high idle???

[jmnjrpa]

May have found the problem??? The advance tube was dislocated inside the engine. I also found the exhaust valve clearance on #1 to be at .002"/.08mm --should be .009"/.22mm. Have to check all now -- maybe next weekend

[TopCatGr58]

Well,
Sounds like you might have found your vacuum leak, but yeah, as the engine warms up, those clearances will narrow, possibly even not completely closing a valve, definite aggravation to good tuning!

Facebook doesn't allow direct linking to their photo albums, you need to create an album on Photobucket, or even in your own profile, and then you can link to it!

If you are up to getting some extra $$ from your newly acquired plating system, there are several/many MNS members here that might want to take you up on your "GOLD" plating services for their parts, JAT!?

Keep us posted on your progress!
T.C.

[jmnjrpa]

Thanks TC, will do.

[jmnjrpa]

Trying again[url]http://www.photodump.com/jmnjrpa/d0f37a51ea8adb14.JPG.html[url]

**Editted to a url type link, "dump" changed their policy and don't allow direct linking like they used to, that's why we changed the info the HOW TO thread to "bucket" ! T.C. **

[tarzan]

I have better luck with photobucket.I tried to post a link after I went to that pic manually and couldnt get it to post an actual pic only a link.

[jmnjrpa]

Well, I got back from John and Kat's MOM late Sat and finished the valve job. Sunday morning wrapped it up and cranked her. Yep, yessirre sure fixed the valves- No Backfire thru the carbs or out the pipes. IT EVEN IDLES AT 7000 RPM NOW(that IS 7 thousand) . Spent the rest of the day looking at it and smoking a cigar. Think I have got to kill something! Bike just looks too damn good. Allright carbs get yanked one more time next weekend.

Here's what I have so far;

81 MNS
Type III carbs
Seperate pod filters
MAC 4 to 2 pipes
All valves are set on the tight side

No fuel leakage
The float heights are virtually perfect.
Carb kit (was running 110 mains across)
Have 120 mains in #1 & #4
Have 125 mains in #2 & #3
42.5 pilots (same as what it was running)
Checked all idle screws for bad or missing o-ring and washer
Set all idle screws 1 & 1/2 turns out
Backed off on the main throttle idle screw
Reconnected the vac advance line
Could not run long enough or at low enough rpm to check for vac leaks
Butterflies are preset within .002" of closed (+/-.001)
Diaphrams all appear good
No excess wear on the slides
Boots are triple coated with Plasti-Dip

Appreciate all the help. Anyone got any ideas??

Thanks

[bikerphil]

Sounds like the throttle cable isn't in the slot on the carbs properly, or it's somehow kinked. Check up at the grip adjustment too for free play.

[psycoreefer]

Did you check to make sure the linkage isn't hanging up on the clamp on one of the inside cylinders, you know the ones that hold the carbs to the engine side boots? It may not even seem like its hitting the linkage but try loosening the screws and rotating them around so there is no way they are touching. Don't ask me how I know....

[Ken Talbot]

IT EVEN IDLES AT 7000 RPM NOW(that IS 7 thousand) .

If the carbs have been bread-tie sync'd, with a somewhat fat bread tie, a very high idle is perfectly normal until you crank the idle speed adjustment down. The pre-sync will get all the butterflies set to the same amount of opening, but all will be way more open that what is needed for idle.

If you have adjusted the idle scew down and it is not making any difference, then yes, there must be some problem with cable routing.

[jmnjrpa]

Looks like 3 for 3. That has got to be the area. Thanks guys, that will be the area I am going to concentrate on. I swear I have checked it before but the simple things bite the hardest.

[jmnjrpa]

Thanks to all!!!
I pulled the diaphram so I could see the slide/butterfly. It was open almost 1/8"????? I never did anything to the throttle cable so WTF?? Checked all linkage for interference and even compared it with a spare set. No problems. Anyway I backed off (as far as possible)about 1/4" till they closed. Buttoned it up and she cranked and IDLED right off!

After warmup she still idled until I grabbed the throttle a couple of times then it went to 4500 RPM. I believe this will come down when I finish adjusting and do a sync.

I have one concern. After warmup and run for a min or two I noticed all headers were cherry. The temp here is about 100 degrees. I was getting some very minor hiccups and ever so slight backfires when idling. Could this be an indication of rich or lean mix? It was dusk, otherwise I may not have noticed.

All pipes looked the same so if it is off, then all are equal more or less.

[Crazcnuk]

Lean is the hottest.... not sure if rich would get hot enough to glow...

The only times I saw an exhaust manifold get red hot I had the timing way off (retarded) on a 1967 GMC 3 ton truck with an inline 6, and on an IH 956 farm tractor when the timing idler gear came loose.

[TopCatGr58]

If the headers are getting cherry red/hot, then sounds like it's a bit lean. If you are going to be running it for a while doing the synch, put a fan blowing across the front of the engine to help cooling.

You have Pod filters and aftermarket pipes, have put in fairly large main jets, but still have stock 42.5 pilots at 1.5 turns out. Try turning the pilot screws/idle screws out another 1/2 turn or so, that'll richen it up a bit.

T.C.

[jmnjrpa]

I forgot to mention I was running with the pods off. I bet that might have leaned it out some also. Thanks!

[MindWebs]

yep sounds lean.

it's does sound like a lean condition, turn the pilot screws out a bit more..

Look at it this, spark plugs are CHEAP, frying a motor is expensive!

if you set it rich and back it off with riding till you get it right, your engine will
run cooler.(safer)

Vacuum syncronizing is a MUST for these bikes, i too bench synced my carbs
only to fine that they were way off from correct setting.

Good luck!!

Webs