Progress update....or not.....

[fossie]

In response to Smallkat ...the airfilter number quoted is for GS 500 and is missing the trumpet , (which we supply ) The correct filter is 13780 45D00.
No if the brakes are not as sharp as you'd thought. Push the piston back , lock them with a piece of wood so the don't move then operate the lever it should be a good feel , keep it pulled and see if the lever gets spongier...if so the seal groves are worn and fluid seeps past.
Release the wood a touch and watch all 4 Pistons on a caliper move together at the same rate , it only takes 1 to be slower and the brakes are gash ....I finally tried to retro fit 650 brakes to mine!

[johnD]

Thanks all for the good words. I'm lucky in that this one is only 10,000 Kms old and has been well dry stored. I suppose I will start hitting the known faults sometime, but right now, its as mint as one of these can be. The brakes are rather good, well up on the brake tester and good feel and stopping power on the road. Let's see what a few more miles do!
Not sure why its flat spotting, I'm in the awkward process of getting carbs out at the moment, time for my double strength glasses and a close inspection of all airways, will report later.
Having spent a year or more sourcing OE silencers for the Honda (CB350K2), I'm not keen on the idea of these pipes slowly rotting from the inside. It could be that its so heavily baffled that all condensates are trapped inside, it certainly whispers rather than roars! I'm considering demounting them and giving the internals a good coating of high temp paint or similar..... I am a worrier....
Suffice to say, I'm actually quite taken by the thing. Took the Aprilia out on Sunday, I'm still aching! All that power, and weight, and fuel costs, and sheer physical input. I hardly went much over 70mph. I looked at all the brand new rocket ships at the brekkie stop and wondered..... Why? Bragging rights and pose value I suppose. Bet the Kat gets more attention!
Cheers.

[pookie]

I've got a Kawasaki Kr-1 and a Suzuki gsr750 but the bike I always choose to ride is the 250 Kat it's so much fun and as you said big cc's and power don't matter when you're doing 50mph and over 10,000rpm don't tell everyone though, bike looks great btw

[pookie]

Smallkat, here are some more pics

[johnD]

Think I've found the reason for the flat spot. Main jet reads 58, should be 80?
Cheers

[fossie]

The main jet is 85...are you sure that the 58 is not 85 read the wrong way round ....rejetting down so far from 85 to 58 with standard zorst I'd find it hard to believe it would run well ( barring flat spot.)

[johnD]

As usual, you are right fossie. I was reading it round from the R, rather than from the outer edge. Trust it to be a number that can be read both ways round! Some more investigations to be undertaken.
Air filter is clean, looks new.
Symptoms are:
Runs fine at low speeds, low throttle opening, but just give that hollow, burrrrr noise when larger throttle openings are given. The wall is dead on 5000 rpm. It can be tickled higher, but does not really want to run. Its the transition between pilot and main jets. All jets are clean, carb body has beeen ultrasonically cleaned, nitron gaskets fitted. All rubbers in place and clamped tight. Not an igniter limiter, it will clear the clock in neutral.
Getting too good at whipping carbs in and out...
Cheers

[fossie]

Now I had this problem when I was dispatching my 400, interesting ...either pootling along or screaming along .....eventually found that the slides which are flat sided at the intake had worn through in the grooves so taking air in and making then heavier until full vacuum when they shot up.
Turns out a common issue on the carbs of this period ....mine had done 100,000 by this point but had been found in low milage examples where the carbs had stuck and freed.

[johnD]

If ever an engine needed fuel injection..... or is that sacrilige?
You can see where the cost accountants had the final say, plastic sliders, tin choke lever, one piece plastic fuel valve 'thing'. Mind you, 100,000 up on yours does speak well for longevity, especially for a lunatic dispatcher.
Back for a road test tomorrow, see if my cleaning and blowing has done any good.
So near, so near!
Cheers.

[Smallkat]

In response to Smallkat ...the airfilter number quoted is for GS 500 and is missing the trumpet , (which we supply ) The correct filter is 13780 45D00.
No if the brakes are not as sharp as you'd thought. Push the piston back , lock them with a piece of wood so the don't move then operate the lever it should be a good feel , keep it pulled and see if the lever gets spongier...if so the seal groves are worn and fluid seeps past.
Release the wood a touch and watch all 4 Pistons on a caliper move together at the same rate , it only takes 1 to be slower and the brakes are gash ....I finally tried to retro fit 650 brakes to mine!

I'll give it a go next time I have a few hours spare and I want to feel frustrated. Or, leave as is on the assumption that if the grooves are worn, I can't get replacement calipers anyway!