Taiyo Juki Bobcat repair

[jirushi]

Hi,

Last Sunday was a good day: I picked up two parcels containing many airgun related goodies from the USA.

These two Taiyo Juki Bobcats needed to be resealed. Normally I would send the valves to Lawrie aka "The King of Seals", but these turned out to be very easy.
The stems screw into the brass head, which is great. Terry Robb's QB78 valve seals fit like a glove, and seal well. Then I used Crosman 160 seals from Ped's kit. The probe o-rings came from my collection of old o-rings. I have only tested the .177, a big bang and three shots at 194, 195, 194 m/s; about 640 ft/s > 7.7 ft/lbs (8.44 gr JSB's). Must do a full shot string, it might be very steep. The tube holds 2 powerlets, of which only one is pierced; the tube cap does not have a piercer. The second is probably meant as a spare, for hunting situations? Japan only made airguns for competitions and hunting.
Very little is known about Taiyo Juki. They made a few models, of which the Bobcat, 380, Junior and Grand Slam are the most common. I think they were sold in the USA, New Zealand and Japan. There is also a Deluxe, which has a magazine. All work on CO2; I don't know why they didn't make pumpers, as those were very popular around that time (the seventies). I have read that Taiyo Juki's were made by the well-known firearms manufacturer Miroku. Miroku did not answer my email for more info (I didn't expect a reply, but ya never know!).

There is some info on the net. A BB Pelletier report
https://www.pyramydair.com/blog/2009/09/taiyo-juki/

Great info on the Grant the Kiwis forum (New Zealand). Grant has two boxed Bobcats. Also info on Danny's forum of course.
https://www.tapatalk.com/groups/gran...isairgunforum/

A great Junior repair report (Another Airgun Blog, such a great website)
http://anotherairgunblog.blogspot.co...h?q=taiyo+juki

A Baker Airguns ad
https://www.bakerairguns.com/product...-pellet-rifle/

These reseals were nice and easy. Now I need to do some testing.
The .22 (top) was very kindly given to me by a member on here from Virginia.
The .177 I found on Gunbroker, and a friend and fellow Titan fan in the USA helped me to get it. It was cheap. The action has a paint finish. I think it is not original. In fact many parts on this example are not original (open sights, screws, trigger spring). But that don't matter.



It is a Crosman 160 clone (yes, I wear awful slippers when tinkering):



This one had miles of trigger creep. I glued some leather on the trigger to reduce sears engagement. Much better now


These old seals become like a sort of tar


Valve stem disassembly. The valve return spring at the top left is not original. It should be longer. I fitted a few washers to make it work better.


Thank you "The Robber" (not everyone likes him lol!)


This German Haweka sight has great glass. The loading of the .177 pellets is a bit awkward with this low mount though.


Any fellow Taiyo Juki owners on here?
Cheers, Louis

[lightning22]

I’ve never heard of this Louis, trigger unit aside it looks very much like a QB from what I can see. I assume better quality components?

[Geezer]

Uitstekend!

[Mark D]

Nice write up Louis

That looks so like a Cr 160 when taken down - I guess suing companies for patent infringements was a lot harder back then.

Was the Cr160 design ever patented ?

[45flint]

Nice write up Louis

That looks so like a Cr 160 when taken down - I guess suing companies for patent infringements was a lot harder back then.

Was the Cr160 design ever patented ?

20 year patent over in 1975?

[jirushi]

Merry Christmas.

@lightning22, yes the quality of the Taiyo's is good, but I have a feeling that the power curve will be very steep. There is a big column of CO2 exiting the barrel after the pellet has left, which can't be a good sign, economy-wise. I think I will need to increase the valve return spring strength. And do more testing.

A few differences with Crosman 160/QB78: on the Bobcat, the hammer is cocked by pulling the bolt backwards instead of pushing it forwards.
The Bobcat has a safety, but it isn't automatic like on my 2nd series 160 (I prefer non-automatic; it is annoying to press the trigger and realise you've forgotten to take the safety off!). And in the Bobcat the second CO2 capsule isn't pierced (I must check if a Crosman 160/180/400 tube cap fits).

@Mark, thanks. I think that repairing airguns, especially when the process is straight forward, is my favourite part of the hobby.
@ 45flint, you are probably right. Rudy Merz's designs must be the most copied CO2 airgun designs ever?
The Taiyo Juki Junior is a copy of the 180 by the way.

Crosman 160 2nd series (I think the white o-ring should be on the tube cap btw, and the black one on the valve body, oops):


Possibly the 380 is even closer to the Crosman 160 and QB78:


Junior (source: http://anotherairgunblog.blogspot.co...mbly-part.html)