what did you wrench on today??

[Buffalo Bill]

Finally got a little project running today. It'd fired previously but was very reluctant to run. Achingly lean.
It's half an FZR250 - relinered to take GSXR400 pistons which makes it 152cc. For a local class which mainly runs singles.
The carbs are 28mm Keihins off a Honda NSR250 MC18. And have proven fiendishly difficult to set up for a small fourstroke - but they were cheap...
Price up downdraft FCR's if you wonder why I persevered, LOL.
The key was to block the powerjet air bleeds. Not needed here but providing way too much air to the emulsion tubes

There's a bigger inlet cam in it. The crank is cut just past the camchain sprocket and the unwanted oil passages blocked off.
Might do 18,000 rpm, we'll soon see, LOL. Doesn't owe me much at all.

Brilliant!
Brings a few questions: When searching for pistons to use in unusual race engines, do you have to have assorted pistons on hand, so you can measure their fit?

[dorkburger]

Wow! Quite an interesting job.

[GregT]

Brilliant!
Brings a few questions: When searching for pistons to use in unusual race engines, do you have to have assorted pistons on hand, so you can measure their fit?

Initially search by bore size needed. I've got a couple of service data books which have bore and stroke dimensions - and some guessing followed by internet checking. Then elimination by gudgeon pin size. Suzuki pin circlip part nos have the pin size as the last two digits so it's possible to work backwards to the pin dia. The early GSXR400 pistons came from a local wrecker with rings in very good condition. They're about 4mm taller than the FZR ones which worked with the 4mm plate under the barrel sealing the unused side. The valve cutaways had to be moved closer together which I did by hand with a die grinder.

[Buffalo Bill]

Initially search by bore size needed. I've got a couple of service data books which have bore and stroke dimensions - and some guessing followed by internet checking. Then elimination by gudgeon pin size. Suzuki pin circlip part nos have the pin size as the last two digits so it's possible to work backwards to the pin dia. The early GSXR400 pistons came from a local wrecker with rings in very good condition. They're about 4mm taller than the FZR ones which worked with the 4mm plate under the barrel sealing the unused side. The valve cutaways had to be moved closer together which I did by hand with a die grinder.

Thanks, I've been considering a vintage race bike and wondered what to do if it needed new pistons.
I thought this kind of a search might turn up alternative options, and yeah experience would help.

[ddaniels]

Fired up the Fizzy yesterday and balanced the carbs. Starts on choke (starter circuit) now like it should but I can't get it to rev very high at all on the choke. With the "choke" lever fully on it's only revving up around 2-2.5K rpm. Weird. I guess I should just quit complaining about it.

[Grimly]

Came out of the supermarket on Friday and was greeted by a small pool of oil under the GS. That damned valve cover gasket leaking - again.
That's been about 1000 miles since the rebuild and it was leaky from one side about 300 miles ago, but I sorted that.
Took the valve cover off, which of course meant the fairing bracket wouldn't allow it to come out to the side, so off with the fairing and its bracket, total pain in the bahookie. Still, once started, easy done.
That's the valve cover gasket that was in the NE engine set. On examination it's gone a bit hard and shiny, but I couldn't see any damage or indentations where the leaks were coming from - nor on the metal faces.
Cleaned everything up and fit a new one tomorrow - I have a couple of so-called Vesrah ones, but they arrived in plain packaging, so I'm not sure what they are. There's another one I bought a couple of years ago, which came from the same source as the previous known-good one at the same time, so I might fit that instead. I don't recall if that was OEM or not, but I do recall buying quite a few spares from the London Suzuki Centre at the time, so it might be one of the good ones.
Hey-ho; just occurred to me it might be a good time to fit the front springs, too. May as well, with the fairing off.

[Burque73]

I feel your frustration, Grimly.

After and wash and wax, I discovered a base gasket leak. Ugh, shoulda left it dirty. It didn't leak before the wash. Maybe I can rub some dirt back in and stop the leak, LOL.

[alke46]

Nothing bike related but my project today was to repair a fractured natural gas line for the heater in the garage. Now I can work on a bike in comfort.

[Hayabuser]

Finally got around to fixing the oil leak on my Katana today... it had only been sitting on my workbench waiting for me to get to it since September.

Generator cover is dry as a bone now, only needed to adjust the gasket so part of it wasn't folded inside of the housing. Four months for that?!? It took me less than 1/2 an hour to fix! Man I suck...

Anyway, it's alive!

https://www.youtube.com/watch?v=YH98ui1n9Yw

[GregT]

The little FZR has an oil leak from the cam cover too...I knew it had a leak but hadn't managed to track it down until I saw a drip yesterday.
Front right corner of the cam cover - the unmodified end. Room's so tight that it'll be easier to drop the engine to have a look.
Not sure why it's leaking there. It's a rubber insert in a channel so it really shouldn't. If I find there's a drainage problem I think I can
add an external drain without too much trouble.
Got the tacho working. It blips to 10 grand on the stand smoothly. Won't idle below about 3 grand. Not surprising given there's next to no crank weight, a big inlet cam and big carbs.
Fuel pump to sort before a test ride. And a customer bike to sort first...

[Grimly]

After cleaning off the residual oil from the top and front, I was happy to see no new oil joining it.
Then got on with fitting the coil relay mod I've been meaning to do for years.
Relay 1 is for the aux lighting, relay 2 is the coil / ignitor feed.
I'm happy that it now starts with the slightest stroke of the button.


[IMG]
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But I think I might need to fit a longer Single Point Ground bolt soon.

[wyly]

IMG_1540.jpg
I spent considerable time wrestling with it but I got my new RS36s in. Also have new computer so I haven't figured out how to flip the picture as yet.

[wyly]

IMG_1545.JPGMy old kill/start/throttle needed to be changed out to a push pull throttle, I drove down to my local ebay supplier and found a 6 wire Yamaha kill/start that had to be converted to the 3 wire GS system. I'm no electrical whiz so it took a couple of hours but I finally got it figured out.

[wyly]

When I was picking up my new kill/start switch I noticed they had '84 GS1150ef up on the table. A complete restoration, everything was broken down to the last bolt, sand blasted, powder coated, polished, clear coated. Nothing has been left untouched. I don't think they ever looked this good new. I'll go back next week to check the progress.

IMG_1542.jpg

[Gorminrider]

Tire_DeBeader-2_20200122.jpg

Funky *@%^$*@%^$*@%^$*@%^$e, but it works great.