Project The Yamaha R4 (Glacially Slow Project)

I will make an airbox for them so no need to worry about the restricted fittings. Now I want to find a suitable generic paper air filter element. Maybe this one might do. Toyota 17801-0Y040

 

I think that Toyota one will be fine and they are cheap, even genuine. Comes from car that produces 100hp so has to flow enough air for my purposes. I can 3D print the parts and lay CF over them or something similar. If I design the airbox so that it is 3 layer construction, the middle layer can be made different heights to change volume. Then I might be able to put it on a dyno to test that.

 

Look here's another set. This from what must have been a pristine 3TJ6. This guy just buys really good, classic models and wrecks them. https://www.jauce.com/auction/l563243381

Trouble is, how do you get them out of the country.

 

Could just throw them away and fit velocity stacks. No, that would be naughty and very loud. I am thinking about this at the moment. Maybe two options:

1. Design a rubber velocity stack like FCR blue ones but have a double lip on the outside to seal into the airbox base.
2. Make the airbox base to fit onto the carb mouths and screw the velocity stacks inside the airbox.

Carbs will arrive early next week so i can choose which way to go.

 

The OEM airbox rubbers from the 3TJ1 are at least 100mm so I want to keep as much length as possible. Don't want to pay the stupid money that people want for their bits either.

 

Once I open the roll of Nylon I also want to use it to print four other parts before it absorbs too much water and I have to fart about drying the stuff (hint, hint).

 

Speaking of bargains.
https://thai.webike.net/en/sd/1355313
134952 THB = 6579 AUD

The seller owns a shop in Bangkok and he brings in container loads of bits and bobs from Japan. Apparently someone wanted to fit these to something and it was beyond them or some such.

 

Notice how the JB kit has a long intake runner that I assume fits into the standard 3TJ rubbers. The 3TJ6 has normal length custom rubbers and has the extension on the air cleaner side (the part with the restrictor). Thus my velocity stack/air cleaner box thingies will need to be quite long or on the end of adapters.

 

FCR's arrived. They are 33mm and from a 3TJ6 or 3TJ7. Took a bowl off and a bit fuzzy but not horrible.
All of the o-rings and hoses will need to be replaced.

 

Back to the Engine:
When I removed my baffle plate, one of the screws was hell to get out. Going through the usual motions I hit it with the trusty butane torch until something smelt like burning rubber. Oops, on the other side was a bonded rubber gasket. Made a new one out of some sheet Viton and used the same low head cap screws that I mentioned before. With Loctite of course. Now you might be thinking, 'why not use some NBR'? Well that would be fine except I don't trust anyone to sell me the good stuff on an eBay purchase.

I am doing a few mods to the gearbox and after that cases should be going together.

 

Been making a press, which is now close to being finished. Waiting for some hose barbs to arrive. I need them because I am inverting the jack. Then I can finish the gearbox stuff and put the cases together. I also picked up a Fizzer gearbox so I will make some seal rings and keep some bearings for them in stock.