RD200B back on the road

[jmendoza]

In 2008 when our governor decided to double the vehicle registration fees in California, I non-oped many of my bikes.   Recently however, my twin sons have reached the legal driving age, so we decided to take the1975 Yamaha  RD200B out of mothballs and put her back on the road.

We drained off all the fluids, carbs were already dry but we cleaned them anyway. New gas, and oil, new battery, re-synced the carbies, new hand made air-filters (used Uni-foam sheet) a little top off on the oil tank with Motul 600(710) lubed the cables, lubed chain, set tire pressures, and then she fired up on the 2nd kick!

The grin on Ben and Buds faces was priceless as they took their 1st ride on a street Yamaha twin.  Both of them commented that they liked the feel of the power-band when it hits, who wouldn't?  Plus the smooth power delivery of a twin is a sensation unto itself, needless to say, they were really stoked. Only issue is the clutch slips a bit until the bike get good and warm, so we ordered new friction plates and new springs.  My boys have been riding dirt bikes since they were 5 years old, but street bikes are a little different animal.

Next project will be to awaken the  1971 CT1-C Enduro. We ordered a new petcock valve seal, battery, and it uses the same clutch plates as the RD200, so because the CT1-C was also slipping before it was put away, it will get a new clutch as well.

Am using 1 pint of water to 3/4 gallon of 92 octane E15 gasoline to remove all the ethanol. A drop of red food dye in the water helps you see it more clearly when decanting. Although a 1/4 tspn of anhydrous (dry) Magnesium Sulfate (Epsom salts) can be added to remove any cloudiness from the decanted gasoline, yuo have to then filter it to remove the salts. I found it much easier to simply let the gas/water mix sit for 24 hours after shaking it  or 5 minutes. When left to sit for a day, the gasoline becomes crystal clear and can then be decanted and used in your bike.  It may sound like a hassle, and it is a little trouble, but not near the trouble you have to go through  dealing with old fuel, clogged jets, and corroded carbs and rotten rubber components in the fuel system.  The bike likes it better too, because depending on how much ethanol is in your fuel (up to 20%) it makes you bike run up to 10%leaner than it should.

[Czakky]

Awesome! Let's see some pics of those bikes!

Doesn't that process knock the octane down though?

[jmendoza]

Maybe 3/4 to 1 point, which is why I use  92 instead of 91 octane.
Running C98 (94 unleaded ethanol fee gasoline) costs $10/gallon, and VP is not always available.
Running C110, C112 is too high of an octane unless you mill the head and jack the compression way up.  110 octane just fouls plugs and wastes fuel in a stock RD/RZ.
One simple way to compenstate for lower octane fuel is to simply go up one jet size as a richer mixture raises the knock point.

However, dropping the fuel by 1 octane point is not significant, but what is significant is that removing the ethanol put the mixture back where it should be. Recall that if the fuel is 10% alcohol, with a fixed jet bike like the RZ, it makes it run 5% lean. That is a much bigger and problematic issue than dropping the octane 1%.

Of course, if you have milled your head 15 to 20 thousandths, or have a Koolhead with combustion chamber inserts that give you 135 to 150 PSI compression, you will have to use bigger jets and run C110 or C112 to avoid detonation and seizures.     

[SoCal250]

Hey Jay, it's been a long time man! I can't believe your twins are that old now.

FYI, our pump gas is 10% max ethanol in Calif.

[Czakky]

 

[rodneya]

Im glad that I can still buy 94 ethanol free gas here

You may want to get some new tires for the old girl and think about new crank seals.

[jmendoza]

Rodney,
the RD200 got a full rebuild. It had 2360 on it when I got it, and at 3200 I did a total overhaul. I bought a second RD200 to get the parts that were missing because back then, they were much harder to find. Engine is on 2nd over (.50mm) new Yamaha pistons, has new seals, rods, bearings, gaskets, sprockets, chain, rebuilt carbs home made epoxy-glass reeds, new tires, new filters, brakes and cables, rebuilt forks overhauled autolube pump, all new oil and fuel lines.  Replaced the tank,rear fender, bars, headlight, taillight lens, couple blinkers, rebuilt dynamo, points and condenser, tach, and new seat pan with a Pit Perspective cover (correct stock reproduction), original tool kit, and now it has just turned 4000 miles.

It would be easier to list what is original as opposed to what all has been rebuilt/replaced, but the engine and frame number match!
Th RD200 was the first bike I purchased that was over 5 years old, and I will never  buy a "project" bike again.  It took far more money and time  to get it correct than if I had just bought one in good running and cosmetic condition.  Age and sitting introduces a whole new set of problems that were never issues back in the day when  they were still new. It used to be crash damage, abuse, and wear related issues that you had to deal with and repair, plus the normal service as outlined in the manual. But the RD200 proved to me that once a bike has sat for years, just walk away....they will need a lot more than you could ever believe!

[Striker1423]

Rodney,
the RD200 got a full rebuild. It had 2360 on it when I got it, and at 3200 I did a total overhaul. I bought a second RD200 to get the parts that were missing because back then, they were much harder to find. Engine is on 2nd over (.50mm) new Yamaha pistons, has new seals, rods, bearings, gaskets, sprockets, chain, rebuilt carbs home made epoxy-glass reeds, new tires, new filters, brakes and cables, rebuilt forks overhauled autolube pump, all new oil and fuel lines.  Replaced the tank,rear fender, bars, headlight, taillight lens, couple blinkers, rebuilt dynamo, points and condenser, tach, and new seat pan with a Pit Perspective cover (correct stock reproduction), original tool kit, and now it has just turned 4000 miles.

It would be easier to list what is original as opposed to what all has been rebuilt/replaced, but the engine and frame number match!
Th RD200 was the first bike I purchased that was over 5 years old, and I will never  buy a "project" bike again.  It took far more money and time  to get it correct than if I had just bought one in good running and cosmetic condition.  Age and sitting introduces a whole new set of problems that were never issues back in the day when  they were still new. It used to be crash damage, abuse, and wear related issues that you had to deal with and repair, plus the normal service as outlined in the manual. But the RD200 proved to me that once a bike has sat for years, just walk away....they will need a lot more than you could ever believe!

Haha, yeah... a lot more for sure. What it needs a crank and top end? Pfft sold! Whoops, it needs everything else too :/