![]() I also sprayed the crank case gaskets while the engine was running. With the shroud off and the pull-starter unbolted, I was able to wet (spray with WD-40) the top seal, quickly put the recoil in place, start it, remove the recoil (while running) and then gun it. My fingers are tired - I think I have covered everything here. Does this jet have a check-valve or something in it, and does this behavior make sense? The jet is pressed in and a replacement doesn't come with the kit. It's not a straight through hole (there are crimp marks on the inside of it like it is a multi-piece assembly), and it seems to scatter the carb cleaning fluid differently each time I spray. When rebuilding the carb I noticed that the main jet is not consistent when I try to shoot cleaner through it like most jets that i've cleaned. * Failure only takes about 5 minutes when started cold. * During testing, the unit is consistently held stable on a level padded surface on a concrete floor. * Everything is clean as a whistle on this unit. * Spark is strong - even when the engine is hot. ![]() * Tried several different two-stroke mixes - it currently has 3/4 tank of 50:1 Stihl oil to good-quality (no ethanol) 89 octane per the manual - no difference. * Cleaned spark arrestor - also removed it altogether - no help * Cleaned and inspected fuel lines - they are in great condition. This had little impact on transition or high throttle performance. Best operation (idle) is close to 1-2 turns out per the manuals. * tried a wide range of idle mixture settings. ![]() I believe that every port passed cleaner normally (except possibly the main jet - see paragraph below). * I've loosened the gas cap in case a vacuum was building up - no help * Compression "feels" good, and it never feels seized Just when I think maybe I fixed it, it goes bad again. The behavior pattern I've described here is the closest I've been able to determine, but sometimes it just seems to defy the pattern - just acting flaky and unpredictable. The carb is a Zama and it has no high speed mixture adjustment. The idle is always fine, and if I can get it to full throttle, it sounds great there as well. Sometimes, tipping the unit on its side when idling will immediately stall the engine.The unit seems to need to cool back down before I can get it to run semi-normally again. I am familiar with engine tuning, and it definitely acts lean - also, running partially choked will consistently make it run GREAT. Hesitation (bogging) increases, and if I don't baby it, it will stall. The unit starts fine, and once it warms up a bit, it will transition ok - not stellar, but maybe a little hesitation - but it won't stall.Īs the unit runs longer, it starts to misbehave. I have seen some of these engines show symptoms that you think is carb related, but was actually from a wrongly activating speed limiter in the ignition module.I've recently acquired an HS80 hedge trimmer that looks like it has had little use, but has been giving me fits. You can do it only by fitting another working module. But you will need a pressure gauge to ensure you don't overdo it, since that could cause flooding Post Script: Do check the ignition module. If they are turned out beyond a point (L especially) I found the engine is starved of fuel when the throttle is pressed.Īnother remedy is to increase the metering level by bending the metering lever upwards. One important thing to remember is don't turn out the H and L screws more than 2 turns. The FS55s that I have seen are highly prone to carb problems from fuel issue(in my limited experience)ĥ0% of the time a complete strip down of the carb, including the H and L screws and a thorough cleaning using soap water, followed by carb cleaner and a blow thru with air has been a sucessful cure. I have not used or opened up an HS45, but I do know it shares the same series of engine as the FS55 trimmer.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |