electric start "silver bullet train" engine

[gary55]

Just got BT80 couple of weeks ago.... I can tell you that my pull start was a joke, I think it said in the instruction manual that the pull start must be operated with care! I personally have had no problem with the electric start, Yet! But just wanted to know that the pull start backup option was operational and able to at least start the bike. As suggested in the manual pulled very lightly on the pull start as to engage the pull start system to the engine could feel it bite then pulled firmly just enough to pull the engine over a couple of times it felt awful and grated a couple of pulls later and started to slip when trying to turn engine until it went all together and would only engage if you turned the engine over with the electric powered starting motor!? Kinnda defeats the object but after successfully starting the engine only twice it now pulls out completely without engaging at all. So removed pull start casing and was greeted by little bits of shaved white / cream plastic and noticed that the part that engages with 1 of 4 points on the end of the crankshaft / starter motor gear assembly (1 way / free wheel incorporated in its design) which had very sharp edges had simply shaved successive slices of plastic! yes you heard me right simply little plastic ridges that should normally engage with the sharp edges under force simply shaved of all the plastic that would normally engage pull start to engine was simply shaved away until nothing remained to engage with. meaning the pull start just pulled out to its limit and wound back in again without doing anything! Useless I got mine from petrol scooter.co.uk will be contacting to let them know I mean I know its intended as a secondary or backup starting system but should at least work! otherwise might as well just left it off saved making the BT80 even wider than it should be and could have had a lever or switch to lock the centrifugal clutch so bike could be bump started little rough with out clutch but viable (easier if using a stand that lifts the back wheel free of the ground), could be made so that the lever / switch disengages once the engine is starts up gets up to speed thus allowing the centrifugal clutch to become un locked and function normally again once the bike is started. Will let people know how I get on I am using the 48 teeth sprocket that came supplied with the kit even though the manual states a 44 tooth. Pulls away ok from standing start but tops out at around 30 mph 33 if ya make her scream that's with 29inch 700c wheels / tyres. I have a 48, 44, 36, 32 tooth rear sprockets and can tell you that when I tried with the 36 tooth it struggled but was still running in at that time with running in oil mix & run in restrictions it reached a max of 37.4 mph with slight rear wind and I weigh around 11 stone. A head wind took severe penalty's on this top speed. This was all stock on the same bike and wheels tyres ect my old 66cc china girl (expansion chamber exhaust, HP carb, 1mm skimmed of head slight increase to compression & 32 tooth rear sprocket) hit 47 mph in slightly favorable wind conditions! I got 4500 hard miles with that config before piston wrist pin bearing disintegrated and the 9 HSS rollers destroyed my piston and rings and to lesser extent the cylinder and ports. Was the 40mm stroke and 40mm intake stud spacing & type B high hole piston. Not sure whats inside BT80 only removed pull start cover so far. Also NT type carb that came with kit leaked from float bowl gasket! I switched it out for the speed carb that came with my old china girl. Fixed leak but thin k I may have lost a slight bit of top end power & engine RPM. Don't know if what the jetting is stock for the BT80 carb or the speed carb if anyone can help?

#70 is stock.

 

[Jamie McCaffer]

Put the NT type carb back on and found that it seemed to leaking fuel, A substantial amount! Not from the float bowl gasket as I 1st suspected but it seems to be coming out of the primer buttons hole into the carb body. Stuck a bit of blue tak around the primer button to try and stop leak will let you all know how that goes. Had a little closer look at the difference between NT carb & Speed carb and the 2 main differences seem to be that on the Speed carb the fuel hose intake is fixed in place with very little room between the input nipple & carb body where as the Nt carb that I got with this BT80 kit has a removeable fuel input nipple in way of an 8mm brass screw in connector that sits directly on top of the fuel shut off float needle valve with adequate room to connect the fuel supply hose coming from the Tank or inline fuel filter depending on your config. Also I keep reading tips thatif using an inline stock fuel filter that you should remove the built in fuel filter incorporated into the fuel tap assembly. I have allways ran with both filters & never seem to have any fuel starvation issues or the like. Anybody have any input on this? the other major differences was the jets looked slightly different the NT fuel & air slide & throttle needle where different lengths and one was wider than other so not compatible with each other plus NT had 4 throttle needle valve position settings for rich / lean adjust & Speed had 5 positions. My BT 80 ran a lot better with the NT carb on was smoother, accelerated quicker and reached a higher engine RPM speed than the speed carb did. Also had a quick hour running with the HP carb on but my BT80 didn't seem to like it! At all wouldn't after endless amounts of adjustments even tick over even with the tick over / idle speed screw tightend all the way in as far as it could go even with the spring removed. Only way to stop it dying was to take up tension on the throttle cable so in effect having to keep the bike slightly throttled just to stop it stalling!

 

[Jamie McCaffer]

#70 is stock.

Yer thanks for that am glad to be able to add my input on the BT80. Haven't quite made up my mind on whether I actually like it as much as I thought I would when 1st drooled over BT80's spec's. (Electric start seems over rated, When you factor in the size of the thing, It's overall weight including battery ect it seems a hell of a lot heavier, You need the extra power just to simply lug all the extra weight around!
They are claiming that the power output from this 70cc 2 stroke unit at 6000 RPM is 5HP! Please if any one has had chance to get one of these things on a dyno then please share the results as up to now think that this figure has been inflated a bit would love to see it's stock power vs RPM graph curve compared to a standard stock china girl 66cc. Also BT seems to me to be a bit better on bottom to mid range in comparison but seems to struggle to get up to a high engine RPM.
I would love to see the stats head to head stock on a dyno. One good thing I can say about it is with the engine off & even with the extra weight seems like there is less resistance from turning the disengaged clutch than the manual clutch type these seemed to still scuff on the clutch pads even with clutch pulled in 100%.
Also like the fact that when you come of the throttle on the BT80 clutch disengages and your free wheeling with out the engine braking effects of the manual clutch type. Just Flying along with at a bit of speed with the engine just idling Bam,Bam,Bam,Bam.
This will also stop the free play that develops in the drive train of the manual from forces not just to the back wheel but also from the back wheel (Which is required to pedal/ Bump start the manual clutch version and the transition of clockwise then counter clockwise repeatedly, May causes your Transmission to wear out more quickly!

 

[Jamie McCaffer]

#70 is stock.

Also Don't know if everyone else Who has the stock BT80 handle grip switches / throttle config.
The funny thing is when I 1st looked at it I thought seems straight forward ignition on/off rocker type switch with a push button switch to engage the electric starter motor.
Also noted that they had the fore thought to include a light switch, All very good but my BT80 came with instructions that made what is marked as what looks like the light switch to be actually the ignition on / off switch & the big Red Rocker switch on top which you would have been forgiven for presuming was the engine Kill switch is sat temporally redundant. Presume for future use as a light switch to bring the BT80's on board 12 volt battery and charging system into a very useful feature. I plan to add a 12 volt lighting and turn signal, brake light & horn. So will Try to rewire switches so that the switch marked with what looks like a light on / off symbol, Controls the lights and the big red engine kill button..... Yes you have guessed it...Kill the engine / turn off ignition. Anyone have any suggestions as to why they may have done this...
Apart from them being a bit....Er Yer 1 of them! I
ie… One of the switches is prone to failure or is only able to handle a low amount of electrical current ect.

 

[Guest-650085]

okay, so i have been looking into the silver bullet train engine and after all my looking have found out that the company that creates these engines does not produce parts for them at this time. and i found this out by asking the ebay seller, that is the manufacturer of these engines where to purchase parts, and they straight up told me that they dont make parts, however assured me that no one has ever had problems with them. anyone else know of an engine similar enough that you can use parts from it for this engine?
http://www.ebay.com/itm/Electric-St...ash=item281ded7a74:g:AfAAAOSwyKxXhbDR&vxp=mtr

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[MacArthur-401]

Does anyone know what size the carb is. The carburetor doesn't fit on my bike, so I need to buy and adapter, Idk the size, the guide book doesn't say and the website took off the specs..

 

[MacArthur-401]

hey i feel like i have been ripped off lied to cheated i got one of those piece of sh*t motors i have spent so much money on this piece of crap going tru one of the companys you said and that is birddog and they knew this motor was crap and selling it if i had anyway down or lived any where close to them whoever is in charge there i would punch them right in the mouth and do a lot more for selling this sh*t and not giving there customers the heads up about this piece of sh*t motor kit i have been tru 5 heads and piston sets in two months and road my bike twice and one of those time it broke down i was not racing also i am understanding now why birddog has not responed to any of my emails about the junk they are selling. and im the kind of person that dont like people f***ing with my money so now i am thinking about what can i do about this all i know somebody better come correct about this like they say anything can happen at anytime so you have to be careful because you never know thanks for the heads up and maybe we can do business

Buy from bbr.com

 

[Chainlube]

Does anyone know what size the carb is. The carburetor doesn't fit on my bike, so I need to buy and adapter, Idk the size, the guide book doesn't say and the website took off the specs..

Got a picture, or at least a name of your carb?

 

[MacArthur-401]

Got a picture, or at least a name of your carb?

I found it, it's 30mm. I remembered I bought an upgraded carb manifold, so it said the size on it Only bike berry has it for some reason, I couldn't find it anywhere else.

 

[MacArthur-401]

I found it, it's 30mm. I remembered I bought an upgraded carb manifold, so it said the size on it Only bike berry has it for some reason, I couldn't find it anywhere else.

My bike frame is too small, wouldn't allow the carburetor to fit, it took me a while to find a 30mm offset manifold. Found alot of 32 and 40mm smh but only one 30 mm