help 025

[buck futter]

I have a stihl 025 I have been tinkering with. I switched over to the RS chain and have done a muffler mod that I am pleased with. my only complaint was that it didn't have an ajustable hi speed jet (wt-283B) so I saw a wt-286A on ebay for sale and picked it up. The saw started and ran great except it was a little rich and wouldn't top out. I put on the new carb and tested it it wouldnt idle but ran fine if you kept it alive despite any adjustments I made. I must add the new carb has a connection for the external primer bulb that is on the easy start models. In the manual it says a possible culprit is the intake flange gasket so I took off the carb bought an new gasket and also called walbro about blocking off the manual pump intake, the tech said if I blocked it off the carb would still function fine, I told him of my problem and he told me to clean the main jet. I tore the carb apart took out the main jet and inlet needle valve cleaned both with mineral spirits and then isopropyl alcohol the inlet valve had red stuff on the point but nothing much for any indentation. I reassembled everything and then used gasket paste and installed the carb fired it up and it still does the same thing.
Can any one help me of give me some things to check

Thanks in advance

Lucky

 

[HiOctane]

Looks like you are running too rich.Did you check lo speed adj.,should be 1 to 1 1/4 out.Also check your inlet lever if its at the right height.Your air filter is not too dirty?

 

[buck futter]

checked

the hi and lo speed jets were originally set at 1 turn out, I can turn them in and out and only see a little more or less smoke but no change in idle speed. I have the Idle screw turned all the way in and it should be at a very high idle but instead it dies out. I have recently cleaned the air filter and with the other carb it ran perfect. the input control lever seemed level I could put the on from the 283 into the 286 the whole assembly is the same part number

lucky

 

[buck futter]

anyone?

 

[medcave]

Well since you said anyone. I'm an automobile mechanic and know virtually nothing about 2 stroke carbs, but your statement about putting paste on the gasket troubled me. In the automotive world gaskets always go on dry without any sealers since they can clog up ports and air bleeds. Is it possible that's what happened here? Forgive my ignorance if I'm way off base.

Dave

 

[CNYCountry]

I wonder if there are limiter caps on the carb that are keeping you from turning the screws far enough to get into the right range, this could be aggravated by the fact that your muffler is opened up a little. See if you have limiter caps that need to be removed.

Sorry if you already tried this...

 

[fishhuntcutwood]

I'll echo what CNY said. I was thinking the same thing.

Jeff

 

[buck futter]

No problem, I'll take any help I can get however I don't believe that it could be the problem the glue was placed on the gasket that goes between the output side of the carb and the metal spacer that goes to the rubber intake boot. there is only one hole and its a biggun. I suspect that it may be the inlet needle or maybe its seat, is the culprit. I did a search on here to see if this could cause the symptoms and any time it was mentioned the person never finish off the post to say what fixed the problem. Its like reading a book and having the last chapter ripped out. anyway thats why I need some info. it is running rich and that is what kills it so I would think there would be a short list of potential causes. Thanks again for your reply

Lucky

 

[buck futter]

no limiter caps just the jet screw with a spring.

Lucky

 

[medcave]

No problem, I'll take any help I can get however I don't believe that it could be the problem the glue was placed on the gasket that goes between the output side of the carb and the metal spacer that goes to the rubber intake boot. there is only one hole and its a biggun.

Ah I understand. Outlet side wouldn't cause that sort of problem.

I suspect that it may be the inlet needle or maybe its seat, is the culprit.
Lucky

That's very possible. I've seen several references to how easily the seats are damaged from overtightening the needle. I've got the Chainsaw Service Manual on order and will see if it covers your problem, if just to satisfy my own curiosity.

 

[buck futter]

update, still need help

yesterday I tore down the wt-286 and the wt-283, the spring for the 286 seemed to be shorter so I figured it must be not pushing the needle to its seat so I switch with the known good one in the 283 both of the inlet levers are level. While I had the carb apart I used a can of compressed air to clean out the passages and jets I also tested the inlet needle when it was back together by using the compressed air in the fuel hose barb and pressing the diaphram to let some air by it was the same on both carbs. I put the 286 on the saw lo and hi needles one turn out and the idle screw all the way in to hold the throttle part way open I figured it would race if everything was right and I could adjust it. I started the saw and it did the same thing, doesn't Idle but runs ok if I blip the throttle or open it up.
My neighbor wanted a couple of limbs off of his maple so I put the 283 fixed jet carb back on and it started and ran fine. So its obviously the carb. what else can I do? Does anyone here have any ideas?

Please help

Lucky

 

[buck futter]

thanks gents

I finally got the old girl running with the new carb. and I certainly learned alot in the process.

Lucky

 

[ray benson]

So what did you do to square away the problem?

 

[medcave]

Yeah, where's the last chapter in the book?

 

[buck futter]

well its one of two things

I tore the carb apart again and removed the welch plug and cleaned out the secondary idle jets, but at the same time I replaced the main jet. I don't understand what could have been wrong with the main jet the disc looked ok. but anyway it sits there and idles and revs up fine. I only ran it for a minute so I will have to put it in wood to make sure its all ok. But I think thats all she wrote
Thanks again to those that did help me.

have a good one

Lucky