high rpm miss

[edgo]

I've got new spark plug caps and wires in it. I purchased some used coils off Ebay and put new wires in them. The problem occurs with both the original and the new used coils.

Thumperjsa made a good call. The plug test this morning shows lean conditions on cylinders 2 and 4. I chopped it at 60mph in 5th gear. They are white with a little black soot line. I'll richen out those floats this afternoon with my new caliper and I'll bet that will solve it.

I do have some 142 mains I can try if the float adjustment doesn't do it.

And believe it or not I have a spare TCI too that I can throw in for good measure. I'm the son of an electrican so I've been playing with soldering since I was about three. I'll check your page Randy and do those fixes.

Thanks,

Ed

[edgo]

Nice page Randy. That TCI board looks like basic vintage 1970's electronics. My other hobby is collecting and restoring 1970's audio gear. Are those TO3 transistors available or is a replacement out there? Wouldn't a recapping of that board really help performance? I know what new caps do for sound quality in an amplifier ands caps are only good for 10 to 15 years max, right? Seems like new caps and a resistor check should be in order for everyone.

Ed

[thumperjsa]

Since 2 and 4 are lean, it should not be spark related as far as coils and TCI since 1/4 and 2/3 share common of coils and TCI. Since you replaced the wires and caps, that should not be an issue either. You can still check resistance though to verify all is OK. I think there is a tech tip on this site on how to check that. I would also eliminate petcocks because again, common shared things with the two cylinders being lean.

I would still look at the fuel system since the only thing individual is carbs and intake. New intakes mostly eliminate excess being sucked in past the carbs so fuel does not get delivered into the cylinder. Still could not hurt to spray while the engine is running to make sure it is not an issue.

Remember when you check float height, it is from inside the lip of the carb body and not the lip you are measuring from. If you are only a mm off, it should not be that bad. But having a couple out of sync in height from the others, could be an issue. Speaking of sync, have you synced the carbs?

This link points to another thread about carb float adjustment. Ken has a good picture in it of the place to check adjustment and it also has a good discussion about adjustment. .link

Another couple of thoughts.

Are you sure your floats are floating. If they are leaking, they could be a problem as well. There are tips on the site of how to check the floats.

Also if you have a blockage in the mains or other part of the fuel circuit, it can also cause a lean condition. An extreme way of testing this would be swapping position of carb bodies. But again I say extreme. I don't know if I would go that far.

Good luck.

[edgo]

I have not synced the carbs with any kind of gauge. The bike idles fine and runs well on the bottom end. The pilot circuit seems to be OK. After the carb rebuild and cleaning it was doing the rpm surge thing because I had the butterflies open too far. I had tried the breadtie gauge. I played with that and got it sorted out the best I could by eyeballing it.

I took the floats out when I replaced those valves that let gas into the bowls. None of the floats had gas in them so I don't think they are not leaking. My mains are brand new so they shouldn't be an issue. I cleaned the needles and they look good but I didn't remove the needle jets and clean those. I'll do that too this weekend.

Ed

[randy]

Ed,

Good call on the caps. Whenever I accuire a piece of vintage audio gear, the first thing I do is re-cap it. The trouble with re-capping the TCI is that Hitachi dipped the component side in some rubbery goo that's a bitch to remove. A lot of work.

The TO-3's are available, although not under the orignal part#. the TO-220's are also available. They're just diode protected darlingtons.

NTE has 'em, NTE240 something, if you need it I'll look it up, but those rarely go bad.

thumperjsa, it IS possible to have electrical AND fuel problems at the same time. Don't ask me how i know!

[edgo]

I adjusted the floats on 2 and 4 and I cleaned out the needle jets. The needle jet were full of crud. These two things got another 1k rpms out of it. I doesn't break up at high rpms in first and second gears. Third does it a little and fourth gear gets to 70mph and then it stumbles. I didn't try to get a breakup in fifth since I didn't get out to the interstate. I put the 142 mains in it in the morning and see what happens.

I got this bike from my uncle in July. He bought it new in 79. The first time I visited in about 1989 or so it was in the garage with electrical problems. It sat for years and then about three years ago he got it running. But he then bought a Harley and the bike sat outside for two years and through last years hurricanes. It had a canvas tarp over it. It was a rust bucket when I got it. My uncle past away in August from a long battle with prostate cancer so I have to get it going for him.

Here's a photo, I hope it works.

Ed

[TopCatGr58]

Hey Edgo,

I think it was PGGG who said it, and I should have noticed it too! With both Indy filters and aftermarket pipes, you should probably go up 3 sizes.....to 145's. SO...your 142's will be close, and with a higher fuel level, you may be able to get by with that? In the lower gears, there's not as much resistance so the engine doesn't need as much power/fuel/air to spin it up, but in the higher gears, it takes more power to push it along, and so if it's lean, it makes sense that it would still miss at higher rpm's and higher loads! You'll probably notice an improvement with the larger jets, but whether it will fix it completely in the higher gear is questionable, good luck!
BTW, you do have the vacuum advance hose connected to the #2 carb body, not to the intake port!?
T.C.

PS, my father passing away in 2000 was my inspiration to getting Godzilla back on the road after 9 years....life IS too short!

Pss: The photo link didn't work, feel free to send a copy to me and I'll put it up for you, IF you don't want to get a Photodump or similar account!?

[edgo]

No change with the 142's. I'll get some bigger ones.

Ed

[edgo]

I signed up at photodump.

Ed



Below link is FULL SIZE 1500x1000 image.

www.photodump.com/direct/edgo897/1100.jpg

[GNEPIG]

.. wow Ed, thats 3 of us in florida that have allmost the same bike.
nice ,we should all go for a ride some time

[GNEPIG]

.. here's the other one, this one is in palm beach Fla. Viking500usa is the owner
Specials Rock!!!

[edgo]

In the rides section I posted about meeting during '06 Bike Week. We can meet at my aunts house over there and go for a ride.

Ed

[thumperjsa]

I am down in South Florida with my standard. I went to 05 bike week for the first few days. If I go again, it will be for the last few days. Worst part is getting a place to stay in Daytona.

I stayed about 30 minutes south at the 05 show. Real pain going back and forth. But a lot cheaper. Any deals on places to stay for 06?

[edgo]

My aunt is in New Smyrna Beach, which is the next town south. I can get her to host a bbq if you all want to meet somewhere. She's just off SR44 on the beachside. It's a perfect location. My XS11 belonged to her late brother so she'd love to be visited by a few of his bikes. It would be cool.

Would you guys ride or tow your bikes in? Maybe we could stay a night or two at a local campground.

Ed

[thumperjsa]

Personally, I would ride like I did last year. I haven't any camping equipment though. I don't have enough bagage storage to carry a tent or much else. The 05 Bike week, it was pretty chilly at night.