650 Mod's 78 Fighter Build

Steve- never heard of this one before- what does unbolting the coils do?

Leon- i'll definitely have to do this. I've tightened the caps up, but who knows if the thread is actually grabbing anything or missing the wire a bit like you're saying. Worth a check too.

I'll have to do this in 9 days- i'm off to the mine for a longer shift this week.

Thanks boys!

Devin

Taking the coil;s off the frame should give you more slack on the wires to test.
Steve

Oh ok, got ya. I thought you were leaning towards it causing some sort of a leak down with the resistance end of things. But this makes sense

Devin

So after spinning about 250km on the new plugs, i've decided that the B7ES plugs are too hot for me. After plug checking every once in a while to see how things are looking, I'm going to play it safe and bump back to the B8ES. Reason being is that the electrode is burning pure white with no colour on it at all, and the ground strap is real light beige, almost white. I've noticed the pipes are bluing up more now, so she's definitely running hot.

I've read over a few articles that disect plug reading pretty well, and feel i'm almost in the danger zone. Here's one of those articles: www.4secondsflat.com/Spark_plug_reading.html

On a side note- did a compression check the other day to make sure all is well- running 140psi across the board. Still having that rich issue on cyl ##2. I'll check carb boots next time I have it apart.

Devin

650mod wrote: So after spinning about 250km on the new plugs, i've decided that the B7ES plugs are too hot for me. After plug checking every once in a while to see how things are looking, I'm going to play it safe and bump back to the B8ES. Reason being is that the electrode is burning pure white with no colour on it at all, and the ground strap is real light beige, almost white. I've noticed the pipes are bluing up more now, so she's definitely running hot.

I've read over a few articles that disect plug reading pretty well, and feel i'm almost in the danger zone. Here's one of those articles: www.4secondsflat.com/Spark_plug_reading.html

On a side note- did a compression check the other day to make sure all is well- running 140psi across the board. Still having that rich issue on cyl ##2. I'll check carb boots next time I have it apart.

Devin

Have you checked it with it running? Spray the boots with starter or carb cleaner. a sudden jump in RPM will be a leaky boot.

Hey Jon!

I haven't done that yet. I've just read that leaky boots could cause a rich issue (which I thought would cause a lean issue). I can for sure do this before I get the carbs off. I just really want to get that cylinder sorted out...

Devin

Update on the carb boots- after a solid 20 minute ride, I gave the good old carb cleaner sprayed around the carb boots a shot. I made sure I sprayed enough on the boot until it started to drip, and coated both sides of the boots. And.... No change in engine speed. That means that this possible issue is scratched off the list.

I took the spark lead ends off cyl #1 and 2 and swapped them. Checked the wires while I was at it. #2 looks like the wire is starting to get pushed around, so I'll have to shorten it a bit. I then ran out of time/daylight to get a decent ride in with the caps swapped, and had to get to bed because I had to be up for 5 am to get to work... 6 days to go until I can chip away at this again.

Thanks for all the tips guys, I appreciate it.

Devin

So now that I've been back working at one of the mines up here, I've had time to think about the bike a little bit. And my thinking time has boiled down to one more potential cause for the one cylinder burning slightly rich no matter how much I tune the carb up.

Here's what I'm thinking (and I'm sure it's been suggested before). If the intake valve on cylinder 2 is set to tight (stays open too long), and lets a little bit more fuel in than the other cylinders get on it's intake stroke, could this lead to/cause my symptom? Like I said, I'm sure someone down the road has suggested checking valve clearances (which I have to in a matter of a month or so as winter is quickly approaching here).

Winter plans for the bike include doing a full seal kit on the upper and lower end, shaft seals, clutch sight glass seals... Everything. That being said, does anyone have a suggested full kit they would suggest?

Thanks!

Devin

Alright ladies and gents, since it's officially winter here with some snow on the ground, the riding season is over. That being said, I NEED to do a full gasket kit on the 650 this winter. Where do you prefer to get your gaskets from? Is there a better brand? When I rebuilt the engine last time, I did a full upper gasket kit- from the base of the cylinders up. The brand was Athena- and they lasted 3 years before tanking on me... So anything better that I have to spend some good money on would be more than ok with me.

Another thing- I saw someone on here a little while ago that did a full rebuild and put all new hardware on the engine. If I remember right, the hardware was all allen key stainless bolts.

And one last thing- I'll also need tires come spring time, so what are some suggestions? The last set I had were Pirelli Diablos that were more of a track tire- super grippy compound but too soft for the road. They lasted maybe 2.5 seasons.

Any tips or suggestions here are more than appreciated

Devin

My C2's engine could use new seals and gaskets, so will be curious to see what's available.

I've bought engine bolt kits off ebay, but it has been some years.
I think Z1Enterprises and others carry them.

As far as tires, I have used Bridgestone BT45 last two sets.
Last two seasons approx. 15,000~20,000 kms./9300~12400 miles.
Work well enough.
I don't push the bike in the corners, and avoid rain.

Hey Rob! How did this season treat you?

I think on a post I follow someone had just bought a full kit that had everything in it. And with the allen head bolts, it looked unreal. I'll have to look into those. That was the tire life you got off one set? I ride fairly hard all around, so I'll need something that can hold up to that. I have maybe 3/4 inch chicken strips left on the tire edges, so I tend to lay it down whenever I can. As for rain- I also try to avoid it and will only ride in the rain if I get stuck in it. If I can avoid it, I won't risk anything.

Devin

I had an OK season.
Always wish I had more saddle time.
Can't complain, as the weather was good this year.

Yes, 15,000~20,000 kms for one set of tires.
Rear will have developed a flat spot by then, and the front, although still having a lot of tread, will be severely cupped.