650 Mod's 78 Fighter Build

glad the bike held up sir.
nothing like the sense of satisfaction you get from building something then riding it all over with no problems :evil: !

leon

So very true, Leon! Especially when you give it a good twist and she wakes right up to 100mph like nothing

So it's been a while since I posted anything here. I moved away for school about a month and a half ago, about 400 miles from home. This weekend I was able to get home for a few days, so I swapped out my fuel petcock vacuum rubber that was leaking. Drained the tank, swapped things out, and put it back in.
At first, the shut off valve didn't shut all the way. So I took the petcock apart, and stretched the spring just a hair to put more pressure on the petcock shutoff. This worked, so the tank went back on, filled it up, and fired the bike up.
She runs MUCH smoother now, and isn't wet rich on the cylinder that supplies vacuum to the petcock. Problem solved- it was DEFINITELY the fuel petcock shut off valve (The flat rubber sheet with the aluminum centre core with the rubber o-ring on one end.
Fired the bike up, let it warm up a little, and roughly dialed in the pilot screw. It pulls much harder, much smoother, and doesn't stutter off the bottom anymore.
When I'm home next, I'll get the ColorTune out and balance the pilot circuit once more, and I'll also balance the vacuum on each carb once more to do a double check.
Overall, I'm really happy that I finally got that issue sorted out. Now I don't have to worry about fuel washing that cylinder, the bike will pull harder, and I'll also gain some fuel economy back

Thanks to everyone who chimed in on this issue- your input is MUCH appreciated. Without forums like this, I know alot of us would just be chasing our tails and taking shots in the dark. For that, thank you so much!

Devin

In the spring I'm going to have to take the engine out and do a complete gasket change out on the bike. Letting the motor sit fr a few years out of the bike with limited oil in it dried the gaskets and lots are seeping now.

As I'm doing this, I'd like to put new piston rings in just to freshen it up (might as well, I'll be into it already), but my question is this- as I'm running a Wiseco big bore kit, does anyone know if Wiseco will sell just ring kits? Or would a simple hone be enough to refresh things? The rebuilt engine has maybe 3,000 km's on it.

Thanks

I got rings for about $12 a set. Might as well do the valve guide seals too.
Steve

+1 on what Steve said. I always buy 1 extra set of rings just in case I get a little over zealous and break an oil ring. Hone, rings and Viton valve seals is always a good idea. Like you said, your already in there. If you need gaskets and stuff search SWEST's " good guys" post for folks we have used for parts and service.

Steve- Do I just get in contact with Wiseco and let them know what I need? Valve guide seals were done when I rebuilt the engine in the first place- so they've got only 3,000 km or so on them, maybe not even that. Is it still worth doing then? Yeah, I figured I might as well freshen her up as much as I can

The old seal set was Athena brand I think. Honestly, it's low quality stuff... my lower cylinder seal started leaking not even 500km in. Thanks for the tips, guys. I appreciate it

I would put in Viton seals while you have it apart. In my the good guys thread are suppliers for gaskets and for Wiseco pistons. They may have rings. Wiseco charges more if you deal with them direct. Worth asking though. Closed mouths don't get fed.
Steve

Sounds good to me! I'll hit ya up when I have her apart if I need anything. Thanks again!

Devin

So it's been a while since I posted up here last, and I've started tinkering on the bike to get her tuned up for when it finally warms up here. We're still dealing with some snow on the ground, and overnight lows of -15 celsius, so I can't really bust the bike out quite yet. There's way too much sand on the roads from the snow plows, so I still need to wait another 3 weeks or so before really getting out for a ride. We had some warmer weather 2 weeks ago where all the snow we had melted, and I was able to fire the bike up and go for a spin.
I did get the fuel petcock diaphragm changed out last fall, and that sorted out the rich issue on cylinder 2. I just have to wait for it to warm up a bit before doing a good pilot circuit tune and vacuum balancing again.
In the mean time, when it's been warm enough, I've started to get the little windbreaker mounted up that I bought a few years ago. And of course, with anything "universal" comes alot of tinker time and modifications to make things work right. I started off by shortening the headlight ears up by around an inch and a half. Re-drilled mounting holes for the light, then started to figure out the windscreen mounts. I had to cut some steel off, bend the bracket in a few spots, but I think I've just about go things sorted out for the time being. Here's a few pictures of the screen roughly mounted up, I just have to add some rear mounting plate support bolts to keep it from bending back in the wind on the road. I think it adds to the overall look of the bike and completes the street fighter look I was aiming for. Plus, it will hopefully add a little bit of a wind break to the ride












Devin

Nice work Devin !

Keep it up :woohoo:

Arnold wrote: Nice work Devin !

Keep it up :woohoo:

Thanks Arnold! Just a few small things to tinker at before I think she's done for now.