Author Topic: stihl 028 wb (Read 8106 times)

mountaineer · « **on:** March 03, 2008, 08:30:04 pm »

i lost one of my av mount bolts today and ripped the rubber mount that goes from the carb to the piston. gonna get a new one soon but was wondering whats the easiest way to put it back on. seems by looking it could be tricky. i am assuming carb side first then try to get it on the other side and tighten the clamp. anyone got any suggestions on how to go about it. thx

joe_indi · « **Reply #1 on:** March 04, 2008, 04:30:08 am »

If you do not want to separate the tank housing from the crankcase to replace the manifold, this is the alternate way to do it:
Remove all the AV mounting screws.This will help you get some more room to work.
Before you do anything else check the impulse hose since it too could get damaged from a loose AV mounting.
Fit the manifold onto the cylinder and tighten the clamp.
Then fit the carb end of the manifold.
Refit the AV mounting screws and carb.
Joe

mountaineer · « **Reply #2 on:** March 04, 2008, 09:18:25 am »

thx i was thinking the carb side first but i havent done this before so i will try crankcase side first. looks a little tricky either way. now im waiting on the part. i went to the local stihl dealer and they said the manifold would be 24$ and labor would be 55$ an hour with about an hour time to do the job. for 79$ i could easily buy a parts saw and have a lot of extra parts. it seemed a little high in price. what do you all think? thx for the info

sawguy21 · « **Reply #3 on:** March 04, 2008, 09:54:08 am »

The price sounds about right for that job. If you try it, be patient so you don't have to do it a second time.

mike_van · « **Reply #4 on:** March 04, 2008, 01:25:54 pm »

Take the carb. right off, there's a little metal ring inside the rubber neck - Take that ring out, then wad up the rubber neck up & push it through towards the head. Reverse the steps to put the new one in.

mountaineer · « **Reply #5 on:** March 05, 2008, 06:00:53 pm »

just put it together. not bad at all. i put the crankcase side on first. it was easier to fish the other end through the carb hole. i put it all back together and when it runs it hesitates some. it also bogs when i give it full throttle. need to adjust the carb? thx for all the help folks.

Kevin · « **Reply #6 on:** March 05, 2008, 07:43:41 pm »

High and Low speed jets are one turn out from a lightly seated position.

Adjust the idle speed just below clutch engagement.

Adjust the low speed to obtain highest idle then turn it counterclockwise 1/8 turn.

Adjust the high speed to obtain highest rpm under load.

Adjustments to be made with a clean air filter and a warm engine.

You should be using a tachometer.

mountaineer · « **Reply #7 on:** March 06, 2008, 07:02:15 pm »

i had put a newer air filter on the saw when i worked on it. i thought that might be the problem. sure enough i switched it back and she purrs once again. i don't know whats wrong with the new filter. oh well.

mountaineer · « **Reply #8 on:** March 06, 2008, 07:26:41 pm »

i bought a not in the greatest shape 028 av super and took the part off of it. i tried to crank it a few times and it did not start.(before i took the part off)the lady i bought it from had no idea if it ran so it might be salvageable. is checking the compression the best way to see if its worth fixing? and if so what kind of compression tester should i get? thx

joe_indi · « **Reply #9 on:** March 07, 2008, 08:44:53 am »

Quote

it also bogs when i give it full throttle.

This is a frequent problem on some Stihl saws (028, 038, MS380, MS381)that have the choke shutter in the air filter instead of in the carb.
This type of choke is held back by a spring.If the spring is weak or loose, when the engine is revved up, the higher air flow causes the shutter to go into the 'close' position.
In the worst cases it remains closed until the engine dies from flooding.
Usually it closes at full revs, opens as soon as the revs come down, and keeps doing this as long as you have the throttle fully pressed.
If you didn't know, the symptoms would make you suspect the ignition system.
The cure is simple.Either tighten the spring a bit or use the spring from your old filter, since it seems to work fine.

Joe

mountaineer · « **Reply #10 on:** April 05, 2008, 08:37:39 am »

so i finally got my 028 av super i ordered off of ebay.(no problems there the guy that sold it to me is super nice) but one thing it is doing is when i throttle it it hesitates. i have to work the throttle up and down a bit to get it to rev. once i get it going it runs well. it does seem to bog a little more than my wb i have. to test it i used the bar and chain off my wb to get a true idea of how it runs. the chain is sharp. any ideas on what might be the issue? thx andy

Kevin · « **Reply #11 on:** April 05, 2008, 06:04:36 pm »

I would adjust the carb first,then tear it down and clean it if need be.

mountaineer · « **Reply #12 on:** April 05, 2008, 06:18:46 pm »

kevin do you mean adjust like the instructions you gave earlier in this post? i have never adjusted a carb and i am a bit tentative because i would hate to make matters worse. i've heard you can ruin a saw by not having the right settings on the carb. but the settings it has now might be bad so...

Kevin · « **Reply #13 on:** April 05, 2008, 06:44:56 pm »

I like using a tach, it's your call.

You can get someone to tune it but you should learn if you are so inclined.

mountaineer · « **Reply #14 on:** April 05, 2008, 06:47:21 pm »

i would really like to learn. where would i get a tach?

Kevin · « **Reply #15 on:** April 05, 2008, 06:54:38 pm »

I know Bailey's have them ...

http://www.baileysonline.com/search.asp?skw=tachometer&PageNo=1&x=18&y=6

http://www.forestryforum.com/board/index.php/topic,8047.0.html

I have the Stihl DET-303 but I don't think they make that one any longer.

leweee · « **Reply #16 on:** April 05, 2008, 07:12:46 pm »

Quote from: mountaineer on April 05, 2008, 06:47:21 pm

i would really like to learn.

Check this page

MADSENS carb tuning

mountaineer · « **Reply #17 on:** April 05, 2008, 07:57:21 pm »

that is really good info leweee. thx. do you know what the high rpm is for the 028 av super?

leweee · « **Reply #18 on:** April 05, 2008, 11:46:05 pm »

Shop Manual says 13,000 rpm. maximum with bar & chain tensioned.

mountaineer · « **Reply #19 on:** April 06, 2008, 08:52:43 am »

should i tach and adjust it with the bar and chain on or off? oh by the way leweee, don't let the !@#$%^'s get you down. i like the saying. gonna remember it. thx andy

mountaineer · « **Reply #20 on:** April 06, 2008, 09:02:26 am »

hey leewee, here's a good one-

Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?

leweee · « **Reply #21 on:** April 06, 2008, 11:34:22 am »

Andy....... had to Google that one......us beavers have a hard time keeping up with them Woodchucks.

Thanks for that one .

mountaineer · « **Reply #22 on:** April 23, 2008, 08:05:56 am »

so i have my tach and i'm ready to go. kevin when you say under load do you mean while cutting? or just full throttle?

leweee · « **Reply #23 on:** April 23, 2008, 01:16:34 pm »

full throttle with bar and chain tensioned.....not in the wood.

mountaineer · « **Reply #24 on:** April 23, 2008, 06:06:51 pm »

idle is 2930 and full throttle is 12540. i adjusted it first by following madsens carb tuning like you advised. now the taching. i did back the low down a little after i put the tach on but it seems to struggle a bit when i do so i put it back up to 2900's. i have not touched the high though. do yo think that 12540 is a good high end or should i adjust it to get max. an if i do that am i risking the engine?

leweee · « **Reply #25 on:** April 23, 2008, 11:32:43 pm »

if the chain stops traveling at that idle speed,and it preforms well in the wood you should be good to go.

mountaineer · « **Reply #26 on:** April 24, 2008, 08:52:02 am »

to be honest leweee, i still think it bogs more easily than my wb does. would i need to get the rpms a little higher?

leweee · « **Reply #27 on:** April 24, 2008, 10:43:30 am »

Quote from: joe_indi on March 07, 2008, 08:44:53 am

Quote
it also bogs when i give it full throttle.

This is a frequent problem on some Stihl saws (028, 038, MS380, MS381)that have the choke shutter in the air filter instead of in the carb.
This type of choke is held back by a spring.If the spring is weak or loose, when the engine is revved up, the higher air flow causes the shutter to go into the 'close' position.
In the worst cases it remains closed until the engine dies from flooding.
Usually it closes at full revs, opens as soon as the revs come down, and keeps doing this as long as you have the throttle fully pressed.
If you didn't know, the symptoms would make you suspect the ignition system.
The cure is simple.Either tighten the spring a bit or use the spring from your old filter, since it seems to work fine.

Joe
[/quote

when reving the saw ,watch the choke flap to see any movement...

did you clean & rebuild the carb?....check fuel filter & line....impulse line from crankcase to carb.

mountaineer · « **Reply #28 on:** April 24, 2008, 11:25:01 am »

it runs good, just not what i thought it would be with the extra cc's. i don't think it's much more than some tweaking of the high jet.

leweee · « **Reply #29 on:** April 24, 2008, 03:23:40 pm »

when they were both new you would notice a bigger difference.

now that they are pensioners 4 or 5cc's isn't a biggy.

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Author Topic: stihl 028 wb (Read 8106 times)