1972 ct90 Lifan swap

Ordered a clutch cable, a new front brake cable, and a new exhaust yesterday. Will have to take the exhaust to a shop to have custom fit since the original one doesn’t line up.

My handlebars have some play where the quick release has worn the teeth down that lock the bars in place. Think a layer of gasket paper will fix it?

Clutch cable came in through Amazon. There’s no way this thing is going to work. Anyone have a clutch cable they can recommend?

Your engine looks like it's set up the same as a Honda 4 speed. I think you could buy a Honda CT70H cable...or a reproduction. Are you using stock bars?

Universal clutch cables are cheap, but with a little modification, you can get a brake cable to work.

kirrbby said:

Your engine looks like it's set up the same as a Honda 4 speed. I think you could buy a Honda CT70H cable...or a reproduction. Are you using stock bars?

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Yes stock bars. I’ll look into it thanks.

What’s up with the shape of the exhaust port on the Lifan motor? How can I make these parts fit? I went to a muffler shop today and the guy said someone might make a brass fitting to cover the hole and allow the exhaust to be flush.

Tuuubbs said:

What’s up with the shape of the exhaust port on the Lifan motor? How can I make these parts fit? I went to a muffler shop today and the guy said someone might make a brass fitting to cover the hole and allow the exhaust to be flush.

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Does your exhaust fit into the hole? Do you have the two “half” collars that hold it into place?

If the lip of the exhaust fits into the exhaust port, there are collars that sandwich the pipe and fit between the lip and the mounting flange that is loose on the pipe.

WarnerSteel said:

Does your exhaust fit into the hole? Do you have the two “half” collars that hold it into place?

If the lip of the exhaust fits into the exhaust port, there are collars that sandwich the pipe and fit between the lip and the mounting flange that is loose on the pipe.

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It doesn’t fit into the hole, it’s too wide and the bell shape stops where the bolts come out, don’t know about the half collar pieces, exhaust only came with the loose piece on the pipe

You can grind some metal off the lip until it fits in the hole. Make sure you use a fresh crush gasket. If the nuts on the studs bottom out before the exhaust seats on the gasket, you'll need some kind of spacer (like the two half collar pieces). Also be aware, that the muffler probably won't bolt up to the original mounts. You may have to fabricate a piece of bar stock and attach it to the shock mount. You may also have to play with the angle to make the seating on the gasket flush. Remove that ugly rusty heat shield to make it easier to work with. But since you said you ordered a new exhaust, none of this is really necessary.

You need the exhaust spacers...parts #1 in the CT70 fiche. pipe end goes in...then the spacers...then the flange goes onto the studs and presses the pipe end tight into the crush washer and head...making a tight seal.

So the spacers just press the lip of the pipe into the motor when you tighten down the flange?

Tuuubbs said:

So the spacers just press the lip of the pipe into the motor when you tighten down the flange?

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Yes.
You'll need the crush washer in there too.

Well it took me 4 and a half hours of filing, but I got the new stock replica pipe filed small enough to fit the port on the motor. The mechanic at my shop at work gave me a Mill Bastard and said have fun. I didn’t.

I have an extension and crush gasket on the way from eBay, clutch cable should be in tomorrow. Might take her out for a loud spin around the block tomorrow afternoon if it does arrive tomorrow.

After those things all o have left to do is change the tires and connect the engine’s electrics to the bike.

Anyone know if there’s a 2 piece 30mm flange I can replace the original one with, or will I need to have the pipe cut, a new one put on, and the lip welded back on? I can cut the one that’s on the pipe off no problem, I just won’t be able to file it down enough to get the bolts through and have room to tighten nuts.

Also I tried to tape the exhaust spacers to the header pipe to see how it lines up and to make sure the collar can bolt down, it can’t. Will I have to cut them in half to allow the bolts to go further through the collar?

Ended up taking the bike up to a muffler shop who was able to do it after hours. They ended up using 1.25” pipe and cut out the original section of tubing from the curved bit at the head to the muffler. It isn’t pretty but I wrapped it in black heat wrap.

I took it for a spin and found that my clutch wasn’t acting properly. It was pulling to the maximum distance I could pull by hand on the actual clutch, but putting a pipe wrench on it I was able to give it much more swing. I had the cable in the receiver on the clutch incorrectly. Still not able to pull all the way even with the adjustments all the way out, but it functions as it should.

Ordered new tubes, tires, and bands recently and the tires came in today. Took the wheels off the bike and had an incredibly hard time trying to get those old rotted tires off. Ended up cutting the tread off and using a torch to heat up the beads enough to get them over the rim. Minimal rust on the front wheel, some rust on the rear wheel around the stem for the tube and where the wheel had been sitting from not moving in 40ish years. Bearings look good from what I can see, grease is still clear. Ordered new hub dampers as well because these ones are toast.

Waiting for spoke bands to come in so I can get these new tires on. Then I have to start on the electrics. I had been driving it around my neighborhood all week before today. It’s such a fun bike.

That is one nasty looking rim, I've thrown away better looking ones. Get a wire wheel on a drill, and remove as much rust as you can. Then paint it flat black and maybe no one will notice from 20 feet away. Many a time I've had to make spacer sleeves to get rid of clutch cable slack. Once I even used a 1/4 inch drive socket. I've also used electrical tape instead of rubber rim bands.

I sanded down the inside of both rims and lines them with the band as well as tape on the rear wheel. Got the new dampers in and am having an extremely hard time getting the sprocket to fit back on the wheel.

Got screws for the rear section of heat guard for the muffler in this morning. Bent the old front heat guard to fit the shape of the new pipe *enough* lol. Also put the 1,000th mile on the bike and changed the oil after 46 miles on the motor. There was a good bit of metal shavings on the drain plug, but things are running well. How long should I wait before the next oil change?

A lot of old parts vibrate and make a lot of noise, any tips for dampening those sounds? Mainly coming from the tail light/license plate assembly, metal battery frame, and the reflectors on the front forks.

Very important to adjust the valves now. Change the oil again after 100 miles. Hopefully there will be less or no metal shavings. There's no filter, but a screen that you may need to clean. Then every 500 miles. Many of the vibrating parts you mentioned have rubber dampers between the nuts and bolts, which have probably rotted away. Either get new ones, or mount them solidly. Get some kind of cushion for the battery frame (like a piece of foam). Find a way to tighten anything that's loose.