Tuneup Troubles

[Erik the Red]

Yeah, it was a slipping clutch. When I adjusted it before I didn't leave any free play in the cable, so it must've been just a touch engaged. I re-did it, with about a 1/4" of play at the handle, and she's runnin' good.

Thanks for the all the input and advice on the bike. Except for a few minor issues, she's a-rockin' and a-rollin'! If it weren't for the knowledge on this forum, I'd probably still have my carbs apart on the coffee table in the living room, scratching my head.

Oh yeah, installed Tkat's fork brace last night too. Dang, what a difference! Anyone who doesn't have one yet, get one. www.tkat.com

Now I just have to hope for a few more days of good weather before it's too cold to ride. Bike's naked, and the fingers were blue after a half hour, and that was even with wool glove liners.

[mro]

originally posted by the Viking
Now I just have to hope for a few more days of good weather before it's too cold to ride. Bike's naked, and the fingers were blue after a half hour, and that was even with wool glove liners.

Bummer,
the weather here is one of the last few saving graces to living on the Left Coast. Local airport (where they measure the temps.) 79 today and supposed to be 81 tomorrow.

Did wear a jacket other night for the first time since end of summer tho............
---------------


mro
btw
have you vac synced your carbs????
if not, you will be pleasantly surprised by performance

[Erik the Red]

Yup, I built Nashville Bill's vacuum gauge carb synch tool that's in the Tech Tips. Total cost was about $20, but that's 'cause a buddy is a plumber and I grabbed a scrap chunk of 3" PVC. The vac gauge itself was about 10 bucks.

For anyone else making it, the amount of vacuum was only about 2.5 to 3 mm Hg on my bike. You don't need an industrial gauge; just one that handles 5-10 mm Hg should be fine.

I'll be getting a Colortune pretty soon so I can nail down the perfect spot for the idle/mixture screws. Pilot circuit is a little sluggish compared to mid-high rpm throttle response.

Top speed was only about 105 the other night. WOT, (slight uphill grade). Is this normal for these bikes? I was sort of expecting another 10-15 mph out of her.

[TopCatGr58]

Hey Erik,

What gear and what rpm?? If you were near 8.5K, then you probably still have some clutch slippage you were talking about earlier? I didn't reread this thread, what pipes and intake/filters are you running? What are your main jet sizes?

Aside from the carb tuning, there is also the timing....electrical, have you checked to make sure that's correct?

Going slightly uphill, you would want to be in 4th gear!
T.C.

[Erik the Red]

I was in top gear and I think the rpms were somewhere around 7-7.5k; it just wasn't pulling anymore. I've got the Jardine 4-1 pipes with the stock airbox, and the mains are 137.5's. (pilots 45, air pilots 210) Are 4-1's enough reason alone to go up a main jet size? I did check timing, and it's dead on. (on the F of the timing plate, hooked to #1 plug wire) Vacuum advance checked out too (5200 rpm, 36 degrees). Any thoughts?

[TopCatGr58]

Well,

With Air Pilots of 210 instead of 180, you're already leaning things out a bit, and the 4-1 pipes are probably contributing to that as well. What do your plugs look like?

You could probably go up a couple of sizes, to 142.5's without much worry of being too rich. The larger mains should give you the stronger topend power you're looking for!
T.C.

[skids]

If he is speaking of '78 XS 11 E - "Rhona", then 210 pilot-air jets are stock. The 180's were for 80 and 81 vintage. I would work with the other parameters...

Originally posted by TopCatGr58
Well,
With Air Pilots of 210 instead of 180, you're already leaning things out a bit,

[TopCatGr58]

Hey Skids,

Thanks, looks like we've found ANOTHER Clymer's Manual error, as stated on page 145, table #2, carb specs, lists 180 air jets for all of the early models, 78E, 79F, 79SF!?

I thought I remembered a discussion about the stock air jets before, and that someone had stated 210's as stock, but couldn't remember which model bike!?
T.C.

[skids]

Clymers will get you like that!
The first time that manual gave me trouble was when I did my first valve adjustment. There is a mistake in the example.

[Erik the Red]

I pulled the plugs after my ride this weekend, and all looked decent. They had the light tan color (insulator and electrode both). I have a lot of popping coming from the muffler, but it only seems to be when I'm coasting or when I let off the throttle in a lower gear (i.e. higher rpm range). If I go up to 142.5's, will the idle/mixture screws need some tweaking? Or should I dial in the mixture at the idle rpm?

Top speed this weekend was 103, but this time it was level ground, maybe even a little bit of a downhill. I haven't been up to speed enough to determine if going slower with each run is a trend, or if it's just due to the topography and wind conditions I'm running in. Would it be possible that something is changing inside the more she runs? She sat for 20 years before I got ahold of her.