Stihl fs 90 ave trimmer
- Thread starter rob066
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The Hose on your picture is 4117 358 7700. But it is a real old part and likely nla.
Thank you. That part number was extremely helpful. I'm very thankful you took the time to answer my question. Stihl dealers say this line and the carburetor is obsolete no longer available. A few eBay sellers sell these old stock new parts, thankfully I found the only seller who only had 2 fuel lines left.
The trimmer has 110 psi compression with engine warmed up, that's the only reason I'm investing money in it.
110 comp seems low, most modern 2 strokes won’t run at that reading.
Oh yikes. What should the compression be on A good trimmer engine? I was going by lawnmower engines being 120 psi being A good engine. I may have made A huge mistake.
4strokes can run at lower comps, in my experience, 2 strokes have a hard time starting and tuning the carb at the same readings. Piston ported 2 strokes tend to be finicky at lower comps. Pull the muffler and check the condition of the piston is always a way to be sure.
No problem, your welcome.
I hate to bother you again, but you have the number for the ignition coil?
The ignition module was 4117 400 1300. Do you have the old Teikei carburetor on your FS 90 AV? Later versions had a Walbro WT-38B which was superseded some time to the WT-189B. But I have no more information about it and the air filter, shroud and filter housing was also changed for the use with the Walbro carburetors.
It has the Walboro carb. WT 38 A5 is stamped on the side of it. I ordered A 4117-120-0605 and it looked like the old one and fit. It ran until it got good and warm and kept stalling. It has the square 4114 124 3605 air filter cover on it. That reminds me I need to find A air filter for it if I can find the part number. Someone just cut A piece of cheap foam pre filter to put in it. I discovered the fuel line inside the fuel tank was pitched and it is sticky. I hope the new fuel line fixes it, if not I'll have to figure out why it sputters when I give it just A little throttle and clears up at wide open throttle, and why it stalls after getting good and warm.
The air filter elements (2) may be nla, don`t know exactly. So you have to find old stock if possible or create something by yourself. Did you tune the new carburetor? Maybe it need tuning to improve the running caracteristics. The air filters are 4114 124 0805 and 4114 124 0806.
T
Thank you. Yes I turned the H carb adjusting screw. It idles fine, so I didn't turn the L carb adjusting screw. When I turned the H clockwise while at wot, it speed up the rpm but it stalled. When I turned the H counterclockwise, it lowered rpm and smoked but at least kept running at wide open throttle. Aggravates me when I give it A quarter throttle or half throttle, it sputters and almost stalls until I give it full wide open throttle. So it only stays running at idle or full throttle. I may have got A defective carb with it being old stock. Maybe it wasn't getting proper fuel with the fuel line pinched. I'll know when the new line gets here. I hope I don't have A vacuum leak around the crank seals. The 4117-007-1050 seals and gasket kit is $40. I already have $62 in the new carb. $15 in the fuel line. I took off the muffler and cleaned what little carbon was around the exhaust port, and burned out the muffler with A torch. No spark arrestor screen was present.
What compression cold ,and do you pull till it stops rising?
Common problem on these line trimmers is the muffler exhaust screen blocks up. After that, they run like junk or don't run at all. Clean that well. I've fixed half a dozen that way.
Cold compression test wide open throttle is 160psi. needle on gauge stopped moving at 12 pulls, I pulled 15 pulls for good measure.
If it has the teiki carb on it its probably made by
shindiawa like my fs96.I have a new carb kit in it
and it ran great for 2 years and now not delivering fuel
shindiawa like my fs96.I have a new carb kit in it
and it ran great for 2 years and now not delivering fuel
Perfect compression. The carb you put on is it OEM ? You replaced the fuel line? How exactly does it run improper can you do a video?
Unless it is A counterfit carb it is OEM. It came in stihl branded packaging, has Walboro stamped on the diaphragm cover. No I haven't, I am waiting for the fuel line to get shipped and delivered. I can do A video if the fuel line doesn't work. Probably be A week before it gets here though.
So the fuel line came in yesterday And it was genuine stihl 4117 358 7700. As seen in my picture in original post, the line is as round as the filter itself, and the other end is as round as the fuel tank grommet. Well the new fuel line is only half as round as the filter and the fuel tank grommet. So I'm wondering if it will leak?
