Author Topic: Bike Won't Run right (Read 1636 times)

theslayedsaint · « **on:** March 20, 2015, 06:13:41 PM »

Ok guys,
for all the folks that have been following my build for better or worse! sorry guys been taking over the site this week.
I've got the bike running took it on a test ride and she did ok, nothing crazy happened no smoke or anything like that but still can't get her to run right. any help would be great i'll keep looking. guessing i can find something about the spark plugs that should help me understand whats going on.

symptoms
-wont hold a steady idle
-stutters when accelerating at mid rams
-sometimes i can get it to idle and run with no throttle other times i have to help it.
-spark plugs look pretty black

What I've done
-timed and set the points hits right on the f when i use timing light (should I change that?)
-synced carbs to the best of my small abilities got them all to run almost at the same spot on the sync tool.
-set air screw at 1.5 turns out

Bike
-4-1 exhaust
-pods
-cleaned and replaced parts on carbs
-rejet to mains 118
-slow jet 42
-running 849cc kit with a webcam 63a

Davez134 · « **Reply #1 on:** March 20, 2015, 08:15:08 PM »

Surging, inconsistent idle is usually because of synch being off (which you said is not) or vacuum leak from rubber carb boots. Plug color will only tell you what the bike is doing at a certain throttle position. For example, if you let the bike idle and shut it off, then you can read them for idle mixture. If you run 3/4 throttle then hit kill switch and come to stop with engine off you can see that range. The stuttering in midrange may be you have too small mains. You may be having to "help" it idle because your slow jets/idle mixture is too rich, fouling plugs. Hard to say exactly without actually seeing bike. Give this a read and see if it helps.

http://forums.sohc4.net/index.php/topic,5410.msg2455.html#msg2455

Also, are you 100% sure you got that cam timed correctly?

mystic_1 · « **Reply #2 on:** March 20, 2015, 08:17:07 PM »

Tell me about your coils.

Stock? In good shape?

Have you carefully examined the plug wires right where they enter the coil bodies? The insulation tends to start failing there once it's aged enough to start becoming brittle.

Some of your symptoms suggest possible intermittent misfiring on one or more cylinders.

mystic_1

grcamna2 · « **Reply #3 on:** March 20, 2015, 09:37:03 PM »

The fuel tank is clean w/o any debris getting into your carbs.? A good way to check is to remove the petcock bowl and see what's in there.The dirt in the tank will eventually find it's way into your carbs and clog the jets up a bit.

flybox1 · « **Reply #4 on:** March 20, 2015, 09:56:43 PM »

Your pilot jet is way too big. Drop to a 40. Leave your mixture screws where they are.
Put in a clean new set of ngkd8ea plugs. Old.dirty plugs won't work.
Start it. Let it idle 2-3 minutes.
Pull the plugs.
Line them up 1-2-3-4. Take a picture and report back how it started and idled.
Don't ride it, don't rev it. Start. Idle. Picture.

While you are in your carbs...Pull your emulsion tubes, and clean them again. Spray carb cleaner into all jet passages.

theslayedsaint · « **Reply #5 on:** March 20, 2015, 11:33:03 PM »

Sounds like a plan thanks for the detail list! Can I get spark plugs at like auto zone or somthing?
I guess it was the wrong call to pay $30 for ngk iridium plugs

mrfish2 · « **Reply #6 on:** March 21, 2015, 12:16:05 AM »

Quote from: theslayedsaint on March 20, 2015, 11:33:03 PM

Can I get spark plugs at like auto zone or somthing?

Sure you can! All the local auto parts shops should have them in stock for around 2 to 3 bucks a piece.

ekpent · « **Reply #7 on:** March 21, 2015, 05:22:52 AM »

What year is this engine and are you using round top carbs or the later year pumpers ? Have you used/manipulated the idle screw to make it better or is the bike constantly searching for an idle ?.

DH · « **Reply #8 on:** March 21, 2015, 05:53:29 AM »

clear tube method, verifying the fuel level isn't too high? (sometimes idles, sometimes needs help, black plugs)........+1 on emulsion tubes check.

flybox1 · « **Reply #9 on:** March 21, 2015, 07:21:32 AM »

Yes, you should be able to get the D8EA plugs at any auto store.
Your 42's are too big and fouling your plugs.

Put your bike specific info in your signature. Then people who aren't following your other threads won't have to search for it, and you won't have to type it more than once...

theslayedsaint · « **Reply #10 on:** March 21, 2015, 10:37:54 AM »

Quick qustion am I missing these brass "plugs"? On carbs 2-3 they are both there but on 1-4 there isn't one on the outsides.

ekpent · « **Reply #11 on:** March 21, 2015, 11:16:04 AM »

That is normal--no problem there.

theslayedsaint · « **Reply #12 on:** March 21, 2015, 12:29:15 PM »

ok results are in.
carbs looked fine but i still went ahead and cleaned everything just to make sure. replaced the slow jets with 40#
ran the bike for around 3 min, took a min to start but i'm guessing thats just because i had to get the gas back through the carbs. when it started it sound way different not as loud and "angry" as before. it keep its idle until about 2-3 min in when the rpms went up and I had to adjust the idle screw. thoughts? only other thing is the rpms jump a little (900-1400) but that could be my cluster also.

theslayedsaint · « **Reply #13 on:** March 21, 2015, 06:18:36 PM »

any thoughts on what to try now? still running bad

theslayedsaint · « **Reply #14 on:** March 21, 2015, 06:55:56 PM »

any thoughts on if it could be this http://www.salocal.com/sohc/tech/carb/asmpg_mgs/sldrrasmbl.htm
the main needle jet clip position?

flybox1 · « **Reply #15 on:** March 21, 2015, 07:12:26 PM »

Rpm increase is normal when the bike warms up. Turn your mixture screws 1/2 turn RICHER and repeat. This time, let the bike idle for 4-5 minutes.
When you take a picture of the plugs, we need to see the tip, and the color of the insulator.
Side shots don't show us anything.

Do you have your old iridium plugs still? What color are the tips? Picture?

ekpent · « **Reply #16 on:** March 22, 2015, 05:59:02 AM »

If that engine and the bores are brand new you are not doing it any favors by letting it idle to long or too much. Best thing for it is to try and give the rings a proper break in if you can ride it under load for awhile.

theslayedsaint · « **Reply #17 on:** March 22, 2015, 09:56:04 AM »

Thanks for all the info guys! I've got a motorcycle mechanic (same company that did the valves and bore) to help me look at it. i'll let you guys know what we come up with.

theslayedsaint · « **Reply #18 on:** March 22, 2015, 07:27:07 PM »

ekpent I owe you a beer!! no a 6 pack!!!
I finally today was like #$%* it I'll just take it out and see what the hell happens, while ridding I played with the idle while riding and I almost fall off the bike.. It took off and had so much power.
So my thought is I know nothing about old bikes or not enough about riding them. It needed to warm up and I just needed to use the damn idle. So now I'm wondering if I should change back to the 42 slow jet or keep the 40. Never felt better. Ohh one more thing is my leg suppose to be on fire from the oil tank?

flybox1 · « **Reply #19 on:** March 22, 2015, 08:59:46 PM »

Only the plug color can tell you if 42's are correct.
If 40's, and 1/2 turn richer from your previous 1.5 turns made the plug insulator a nice tan color, then this setup is correct.
If the plugs w 40's are still pretty white, then 42's just might be better...

ekpent · « **Reply #20 on:** March 22, 2015, 09:00:02 PM »

If the oil tank does not have a side cover on it it can feel very hot and possibly burn a bare leg. Don't ask how I know.

News:

Author Topic: Bike Won't Run right (Read 1636 times)

DH