Kismet?

Not sure whether this is a lucky occurrence or not.  Bike has about 130 miles on it since the rebuild and after taking it for a sedate ride out yesterday, found the new plugs had arrived.  

Stuck a new plug and plug spanner in my back pocket and rode out to a quiet, mile long straight near my home.  As I slowed down, the engine started popping and fighting the brakes.  Stopped and the idle from 1500 rpm previously is now at 3000rpm.  What on earth?
Removed helmet and the bike sounded loud, very loud at the front end.  A 5mm hole had appeared at the bottom of the first bend in the pipe.  More scraping and prying produced a large flake of exhaust putty and revealed a lower bend that looked like lace.
The previous "restorer" had very cleverly filled the pipe with exhaust paste and painted over it.  
No point in trying a plug chop with an exhaust without the correct backpressure, so returned home in a disgruntled frame of mind.
In mind of buying a new Fresco front pipe from the bay, I decided to first look up the correct yamaha part number and stick it in a search...

Search came back with a bike breaker I bought my like new rear damper from.  He specialised in importing vintage jap bikes from road salt free California.  I look at his eBay shop about 3 or 4 times a week, so I know this ad was very recent.
Original Yamaha DT175mx full exhaust in excellent condition.  Correct part number stamped on it.

It was quite expensive, almost twice what I would have paid for the fresco front pipe, so I sent an offer.  I guess eBay let's sellers know if you are a previous customer because he said he would not budge on price, but as a returning customer he would ship it for free.  At least I got £10 knocked off.
His message said the pipe came in a job lot of spare parts that came with a bike he imported.  The bike was fitted with an aftermarket exhaust and must have been replaced very early in the bikes life as the original looked to have had very little use.  Light surface rust only, removed with a scotchbrite pad and a coat of paint added.  No rust pits or holes.  Only a few small dings of the type picked up in storage.

Expensive, but what price for originality?  Was it good luck or bad luck that caused the exhaust to fail just as that ad appeared?








 

I really like the 17 tooth countershaft sprocket I put on my CT1, with a stock 45 tooth rear sprocket. Most of the streets I cruise around town on are 45 to 55 mph speed limit, and the bike cruises well at those speeds without winding it out. In fact the RPM pretty much follows the speed, 5,500 RPM is 55 mph, 6000 RPM is 60 mph. When I go down to Pacific Coast Highway, where people are going upwards of 70-75 mph on the open stretches, I've gotten it up to a 65, but I prefer not going over 60. This ain't no freeway bike, even though it is freeway legal.

Exhaust arrived and looked as it did on the ad, so no problems there. It arrived freshly painted, but not knowing if the paint was heat resistant, I took it to work and subjected it to various cleaning processes. Gave me the opportunity to see what it was like under the paint.

Looked to be in really excellent condition, just had a couple of very small stone dings at the front. Was going to heat the pipe up and take them out, but decided that discretion was the better part of valour and better quit while I am ahead.

Got the pipe painted with extreme heat resistant paint, used a full can of it in about 10 coats to make it as durable as possible; fitted it and just got back from a 50 mile ride to cure and final harden the paint.

No problems to report.

Pics.

Exhaust cleaned up.

 

Exhaust fitted to bike and cured at running temp for over an hour.

 

Condition of old exhaust where the previous owner had welded and filled it before painting it.  The grey bits are where I tried to stop up the holes as a temporary measure.  It was like playing Whack a mole.

 

Gawd.  If it's not one thing it is another.  Noticed a small puddle of transmission oil on the floor under the bike after its been stood over the week.  Probably about 1" diameter.

Further investigation has found two new oil weeps since the new exhaust was fitted and both were joining forces under the shift shaft area.

 It was apparent the shift seal had been weeping slightly and further investigation revealed the tach drive shaft seal had let go, filling up the drive chamber, overflowing past the tach cable, down the front of the cover and airflow carrying it back under the engine until when on the sidestand, it joined forces with the shift seal.

No other leaks apparent..  So with the two smallest seals leaking only, I'm guessing the gearbox is pressurising.  Small seals with less surface area will always leak under pressure first.

When the new genuine seals arrive it looks like I need to remove the oil filler cap and blow down the breather tube to see if it's blocked.

Maybe I disturbed it when I fitted the exhaust somehow.

If it's not blocked I'm at a loss as to why both only started leaking after the new exhaust was fitted.

The trials of the Vintage motorcycle restorer....

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Sorry to hear your new little issues, the bike looks stunning. 

I've found quite a few transmission vent tubes blocked on the monoshock 175's  Not sure why. 

Your bike looks great.
175 MX is a top bike .
Regards
shyted.

Good Lord.  I decided to put the bike on an agreed value policy and to this end I have had the bike professionally appraised by a classic bike valuation specialist...

Had to send him dozens of high resolution, close up picks of every nook and cranny of the bike as well as my provenance documents.

I'm reeling. 

He noted that the various factors of the bike, very low mileage, provenance and condition put the bike firmly into classic investment territory.
He notes that given the right people in the auction room, there could be a lot of interest.  However he feels that his valuation is reasonable in average circumstances.

So valuation he came up with. £6750.. 

I don't think I dare ride it anymore.

 

You've built a stunner that I'm sure any of us would love to have!  That said,  I don't know whether to give my congratulations or condolences?

In any case, I say "ride it"!   

I’d say, if was meant to be parked, it wouldn’t have handlebars… but do avoid the puddles and sand dunes..
Sneezles61