Bridgestone Motorcycle Parts Discussion Board

General Category => Members: Introduce yourself => Topic started by: Crazygreg on November 16, 2009, 04:00:23 AM

Title: low miles BS 175DT new owner :)
Post by: Crazygreg on November 16, 2009, 04:00:23 AM
Hi all!

I'm Greg, i'm french but curently live in San Francisco, and my friend just gifted me with a Dual Twin 175 in really good cosmetic shape!
THe bike seat for more than 10 year in a garage, covered with a blanket!
The bike have been repainted in white, but it look really good, 6700 miles which I believe are original as the motor is really clean, tires seems original as well, chrome are exelent, except on the muffler where they have some pitting.
I bought new rubber cap for air filter \ carb, now it's just missing the toolbox cover...which I believe seems hard to find!
Just two mechanical problem on this bike :
- AFter re doing the timming, cleaning the carbs, exchanging the spark plugs, I just changed the ignition coils as it was running on one cylinder (right one only, left sometime), it didn't solve my problem, changed the condensers : still the same, right head is hot, left is just warm... there is spark on both spark plug, but seems that the left one sometime stop..
- Right cylinder is running, but smoke like crazy, oil is acutly driping from the pipe joint...setting on the pump cable is good, so look like the oil pump is completly overfeeding ... (might be the left cylinder hoose that is clog or something...)

If someone have an idea? thanks!
(http://farm3.static.flickr.com/2616/4108124531_d02866dc04_b.jpg)
(http://farm3.static.flickr.com/2746/4108876490_1ed47e235f_b.jpg)
Title: Re: low miles BS 175DT new owner :)
Post by: OldSwartout on November 16, 2009, 09:51:22 AM
Make certain the carburetors are clean internally, including the idle jet, are tight on the spigots, fuel level is correct, and that the throttle slides are moving correctly. 

If you are having spark problems it is most likely the points. Sand or file the contacts if you haven't already. After many years the surfaces will have oxidized. I have also seen old points that look pretty good, but had rust on the pivot shaft and didn't close correctly all the time.  I have also seen rust where the contact point is mounted in the base and where the other contact is mounted in the movable arm that caused a high resistance, reducing the spark. You should consistently have 3/8" spark with a good battery.  Bend the side electrode straight out on an old plug as a quick test.  The spark should jump to the side of the plug with ease.

The most likely problem with oil is that the right side crankshaft seal (center of the rotary valve cover) is leaking, causing it to suck air and transmission oil into the crankcase. 
Title: Re: low miles BS 175DT new owner :)
Post by: Crazygreg on November 17, 2009, 12:35:14 AM
THank you so much Oldswartout, will check the seal this week, i removed the right exhaust...and it was full of oil! grrrr
Regarding the spark, i was thinking about making a spark tester so i can mesure precisely the gap jumping, but I will check the other points you mentioned!

Aparently my friend always  run with this bike on one cylinder, didn't realize it...and with the smoky exhaust as well as as the thickness of the black crust in the pipe seems pretty old, head was clean though.

thanks again!
 ;)
Title: Re: low miles BS 175DT new owner :)
Post by: OldSwartout on November 17, 2009, 09:48:12 AM
Many auto parts stores sell a little ignition tester that is a small plastic c-frame with an adjustable screw.  It looks like a small C-clamp with an ignition lead and an alligator clip.  - usually just a few $$.
Title: Re: low miles BS 175DT new owner :)
Post by: Crazygreg on November 17, 2009, 06:29:24 PM
Do you know the dimension of the oil seal?
in the service manual, it just writter "28mm oil seal"
is there any place where I can find the correct filter?
thanks!

 ;)
Title: Re: low miles BS 175DT new owner :)
Post by: old smokey on November 17, 2009, 11:00:22 PM
looks like a bike that would be fun to have running. I don't have lots of exposure with the 175s, but I'd try swapping the plugs left and right to see if it's still the same side that runs (just to eliminate the esay repair option first). It could be electrical, but I think I'd try verifying it's getting good fuel flow thru the carb. Is the 175 carb similar to a 350 where you could take the bottom of the bowl off, let it sit back in place and turn the fuel on for a few seconds? Good luck with it. Post more if you have more or different symptoms as you try things on it.
Title: Re: low miles BS 175DT new owner :)
Post by: OldSwartout on November 18, 2009, 03:37:27 PM
The seal is 28mm ID x 47mm OD x 15mm W.  It is also a double sealing lip (not a sealing lip and a deflector lip).  It has to seal crankcase pressure one direction and transmission oil the other direction.
Title: Re: low miles BS 175DT new owner :)
Post by: rwgibbon on December 29, 2009, 04:26:03 PM
It may be the seal behind the rotary assembly.
(behind the carburetor)

Title: Re: low miles BS 175DT new owner :)
Post by: hankgood on March 26, 2019, 12:36:28 PM
Reviving this post with a couple of question about the left side oil seal (09090-109) discussed above.

OldSwartout provided the size (28mm ID x 47mm OD x 15mm W). I can't find a new, modern seal in these dimensions. I can find the 28 x 47, but all I can locate are seals 7mm or 10mm wide.

• Would these work in this application? Maybe stack two of the 7mm versions - or a single 10mm.

• Also does anyone have the dimensions of the right side 20mm seal (09090-113).

• Should you trust NOS seals in these application - if they are available?

Thanks
Title: Re: low miles BS 175DT new owner :)
Post by: BRT-GTR on March 26, 2019, 01:32:44 PM
           NOS seals seem to hold up OK providing they've been stored properly and are not hardened.

        Modern double lipped seals with two springs ( not a spring and rubber lip, type 23) are almost impossible to find. Couldn't find any for the 350. I like the idea of stacking two 7mm seals back to back, that should do the job, better still if you can get them in Viton. They resist heat better
        Can't help with the 20mm seal size, sure one of our members will have it.
Title: Re: low miles BS 175DT new owner :)
Post by: CL-100 on April 28, 2019, 12:05:48 PM
As I'm new to anything 175, I hesitate to post this but I'm confused by the verbiage in some recent, as well as older posts.

In the Mar. 26, 2019 post by hankgood, there is a reference to the "left" side oil seal (09090-109).  Is this not the right side oil seal in the rotary valve cover?

Further on there is reference to that 28 oil seal as being 28 x 47 x 15mm in size.  I haven't split the cases on my recently acquired 175 yet but I did pull the right side rotary valve cover off.  The  seal on that cover is 28 x 47 x 8mm.  It appears to be a double lip seal with springs on both sides, which would make sense...keeping crankcase pressure in and transmission oil out. 

There is also a 28 oil seal part number 09090-116 (for bikes after 16B) for the crankshaft, on the same parts page.  Could this be the 15mm wide seal referenced in that same post?  15mm seems like a wide seal, but I don't know. 

Also, the question was asked about the dimensions for the right side 20 oil seal, 09090-113.  I'm assuming this is actually on the left side on the left rotary cover.  When I pull more of my engine apart, I'll post those dimensions. 

I hope this clears up some questions and doesn't create confusion.  Thanks for everyone's help.
Title: Re: low miles BS 175DT new owner :)
Post by: OldSwartout on April 28, 2019, 08:28:19 PM
09090-109 is actually the right side double-lipped seal in the rotary valve cover, 09090-113 is the left side 20mm seal as you suspected.

09090-110 and 09090-116 are seals for the center of the crankshaft, before and after 16B.
Title: Re: low miles BS 175DT new owner :)
Post by: Jeff Bar on April 29, 2019, 06:02:23 AM
You should check with Richard for BS parts. Jeff BAr
Title: Re: low miles BS 175DT new owner :)
Post by: hankgood on May 03, 2019, 04:35:18 PM
Quote
09090-109 is actually the right side double-lipped seal in the rotary valve cover

YES - CORRECT - I apologize for incorrectly stating that it was on the Left Side - clearly a senior moment on my part - the whole thread was about the Right Side Seal leaking transmission oil into the combustion chamber.

Anyone researching this problem - the discussion follows here:

https://bridgestonemotorcycleparts.com/index.php?topic=4979.0 (https://bridgestonemotorcycleparts.com/index.php?topic=4979.0)