Yamaha Motorcycle refurbishing

Buy a case of beer, take your time, invite Del the Cat over to play.

(Oh yeh, and mixing oil/petrol gas by hand is fine, but I'd prefer to restore it to original)

Del Blink

Del if you need some wind in your face please jump on Virgin and non stop it to Vegas and I'll buy some cold beer and we can go out in my jeep and I'll show you places that bikers can not get to. Check out our site playniceoffroad.com.

It's becoming easier to locate parts for "older" bikes, so go for it!
Just the usual advice: Clean the air filter, change the gearbox oil, clean the carb, lube the cables, check the brakes, clean and lube the chain. If it's been more than a couple of years, the tires (and tubes) are probably shot.

I've done a bit of searching for the correct way to clean a dirty motorcycle chain, and most state that kerosene should be used. Since I don't have any kerosene, I'm wondering if it's okay to soak the chain in parts solvent.

Try mineral spirits, it's the same as stoddards solvent and it's cheap.

Another product that is very close to kerosene is good old diesel fuel. You may be able to get another mortgage on the house and buy a gallon.

Got a buddy at a gas station? Or do you have one of those sinks like the garages have, a sink stand with a pump and nozzle that flushes varsol on your parts? This is the best approach, then air dry, and clean again with varsol if it was really dirty. Place the chain on its side in a flat pan and poor some oil in this flat pan over the chain while your at it to a level just the width of the chain. Allow to soak over night. Then get some PJ1 foam lube in the spray can from any motorcycle shop, and the next day after soaking in oil, lift the chain and allow to drip until not much more oil is dropping from the chain. Then take a rag and wipe away the outer covering of oil, you don't get it all, but it helps to pull away a lot of the oil residue, then heavily spray the foam lubricant onto the chain, and place the chain in a plastic bag, like the bag you get chains with when you purchase a new one. You can spray the chain several times into the plastic bag. The next day, pull the chain out and assemble onto the sprockets and link the ends. Make adjustments to tighten up the slack on the chain.

You may not believe it, but according to the license plate, it's been sitting 19 years on the north side of the house (with gas still in the tank, and the carburetor not drained)! The air cleaner was missing, but I found some vent filters at Home Depot that can be taped on the "screen". Then tires filled up and are holding air, but I only put 20 pounds in them and intend to drive slowly. Surprisingly there are no cracks in the tires, but it only got a little afternoon sun in the summertime where it was located.

If I could find a way to return it to original condition I would try. Get it running any way you can to enjoy it, but aim for original. Reminds me of the early years of electronic distributors. All the old timers experienced mechanics said toss them and get one with points. And toss them alternators.... I don't know Jack about bikes. Is the cable similar to a speedometer cable? Is the oil pump free?

When that bike was new I used to ride with guys that owned them. I ran Kawasaki's.I would buy premium gas and mix Amzoil two stroke oil at the recommended ratios. Be-careful the DT1 could through you for a loop if your not cautious.

The bike will run great with fuel/oil pre mixed in a can.

Mike

If you decide to fix/replace the cable (supply tube from the oil tank?), I'd suggest mixing the oil/gasoline to supply internal oiling, until you are sure the oil pump works. Fill the oil tank, then have fun on the bike, and check the oil tank a few miles later to see if any oil has been pumped into the engine.

Being riding/racing 2 stroke off roads for 23 years, for me theres no better peace of mind than having mixed the oil/fuel ratios myself. Especially if its being cut, ported and on the edge. Restoring to original is always better resale value if you intend to sell. Bit confusing, hope this helps.

That's a backwoods fix to the problem. Don't do it. Replace the cable. Yamaha spent considerable time and money getting that machine into reality and it works fine just as they intended it to.

I was a Yamaha sales and service agent when the DT1 was introduced to the market. It's not the best bike ever presented but it gives a solid performance, and it'll be reliable.

Use good fuel, choose the plugs carefully (preferably use the factory spec ones) and you'll have a good honest old steed.

Cheers,

Stu

Using a little more oil than required will make the engine last longer is something I have found with these types of engines espically the boat.

Careful on "Using more oil" in premix as the mixture is more viscous and will have a more difficult time going through the main jet and actually produce a lean mixture, the opposite of your intentions. With a ultra lean mixture, a two stroke will put a hole in the piston in one hard ride. You may be wondering how I acquired such wisdom. Uhhhhh . . . . I asked my ex-mother-in-law as she knows frickin everything.

I get a kick out of these old bikes. I still have a 1975 Suzuki GT 750 (3 cyl 2 stroke). I agree with Stueywright that the best would be to get the auto injection system working again.

Way back when I raced oil injected Suzuki's, the one I modified to run on pre-mix needed another change to run on pre-mix. That particular Suzuki injected its oil into the intake (naturally) AND some directly into the lower end crank bearings. Therefor if you did not run the pump you had to put a hole from each transfer port to the crank bearings so that some of the pre-mixed gas/oil would go to these bearings. You would have to talk to an old Yamaha racer or mechanic to see if this modification (or something like it) is needed on your engine.

I can tell you a procedure for checking to see if this pump works if you like and also a "backyard" way of eliminating the cable to the pump if you can not fix it (which would be best).

Boy, does that take me back! If I remember correctly, isn't the Dit-1 a 250? I still have a SC-500 motocross bike, which was basically a Yam 360 on steriods. They were all part of the same model line--horrible machines but fun anyway. The 500 had so much power that they had to take a gear out of the transmission so they could make the gears wide enough to stand up. I detuned it for torque and it made one tractor of a bush bike! As a motocrosser, it was the shzts--Yam only made it 2 years.

I, like everyone else at the time, pulled the oil pump 'cause it lightened the machine about an ounce and a half. But the other thing was the oil tank was so small that I had to fill it before the gas tank. I didn't notice a lot of difference either way. The convienience of the oil pump was nice. I'd say its your call to fix or not.

Jon.

First of all, if you're going to refurbish a bike do it right. The Oil injection of Yamaha works and has for years on thousands of machines - go get the proper parts and carry on - also, I think that you'll get sick of mixing and throwing away half-baked fuel soon enough. If it isn't used right away, it doesn't stay stable unless you are using a fuel stablizer - another waste of assets. The money and frustrations of not having the oil injection working, is far worse than the alternative of fixing the injection system, however, this is only my opinion ... I only have been riding and racing since the early 70's, so I'm sort of new at this .......

Thanks for the suggestions. It is unknown whether I can get the cable. With a broken cable I can't test the pump. The pump puts out more oil at higher RPM, and also more oil with the throttle opened more. If I remember right, it is designed for 25 to 1 mix. I remember taking off with full throttle, and seeing the cloud of smoke in my rear view mirror (it may be more than 25 to 1 at full throttle). They started selling oil for 50 to 1 mix after the bike was made. That was what I was planning to use. I would prefer not to offend other people with a cloud of smoke.

The front brake was stuck, but I got it loose with WD-40 (cable rusted). The chain is the least of my worries right now, but great suggestions. Next problem is the carburetor full of "varnish" from evaporating gas. I want to soak in in gas for a while, but can't get the cable off. I have ordered piston rings from ebay. A dealer told me I needed to get a whole piston ($120), because the rings wouldn't fit. I took the $10 gamble. I also need to re-foam and upholster the seat. It was uglier than you can imagine.

S

Hey, StandardsGuy,

I have ordered piston rings from ebay. A dealer told me I needed to get a whole piston ($120), because the rings wouldn't fit.

I'm also attempting to bring life back to 3 1970's bikes... a Honda XL250, a Suzuki 185, and a 400cc Kawasaki, so I have an interest in your project. I'm wondering, if you checked compression before ordering new rings. Thanks. Skeeter

The rings were taken off, and I don't know where they are. At least 1 was broken.

S

We have an 'old style' lawnmower repair shop ( among quite a few others), and do quite a lot of Bowden cable repairs. New inners, new outers, new solder-on brass ends. Maybe you have just such a shop near you? You can buy all of the components of the cable and have someone handy make it up for you, if you don't want to tackle the job.

I once had to temporarily repair a throttle cable by using a cut-open fishing line swivel (brass) and crimped it onto the cable inner with the shot-sinker crimps. A little flux and a dob of solder. That thing has run for 21yrs so far. Temporary? There's nearly always some slack in the outer so that you can draw through the inner, a little, and shorten the outer enough to get some more inner to solder on the little knob. Make sure the inner is not all frayed or you'll not be able to push it back home.

I'm confident that you'll be able to get a cable.

Cheers,

Stu.

I never thought of that. I'd be surprised if there one close. Good suggestions.

S

From the replies I am led to believe the cable is push pull rather than a rotating one. If you can locate a NAPA Power Equipment Products catalog numbered PEP-8, it has thirteen pages of push pull cables from small engine applications. Over 100 applications with pictures and a handy length chart. If not available designed for the Yamaha, you should be able to get one of these to work. Good luck. If you want, I could probobly send pictures from the catalog I have.

It has a steel cable inside a sleeve. I'd call it a pull cable. There is a Y in the middle, with one cable going to the throttle, and one to the oil pump. That one is broke. I haven't been able to get into the Y so far. Only the speedometer and tachometer are rotating ones.

S

No need to get into the Y normally.

5 gets you 10 that its only the end has pulled off. Cables very rarely break in the middle.

Having said that, yours is probably the exception.

Stu.

My experience with oil injection with two strokes is your better of mix the oil and gas separate in a 5 gallon can so your mixture is consistant with the performance of the engine. When you use the bikes oil injection system the you could run into the problem of the mixture of oil injection being to rich which will boog down your bike or being to lean and you could end up ruining your piston. When you do your mix in a 5 gallon can you can obtain through trial end error the best mixture and the run with it for as long as you own the bike.

Ironically I bought the bike because of the convenience of the oil pump, but things have changed. I hadn't though of the oil causing less gas to get through the jet, resulting in a lean mixture. As I recall, I put in a smaller jet because of the altitude here. I wonder where the original is? Maybe with the piston rings?

S

Progress report:

• I got the piston rings in from ebay for $10 (they fit).
• Got breaker points from ebay for $10 and got them in, and have spark!
• Solved air cleaner problem (see previous post).
• Soaked carburetor in old gas from tank along with chain saw gas & oil. Lots of sludge came out, but sleeve still frozen. Got 2 used carbs from ebay for $25. Both have movable sleeves. Will be able to use idle speed adjustment from original with one of them.
• Petcock was plugged. Was able to drill out varnish in normal pipe after soaking in naptha, so it will be usable. May have to drill reserve too, but still soaking (in kerosene now).
• Got off a lot of grease with a chisel and screwdriver and paper towels.

S

SG,

Cookin' with gas.

Congrats.

Cheers,

Stu.

For the latest progress report, see my newer thread "What to use on throttle sleeve to keep it free?"