Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 175 & 200 Talk => Topic started by: Gizo on October 04, 2014, 06:42:39 PM

Title: Motor advice
Post by: Gizo on October 04, 2014, 06:42:39 PM
I have just bought two 175dt bikes plus heaps of spares.
We now have both bikes running,  
One has a bit of noise coming from the bottom end,  it goes away as soon as you increase the revs,
does anyone have any ideas?
Other than that the bikes run and start well,  we still need to adjust the brakes, and check the oil pump.

It seems that no one trusts the oil pumps and pre mix the fuel,  would it do any damage to disconnect the oil pump and just premix fuel?

Hopefully will have the bikes registered in the next few weeks
Title: Re: Motor advice
Post by: Redrust on October 04, 2014, 06:50:12 PM
Have you gone through adjusting the clutch cable. I had a mystery tick that I almost tore the engine apart to find. Premix is safer but if you feel confident with the pump give it a try just might smoke a bit more.
Title: Re: Motor advice
Post by: premiumjo on October 06, 2014, 06:34:45 PM
Just remember, if you remove the oil pump and premix to plug the ports where the oil lines go so you arent sucking air. Keep in mind also if you premix, you are effectively running a leaner mixture.
rd
Title: Re: Motor advice
Post by: disc_valve on October 07, 2014, 06:36:12 AM
Hi,

Your bottom end noise could well be wear on the fibre idler in the Generator drive train. A bad case can sound like a berserk coffee grinder at normal tickover, disappearing at around 2000 rpm. You'll need to pull off the clutch case to see how much backlash there is in the drive train. The noise stems from the generator having six magnetic poles, so the shaft is "notchy" in its rotation as the poles alternately attract and repel each other. At low speeds, this sets up chatter in the drive gears which disapprears at higher speeds as the generator builds up enough inertia to overcome the chattering.

It's almost a characteristic noise on the 175/200 (like clutch chatter on the 350), and is not a sign of any imminent danger until itr gets really bad, but the fibre gear will strip eventually without warning, meaning no sparks and a long walk home (been there, done that!).  If you have a selection of gears, fit the one with the least amount of backlash - or try Richard to see if he has any new ones left.

Graham   
Title: Re: Motor advice
Post by: Gizo on October 10, 2014, 11:38:44 PM
This does sound like a coffee grinder,
This sounds very likely, I will look into it tomorrow
Thanks

Tim
Title: Re: Motor advice
Post by: Gizo on October 12, 2014, 04:06:27 AM
Changed the idler gear,  but for various reasons bike wouldn't start,  the main reason being the battery was flat.  Looks like the generator is another problem,  we think it might be part of the noise issue
Title: Re: Motor advice
Post by: Redrust on October 12, 2014, 03:36:34 PM
Its necessarily your generator. Check your rectifyer bridge first. Then go to the generator.