My 1327 build

[platinum2]

just wondering what do your plug look like? tan dark or white?

 

[gearhead13]

The plugs have good color.
I ran the bike on the highway for some ways and there is a vibration at 4k rpms which is right at legal speed in 5th. Seems to be a resonant frequency that I can hear as well as feel. Like the bike will vibrate it self apart I think it was there with the 75mm pistons but much worse now.
I am going to do a carb sync, maybe that will help.
The 152.5 main jets are on the rich side I think, it stutters wide open ~6k rpm.

 

[Guest]

Please check both Dyna-S coils full advance with a degree wheel.

 

[platinum2]

is it possible your crank is bent? or bad mains, all it takes is a lil and it will vibrate like crazy, it sounds out of balance
i dont know why shes over heating though, it will get to a certain degree and cool even if its setting still, it is air cooled designed,and will run a lil hotter from thinner cyl walls, but there made to run all day long, if you use thick oil it will run hotter i believe, can you put a bigger oil cooler on it?/synthetic oil?

 

[gearhead13]

is it possible your crank is bent? or bad mains, all it takes is a lil and it will vibrate like crazy, it sounds out of balance
i dont know why shes over heating though, it will get to a certain degree and cool even if its setting still, it is air cooled designed,and will run a lil hotter from thinner cyl walls, but there made to run all day long, if you use thick oil it will run hotter i believe, can you put a bigger oil cooler on it?/synthetic oil?

Some of my starting problems were solved after fixing a flaky charging system, Went for a long ride today and it always started up fine.
Bill, I set the timing with a timing light, after static timing with a 12v tester on the coils, havent had any pinging that I can hear.
The crank is in question because the PO took apart a couple throws and rewelded it. Or maybe my clutch basket is coming apart
I might be getting a stock '83 crank. Is there somewhere in the northwest to send a crank to have it inspected and welded, maybe trued?

 

[gearhead13]

Did a TON of work on the bike yesterday, pulled the clutch out and inspected it all fine, pulled all the plugs and checked for crank twist and bad rod bearings, all is fine. Cam chain tensioner was loose, retorqued the head, the outer two were down 15 lb/ft, set them all to 50, redid the valve lash, most were tight. Changed out the 152.5 mains for 145's.
Fired her up and ran it for a bit and she vibrates, probably need a carb sync. But even at idle I could hear the vibration noise, so I looked around at it and the license plate is making the extra noise, a couple of zip ties and no more noise
I dont know why but I always think the worse scenerio. Anyway I have a crankshaft and starter clutch arriving on Tuesday. Might send them out next winter for rebuild and straght cut gears if I can afford it.
Went for a ride today and WOW, I think the 145's are pretty close, I whacked it open at 100 km/h in 5th and the next time I looked down I was doing 180, weaving in and out of the cager spodes and the occasional Hardly

 

[7981GS]

So comforting to find that a little annoyance was making the strange/evil sound.
Once you get it fine tuned, it will be dangerous!

PERFECT!!! :twistedevil:


Eric

 

[Guest]

Be careful with those 145s
Too much time and energy to mess it up now.
License plate huh? LOL :lol:

 

[gearhead13]

Be careful with those 145s
Too much time and energy to mess it up now.
License plate huh? LOL :lol:

I am going to rehook up my DB A/F gauge and check the jetting. Easier and more accurate than plug chops.
Ya.... it was the license plate amplifying the vibration, but there is still noise at 4k rpm coming from other things. Just the heavier slugs I guess.

 

[gearhead13]

Went for a ride today after wiring up my air/fuel gauge and saw 11-1 at idle and nothing over that at cruise, when I crack the throttle it stumbles and thats when the a/f drops below 10-1 . I have 47.5 pilots in there and I think 150 or 160 pilot air jets, so I am thinking of going to #45's and a set of 125 pilot air jets. Maybe I will just try tuning the idle mixture screw leaner first. Still need to take it on the highway and test the needle and main, but I think the needle is a bit rich. Getting about 32 mpg on mostly highway

 

[Guest]

Went for a ride today after wiring up my air/fuel gauge and saw 11-1 at idle and nothing over that at cruise, when I crack the throttle it stumbles and thats when the a/f drops below 10-1 . I have 47.5 pilots in there and I think 150 or 160 pilot air jets, so I am thinking of going to #45's and a set of 125 pilot air jets. Maybe I will just try tuning the idle mixture screw leaner first. Still need to take it on the highway and test the needle and main, but I think the needle is a bit rich. Getting about 32 mpg on mostly highway

Try the 125 pilot air jets with the 47.5 pilot jets. I could not get my bike to idle with anything else but the stock pilot air jet.
How's the main jet look?

 

[gearhead13]

Try the 125 pilot air jets with the 47.5 pilot jets. I could not get my bike to idle with anything else but the stock pilot air jet.
How's the main jet look?

The smaller pilot air jets (125) will make the 47.5's richer, I need to go leaner.
I found the set of pilot air jets that came with the dynojet kit, supposed to be bigger than the stock ones (~160), might try them

 

[gearhead13]

I finally got time to hook up the laptop, go for a ride and get some data.
She is rich on the top end, A/F dips to 9.x under full throttle, so I am plenty rich. I only wound it out to 7.5 k rpm, it runs out of breath, needs bigger carbs, valves, cams etc. Or maybe its just too rich
If the slides dont fully open until 7-9 k rpm them maybe I was running on the needle still? But with the extra cc's I would expect them to open sooner.
I could post the data file somehow if someone is interested.
A/F Average 12, max 17, min 9 . 16 minute run time
I am going to start by leaning the needle out one notch.

 

[gearhead13]

Here is a screenie of the logworks dat file. At 7:50 I am going from a start 1,2,3 A/F dipping to just over 10-1 and climbing as I back off the throttle.

 

[platinum2]

falls flat? probly because it is so rich on fuel drowning its self, if it was lean atleast it would wind out

 

[gearhead13]

falls flat? probly because it is so rich on fuel drowning its self, if it was lean atleast it would wind out

I dropped from a 145 to a 140 main and it winds out to 9k rpm now. I was running 132.5 mains with the 1170. I am trying to decipher the Innovate data graphs to figure out where I am at now. Hard to tell because I don't have rpm or any other data input to tell me when it is at wot. The data logger costs $500

 

[gearhead13]

Pulled the top end apart to fix a base gasket leak. Did a light hone job and added a 0.010" base gasket to lower compression by ~.5 points (to 10.5-1) as far as I can tell from what I have read:
http://www.johnmaherracing.co.uk/enginecalc.htm
Also degreed the cams 108/108, feels much snappier. Wanted to lower cranking compression for easier starting and not worry about pinging if I have to run 91 gas.
Getting ready to install the RS38 carbs