Need help, input, information and a hug on running issues!

[clashpistol]

Hi again,

Clashpistol here
1979 SF

The saga continues..... I have seen others with similar issues that have that have given up and sold out. I will win this war of attrition even if it dictates rebuilding my extra engine or replacing altogether!
I am looking for concise answers and trying to avoid wasting more time making more mistakes and throwing more money at. ALL fluids have been changed and moly paste on disassembled shaft. New intake manifolds(probably over $1800 with specialty tools, paint and oils, lubes, cleaners, tank sealer, multiple gallons of beer and countless hours with the initial purchase of $1000 for this and a parts bike) at and not rectifying issues. I have spent a great deal researching here and sometimes misinformed.
The bike upon purchase ran okay but didn't go over 80sputtered and had poor MPG. The bottom of air box was off and it overflowed gas occasionally.
I am still having low power. Sputtering, black plugs and poor MPG. I did EVERYTHING to bike except engine work. I have good compression. Adjusted valves, timing and adjusted chain. I have new plugs, consistent spark and has been synched at every carb filter swap. The bike was completely rewired new fuse box, all accessible electrical components disassembled and cleaned, dielectric grease on all connections and bugs worked out of harness.
I went with Mikes XS pods and exhaust is wrapped. ( much information that re jetting is in order but others say it is not entirely critical) I have properly cleaned the two sets of carb tried swapping and tried airbox in and out with both carbs a few times. I have meticously set floats and checked on numerous occasions. I did not do level check ( adapting drain plugs, leveling carbs and observing clear tubing levels) but did always do at 45 degrees off float anti vibe pin at 25.7 mm. I do not have a long snap ring pliers yet to check and adjust needle position to try to adjust. All jets are stock spec. The emulsion tubes are in proper positions. I am using premium fuel with no ethanol.The only thing dummy did not do last time was check id of orfices to verify stock spec and not drilled out as I finally should have addressed in retrospective as an oversight. I feel bike is running rich but sounds feels lean, but I m no expert as first 4 cylinder large displacement machine. I tried everything else and finally went out yesterday and beat it, winding it out at shift changes at 4 to 5 grand. Upon returning home after a few minutes I had consistant exhaust temps averging +- (10%) 400 degrees F. Pulled plugs. Somewhat black but tips for 1st time were silverish. The bike idles wonderful and not under load sounds good twisting throttle through range but smokes a little at high rpm. I did go from 16 to 17" rims as I had cleaned and painted and and installed new bearings on the 17" thinking it was even swap. On the center stand the wheels turn freely in neutral with no hanging up.
Without educated advice I am considering purchasing all new jets and getting additional 1 size up mains. If you believe this may be the answer where is the best vendor for mikuni jets??

1st gear issue:
Was fine at purchase. The Gentleman (term used loosely. Obviously not an XS member. Turned out to be a total DICK) He gave me bad Ju Ju whe he remarked when I had it completed and took for him to tune (which he blew me off) "Hows your 1st and 2nd gear"? Less that 2 weeks 1st gear slipping and grinding. Got Talbots(?) info on dremel fix flipped bike concisely did as per instructions. It was great for a few weeks and now almost as bad and starting in 2nd gear mostly again to not excerbate till I address again. I just noticed in posts about moving some washer in aftermath.
Well that's what I got. Any info or direction will be greatfull appreciated.

All the best,

Jeff

[JeffH]

Hi again,


The bike upon purchase ran okay but didn't go over 80sputtered and had poor MPG. The bottom of air box was off and it overflowed gas occasionally.
I am still having low power. Sputtering, black plugs and poor MPG. I did EVERYTHING to bike except engine work. I have good compression. Adjusted valves, timing and adjusted chain. I have new plugs, consistent spark and has been synched at every carb filter swap. The bike was completely rewired new fuse box, all accessible electrical components disassembled and cleaned, dielectric grease on all connections and bugs worked out of harness.
I went with Mikes XS pods and exhaust is wrapped. ( much information that re jetting is in order but others say it is not entirely critical) I have properly cleaned the two sets of carb tried swapping and tried airbox in and out with both carbs a few times. I have meticously set floats and checked on numerous occasions. I did not do level check ( adapting drain plugs, leveling carbs and observing clear tubing levels) but did always do at 45 degrees off float anti vibe pin at 25.7 mm. I do not have a long snap ring pliers yet to check and adjust needle position to try to adjust. All jets are stock spec. The emulsion tubes are in proper positions. I am using premium fuel with no ethanol.The only thing dummy did not do last time was check id of orfices to verify stock spec and not drilled out as I finally should have addressed in retrospective as an oversight. I feel bike is running rich but sounds feels lean, but I m no expert as first 4 cylinder large displacement machine. I tried everything else and finally went out yesterday and beat it, winding it out at shift changes at 4 to 5 grand. Upon returning home after a few minutes I had consistant exhaust temps averging +- (10%) 400 degrees F. Pulled plugs. Somewhat black but tips for 1st time were silverish. The bike idles wonderful and not under load sounds good twisting throttle through range but smokes a little at high rpm. I did go from 16 to 17" rims as I had cleaned and painted and and installed new bearings on the 17" thinking it was even swap. On the center stand the wheels turn freely in neutral with no hanging up.
Without educated advice I am considering purchasing all new jets and getting additional 1 size up mains. If you believe this may be the answer where is the best vendor for mikuni jets??


Jeff

Sorry to hear you are having a struggle getting your machine to cooperate.

I got my Genuine Mikuni's from:
http://www.jetsrus.com/

http://www.jetsrus.com/a_jets_by_car...0-96_pilot.htm

So you said it idles good. Do you start it with Choke or not?
Have you tried the Throttle Chop shutdown from cruising speed then checked the plugs??

It seems you are saying all 4 cylinders are responding ok, no popping etc.

As many of the guru's state: I'd get OEM Genuine Mikuni Jets go from there. I assume the Needle & Seats are new?? since you mentioned 'overflowed gas occasionally'.

Let's see what others suggest from your symptoms, but jetsrus has Original Mikuni jets and their service was good.

Jeff

[IanDMacDonald]

I guess I am a little confused. Why are you on the "get a bigger jet" band wagon? These bikes run fine with stock jets. I've ran tons of mods on these Mikuni carbs BS34/MKII's, and hardly had to change much more than needle clip position. What are your mods to justify jet size increase? Custom pipes, (you said pods), anything else?

Take your bowls off and check sizes of jets then report back to the forum.

[TopCatGr58]

Hey Clash/Jeff,

I thought we had some images from the FSM regarding the float height setting, but I couldn't find any in the tips! So....I clipped the one from the FSM for the early model carbs, and am posting it here now.



Hey Ian,

His original post was a bit long, so you might have missed it, but after a longer run he noticed some shiny silver on his plugs...signs of too lean starting to burn his pistons or comb. chamber!

His mods are the XS style Pod filters, he stated wrapped exhaust, but not whether they were OEM and just rusted, or aftermarket. Also didn't specify if he has baffles or any kind of mufflers on as well. The black sooty plugs are a strong indicator of incorrect pilots like the K&L brand. Yes, we need to know what jets he has, just stated that he had cleaned them, and there was 2 banks/sets, original and from spare engine, but again no telling what a PO may have put in there.

T.C.

[IanDMacDonald]

I guess my question is what is your mixture screw settings at currently (how many turnd out)?

[clashpistol]

Thanks for input suggestions and advice

Hi guys,

I haven't had air box flooding since problem occurred after bike purchase. It has not reoccoured (gave up on spelling) since cleaning/rebuild and numerous in and outs float verification etc. So floats are good. As for jetting I was going to and did buy all stock for the carbs and on the way. As for upsizing main/pilot. Decided not to as info was found here and bike ran ok when I first got it and bottom of air box was off sucking larger volume of air I figured so I thought it shouldn t be that big of deal and didn t want to reduce my MPG on the pig! As for plugs of I didn't take pics but went out after sooty plugs post sync rechecked carbs and ran it harder than I have and sooty plug tips we bluish and looked almost like new plugs.
To T.C's float setting tips. Every time I set height I did from gasket surface to round top center. I had boiled floats to verify non-leakage and made sure they were not twisted. So without tube level verification I believe they are relatively precise utilizing a Snap on pocket rule.

So I will post an update when I get new jetting completed.

Thanks again,

Jeff

[clashpistol]

Hi Ian

Mixture screws at 1-1/4 ish.

Thanks

[clashpistol]

Jets have stock numbers on them

T.C.

I don t know if they were altered but replacing.

Jeff

[clashpistol]

Geez read the replys and respond all at once

Headers are stock. I think mufflers are OEM slip on?

Jeff

[TADracer]

Every time I set height I did from gasket surface to round top center.

Did you check float height from the gasket surface on the carb body or from the surface of the gasket? Should be set from the carb surface without the gasket in place....and yes, try to get as close to the setting as possible. Make a gauge from heavy cardboard if you need to. Even a mm will make a difference between lean and rich.

Still, from what you are saying it sounds like suspect K&L jets.

[IanDMacDonald]

Clean your plugs and increase your mixture screws a quarter turn, re-sync, and see what they look like.

[TopCatGr58]

Headers are stock. I think mufflers are OEM slip on?

Jeff

Jeff,

The Stock mufflers were multilayered, I don't think there were any OEM slip-ons, just aftermarket, and they will not have the same level of backpressure as the convoluted OEM mufflers!

BTW, it's a common mistake, but it's just Recurrence.....no "O"!
Another common faux paux is "Irregardless"....no such word, just regardless.

T.C.

[IanDMacDonald]

TC- I saw you have a new movie coming out at the Redbox

http://www.redbox.com/movies/top-cat

[Rasputin]

Jeff,

The Stock mufflers were multilayered, I don't think there were any OEM slip-ons, just aftermarket, and they will not have the same level of backpressure as the convoluted OEM mufflers!
T.C.

I have to disagree with you one this one. Yamaha did make a set of slip ons and they were marked differently. They have a badge attached that states they meet the requirements of the bikes exhaust. I have a set here and I will try to take a pic of the badging that is there when I get enough time.

[rdmcguy]

carb tuning

Jeff,
Sorry to hear you're losing patience,
I know all about it..I have been battling with some of my own.
I don't know what carbs you have but mine had the plugs over the pilots,
And a few here were kind enough to advise me that they need to remain capped with my particular carbs (2h7 series) which cured MY issues,
Also it was suggested to me to make sure my vacuum advance was working correctly..
As for long needle nose....I got a pair of hemostats at harbor freight,
That work great to get to those snap rings in the slides.
Hope that helps....
Joe