Bridgestone Motorcycle Parts Discussion Board
Bridgestone Tech Talk => 175 & 200 Talk => Topic started by: jjwithers on March 11, 2017, 11:53:00 PM
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Now that my 175HS is back together, I am troubleshooting some issues.
The left pipe has quite a bit of black oil coming from the end of the muffler.
The engine was rebuilt but I didn't have 100% confidence in the builder.
The rings should be OK but why all the oil?
Oddly, that plug looks OK and the other side looks black/oily.
-Josh
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Josh,
Excess oil can be a problem when setting up a two stroke, especially on first start up. The high pipes don't help as the oil tends to run back toward the engine. There may be a lot of oil in the crankcases from the rebuild and it tends to build up if you've had the engine ticking over while the engine speed and mixture is adjusted.
Ideally she needs a run to clear the pipes, you then have a short window to make adjustments before she loads up again. From what you say the left cylinder is probably firing nicely, it's the right cylinder that may need adjustment.
Ah the joy of setting up two stroke twins ::). Too much oil is better than too little at this stage, check the oil pump adjustment and stroke setting if all else fails.
Brian, ( also trying to set up a GTO with similar issues but can't take it for a run until she is UK registered. Now have lots of crop circles on big lawn !!)
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Thanks Brian.
How do I check the pump adjustment? Could it be sending too much oil to one side?
And what is the stroke setting?
Also, I forgot to mention that I have added oil to the gas too (as per the manual, it states to do that for the first few hundred miles or so).
The bike runs great, purrs nicely. But also leaks oil like crazy too... I need spend some time with her and find the source of the leaks. But maybe it has to do with the pump? The pump is brand new (old stock) but I could throw the old one in for test purposes.
I'm busy restoring old BMW's (which I know really well) so I need to set time aside and put on my thinking cap when working on this Bridgestone.
-Josh
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Hi Josh,
If she ' runs great and purrs nicely' there's not much wrong with your rebuild---- good job. If you are also running premix with the oil pump ( which you are supposed to do) then there will be a lot of oil going through the engine cylinders - it's messy but fine. Just ease off the premix ratio as she runs in. Remember a 2 stroke has to burn all the oil going in to the cylinders, it's a total loss system, that's where all the black oil sludge in the silencers comes from.
Pump adjustment refers to setting the pump cable adjuster to match the oil delivery rate to the throttle opening, see pages 51/52 of the Clymer service manual on this site for details. Sounds more complicated than it is !
The pumps stroke is factory set and should not need altering, I'm not even sure the 175 pump has this facility, anyone?. In theory. the pump can't deliver more oil to one side than the other but you may want to confirm that the check valve (built into pump outlet connector) on the oily side, is clean and seating properly. (t's only a spring and ball) These stop the engine sucking oil from the pump outlet tubes. Again details in the manual.
Sort the other oil leaks out and she will be fine.
Brian.
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Thanks Brian. Encouraging words.
Aside from a 78 vespa I used to have, I don't know much about 2 strokes.
I need a Bridgestone day to sort through this.
I'll read through the manual again.
What about the right side plug that is oily? Should I be worried about that? On a 4 stroke, it could be bad...
-Josh
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It will probably take 25-50 miles to get the crankcase, bearings, etc. washed out of all the extra oil and the pipes hot enough to burn out accumulated oil. As long as there aren't signs that it doesn't have enough oil, don't be concerned until you've taken it for a decent ride. It took a ride of more than 25 miles to get mine cleaned out after a rebuild.
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It took a ride of more than 25 miles to get mine cleaned out after a rebuild.
I'm afraid to go that far from home! :)
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This is an opportunity for your significant other to participate. A follower in a car is the best safety net when doing the "initials" on these old dudes.
;D
...bert
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This is an opportunity for your significant other to participate. A follower in a car is the best safety net when doing the "initials" on these old dudes.
;D
...bert
If I made my wife follow me around Los Angeles traffic in a car while I zip around on this Bridgestone, she probably wouldn't be my wife for much longer...
:o
I'll figure it out though. It is a good excuse to visit friends with garages and pickup trucks... just in case I need to leave the bike and go back and rescue it.
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Josh
There are check valves at the point where the lines attach to the oil pump. As memory serves, they had an early and late version of these. One can be disassembled, one cannot. If your rebuilder fouled one of the little check valves, oil can continue to enter the crankcase on one side only after the bike is shut down, leading to an excessive oily condition on start up. Since your problem is one side only, either there was a huge excess on tat side from the rebuild,and it hasn't purged, oryou're continuing to feed it from the pump. I agree with all others here that a good long ride will help tell the story. If anyone else has more acurate info on the check valves, feel free to weigh in.
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Old BS Guy........... ( aren't we all ? ;D) Good point about the oil continuing to flow through the 175 pump when the engine is switched off, if the check valve is not doing it's job properly. I'd forgotten that one :(.
Josh, Here's a link to someone who had a similar over oiling problem which gives useful information to help you understand what may be going on.
http://bridgestonemotorcycleparts.com/index.php?topic=4364.0 (http://bridgestonemotorcycleparts.com/index.php?topic=4364.0)
See also the link to Graham Weeks article on a 175/200 pump strip down. I'm not suggesting you strip the pump but he explains the variations in the check valves on the 175. If a good run and omitting the premix does not clear the problem have a look at the offending check valve.
Brian.
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Thanks Brian. Graham's article on pump set up is the definitive guide, without question.
Josh; I noticed in a recent post that you installed a NOS pump. I'm assuming that you hooked up the old existing fittings to it, which is where these check valves exist. If the bike had been inactive for any length of time, the other possibility is that the litle check ball has developed gummy residue around it from sitting with stagnant oil around it. Sometimes just pulling the lines and fitings off the pump, and spraying a little cleaner in them will solve the problem. Be sure you get good oil supply back through them before riding. This procedure will also give you the opportunity to make sure no parts were accidentally omitted during reassembly, like the check ball itself, (if they happened to be the early version which can come apart). Updating to the newer style is always a good idea. My 200 RS had a similar problem from sitting for too long.
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Well gang. I kinda made an big mistake. I took her out for a 15 mile break-in ride to my destination. She made the ride, over the hills, A-OK.
I got to my destination, gave her a good rest. A few hours later, I attempted to bring her home.
I got half way home and the engine lost lots of power. It felt like something was restricting it from the higher RPM. I was thinking fuel as I was riding it. I also started to wonder if it was the oily plug causing a foul.
It felt like that for about a half a mile ( i was not really in a safe place to stop) and then the bike totally died. I coasted into a gas station, tried to kick it and realized it has zero compression.
I have not had time to look into it. I was planning on putting the original oil pump back on.
I'm thinking a seal is bad somewhere in which it caused all the leaking and now, compression loss... and... time for another engine rebuild. ouch.
If somebody in Southern California can rebuild the engine and sort this out, I'll haul it over.
I have a feeling the guy who built my engine really had no clue what he was doing with this particular engine.
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Sad. Sorry to hear. I'm sure the autopsy will show the reason. Keep us posted. It'll be interesting to hear. Obviously sounds like seizure.
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The pistons were detonated.
I had to tear it down to the crank. The crank is out. It checks out.
Now it is time to rebuild, again.
I wish finding parts was easier. I'm so bummed that I have to go through this all over again...
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Parts are easy to get, call the provider of this site. R Clark
Sam Keys
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Parts are easy to get, call the provider of this site. R Clark
Sam Keys
Not all of them. From what I've heard, 175 rings have reached the "unobtainium" category! :(
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Added by Richard Clark 6/14/17
Rings are getting scarce, but I still have them, am working on reproduction Piston and Rings
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Unfortunately your right on there Moonpup. Not everything is as easy as sending an email.
What parts are you in need of JJ??
Dan
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I think JJ wanted rings, seals and a generator
May be get a used generator off ebay and match rings up with something else, seals can be matched up at a bearing store.
Sam Keys
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Yes, i am in need of:
1 wrist pin,
1 set of rings for one piston
1 set of cylinder base gaskets
1 oil pump 'gear case gasket'
If anybody has these to sell, please advise.
The functionality of my generator is undecided at the moment so I'm not sure if I need one. It was rebuilt but I was not getting a charge to the battery when the bike was running. I did use a 3 Phase diode bridge rectifier found on eBay that was marked SQL 100A/1000V - which was recommended on this forum.