the starter wont turn good w/o any wires aside from jumpers (which i would imagine conduct better than a 10 gauge wire)
i am not in any way saying you are wrong.. simply that i do not understand it. im not dumb, but i am not a mechanic. i would welcome an explanation for this.
|
|
|
|
Post by JoeyBee on Oct 23, 2015 9:38:22 GMT -5
How is your battery? Are you sure it is holding a charge?
|
|
|
|
Post by lain on Oct 23, 2015 9:42:38 GMT -5
How would you possibly jump your scooter without hooking up the jumpers to the positive and negative leads that go to the battery? If you hook up a starter motor to another battery maybe, but I would be worried a car battery would have WAAAAAY too much cca and would push it too hard, but if you are saying you get the same slow push fromt he starter being hooked up to something that would normally make it overpowered and it's still acting up I would say it's the starter motor itself. I mean I have had a half a dozen BBK scooters now over the last summer and everything and some of them had issues liek this and I woudl always replace the wires and motor (with stock motors) and it would start fine, maybe slight hesitation but still start up after one or two rotations.
How many times now have you used a car/larger vehicles battery for jumping? Did you remember to disconnect the battery before hooking the jumpers and did you disconnect the jumpers right away and reconnect the battery? If you don't disconnect the battery you damage it as soon as you hook up those jumper cables, even if you do not try to start it, even if it's just for a second or two, it will cause damage. I have seen many scooter batteries die because of hooking them up to car batteries. The plates in them start drying up and warping immediately, sure you can be super careful but you can't be faster than electricity can you?
|
|
New Rider
Currently Offline
Posts: 24
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 23, 2015 10:08:30 GMT -5
thanks for the replies.
to answer, we have bypassed the wiring and are trying the starter directly by connecting the negative jumper to a screw in the engine (to ground) and the positive to the starter itself. this avoids the wiring completely to troubleshoot to see if it is the starter itself or the wiring.
as to jumping it.. twice. followed standard protocols.
as to certainty batteries were charged. this was tested on 3 different batteries (all charged) same result.
have tried on 3 starter motors. none are new, but all have worked well recently.
looks like its either re-gap the rings, or add another gasket to the bottom... OR just get a higher torque starter.. (assuming they make them for 4 stroke 50 cc's)
|
|
New Rider
Currently Offline
Posts: 24
Likes: 1
Joined: Oct 22, 2015 11:16:14 GMT -5
|
Post by freespirit on Oct 23, 2015 12:52:39 GMT -5
so.. an update..
got new kick start gears, new starter, and new bendix otw..
hopefully that gets me back putting down the road. i don't know about you guys, but for me, a scooter is my sole transportation.. and i live alone.. so when it breaks.. im SOL. haha..
at least the kickstart gears will arrive sunday.. so i can get it going again then...
|
|
|
|
Post by pistonguy on Oct 23, 2015 15:29:26 GMT -5
Back way up. It Did start on the current system correct? and came to a dead Stop upon cvt or clutch work right? Too much Compression? How Much do you have? This is a Advertised 9:2-1  You buddy with the gas in the engine may be referring to Hydraulicimg the cylinder, with the plug out shed' Blow that Gas out the Hole and or You Crankcase is overfilled with gas. Sorry nada the plug out once would clearer this unlikely issue. |
|
