084 - gettin it cranked without breaking a hand

[timberwolf]

I have taken keys off and friction fit flywheels before, and it has worked fine, but I do worry about what happens if the chain break is hit at full RPM. However on the up side of that I would rather have the flywheel slip a few degrees than have the crank snap. As long as you are aware of the possibility of timing going out it should not be a big deal.

 

[PES+]

I had 2 that broke chains and jammed and pulled the thread clean off the end of the crank It is why in the past I moved back to carrying my rotating mass in the crank itself and going lighter on the flywheel

 

[troutfisher]

Take a little Valve lapping compound and put it on the Taper, run the flywheel on the taper until it is a tight fit, cleanup both tapers. Line up the slots, tap the flywheel, thne torque the nut down...no need for a key if your taper is doing its job.

I learned this at the Kart racing site...no need for offset keys to change timing on those race briggs engines.

What kind of Race saws you run? Poulan?:hmm3grin2orange:

That's what I did to my briggs race engine, raced all last season and it's still holding. My engine has an electric starter, and the ring gear is on the flywheel. Just the taper lock is very stong.

 

[Tzed250]

Tdc

A trick that i use to start my SP125 is to position the piston at TDC, press the decomp, relax the starter rope, then pull like h$ll. To start a 500cc two-stroke single dirtbike, this is the method that most use. A 500 that you let kick back will throw you over the bars, or put a hole in your boot. The TDC method lets you maximize the kinetic energy in the crankshaft, giving it the best possible chance of overcoming the combustion pressure.

 

[RiverRat2]

It will, if workload permits I'll make one tomorow. I'm real anxious to get this taken care of.

Seller turned out to be very fair, reimbursed more than enough even if it end up needing a carb kit. I'll refund what I don't need, dealing with a fair eBay selller doesn't happen often enough.

I have access to a puller, just cant do it till later this afternoon or tomorrow morning???? I will PM you in a minute

 

[flht01]

she's alive

I got a chance to pull the flywheel move it to the correct keyway for the 3 post module. It made all the difference, cranked easy cold and hot. Can't thank everyone enough for the help.

I set the carb and have a few questions. To get it to ramp up without any hesitation I ended up a full 1-1/2 turns out. Throttle response is good but if you run the rpm's up close to max and let off, it will drop back about 200 rpm below the normal idle speed (set at about 2000). Sometimes it will return to normal idle speed and sometimes it will die. Any less that the 1-1/2 turned out on the low speed screw and it will bog a little when you hit the throttle. When I was adjusting the low speed screw, I was changing the idle screw to keep the rpm around 2k.

Before I started setting the high speed, I went back and reread all the carb post on the 084 but I'm still a little concerned with the high speed screw. I started withthe screw 2 turns out and it tach'd about 7k. I ended up turning the screw in until it was up around 11,700 but the screw isn't but a little over 1/2 turn from closed.

I worked back and forth between the low speed and high speed to make sure one setting didn't affect the other. The saw seems to be running good but I'm a little nervous about getting it set right.

Opinions?

 

[Lakeside53]

Don't run the H end at 1/2 turn out. Until you have it all figured out, set it at 1 turn out at least. If you have the rev limited ignition, you may be bouncing off the limiter and are way too lean.

Which coil or coil/trigger do you have installed??

Is your air filter clean? Do you have the HD filter (and which version - dry or oil?) or the flat version?

2000 is a bit slow.. I like mine at about 2250-2500. Dying after idle from from H speed running is usually loading up from too rich, but it can be a bad carb metering diaphragm and a host of other little issues. Which carb do you have?

 

[flht01]

Don't run the H end at 1/2 turn out. Until you have it all figured out, set it at 1 turn out at least. If you have the rev limited ignition, you may be bouncing off the limiter and are way too lean.

Done, set at one turn out.

Which coil or coil/trigger do you have installed??

Part number stamped on the coil is 1124 1308

Is your air filter clean? Do you have the HD filter (and which version - dry or oil?) or the flat version?

Cleaned it before starting, 3 piece HD filter. Part number on the main filter is 000 120 1600.

2000 is a bit slow.. I like mine at about 2250-2500. Dying after idle from from H speed running is usually loading up from too rich, but it can be a bad carb metering diaphragm and a host of other little issues. Which carb do you have?

I think anything above 2100 caused the chain to creep but I'll check it again. Carb is a Tillotson, couldn't find any numbers on it but I can pull it and check if it will help.

 

[Lakeside53]

First, the good news... you have the non-rev limiting ignition. It's likely that it was changed from a -1306 and the flywheel left in the wrong slot. The max permissible engine speed with bar and chain is 12,500 (subject to what is in the other threads you read). I like abut 12k...

So... why isn't it able to get to rpm closer to standard carb settings? as you are richer than normal (you are needing to lean more), most likely your carb needs a good cleaning, metering arm adjustment and/or and a new kit, but check the ignition coil gap. Use a business card as the gap measure between the coil and the magnet. Also - before you do anything, try it without the air filter - the old form of the filter gets blocked and you can't see it or clean it. I recommend you just get a new filter set of the fleece type - 0000-120-1654

Your carb is likely an HT-7A. Great carb...


Part of your stalling at idle will be solved by turning up the idle. You are too low and need to replace the clutch springs (cheap). Take off the clutch (you'll need a big breaker bar - they can be a bit?ch) and do it in vice - the springs are strong... so expect a struggle...

Another cause of stall at idle after a high speed run is boot collapse - the sudden change to lower pressure in the boot can make it colapese slightly effectively enriching the mixture (less air). Look for a soft or cracking boot.

 

[t_andersen]

Also - before you do anything, try it without the air filter - the old form of the filter gets blocked and you can't see it or clean it. I recommend you just get a new filter set of the fleece type - 0000-120-1654

I second that. I just went through the same thing, I couldn't understand that I had to turn the H screw to a position only 1/2 turn from stop on my 084. However, without the filter I had to tune it almost 2 turns from stop. I had cleaned the filter beforehand but that wasn't enough. I bought a new filter and it helped.

 

[flht01]

Thanks for that info, I went ahead and ordered a carb kit. I've got the clutch off and will change the springs. While I'm this far into it, I went ahead and pulled the oil pump to replace the aux oiler cable and oil take hose. Looks like someone had forced the oiler adjustment screw enough to break the end off the pin so I'll get it too. It'll be a few days before I get everything put back together but will report back with the results. I pulled the muffler cover and checked the pc and all's well, was a little nervous with the hs screw setting.

Last question for a day or two, what's the correct metering arm setting?

 

[Lakeside53]

It's either level with the top of the carb body, or the bottom... can't remember, but it's real obvious when you see it. The factory setting will be close. Check the main jet size to see if anyone has messed with it (it's stamped on the top of the jet).

 

[CrazyCarl]

Timing

I agree! Look for 2 slots in the flywheel. If not,,,,possible wrong flywheel or coil.Check numbers.Also I ran into one(not Stihl) that had run to rich a mix and the carbon build up was so thick that the piston was hitting the build up.carbon build up results in higher compression,tho I doubt this is the problem.Go with timing on this one!

 

[CrazyCarl]

Flywheel

I suggest putting the nut back on the shaft so as to protect the threads,wedge a wooden wedge under the flywheel and rap the nut.If it does not come loose after one or two light raps then use a puller

 

[Lakeside53]

Hey Carl - read on... he already did the flywheel and got it running!

 

[flht01]

Part two of my last question for a day or two:

The parts list shows the metering diaphram against the carb body and gasket on the cover side, opposite of the others I've put in.

When I pulled the carb cover off, the gasket was against the carb body and metering diaphram against the cover, the way I've always put them in.

I put it back together the way it came apart but thought I'd ask, this is the first HT-7A I've done.

 

[Lakeside53]

If you're looking at the Stihl IPL, it's just a strange perspective. You did it correctly.

 

[flht01]

I agree! Look for 2 slots in the flywheel. If not,,,,

Hey CrazyCarl, it leaves a lasting impression when it keyed wrong :hmm3grin2orange:

If you're looking at the Stihl IPL, it's just a strange perspective. You did it correctly.

Sounds good, thanks.

Walked in our local dealer this evening with a list of part numbers. Keep in mind this dealership has been in the current owners family for at least 2 generations and reminds me of going into an old hardware store. He had all but a couple of parts for this saw, some of them had been in his inventory for years. I know that doesn't sound like much, but there probably isn't another 08* saw in this area. Nicest most helpful people that really know what their doing. Just had to share.

Now I've got to go tackle the clutch springs. Wish me luck.

 

[Lakeside53]

Now I've got to go tackle the clutch springs. Wish me luck.

Check the shoes for elongation of the spring holes.

 

[flht01]

Check the shoes for elongation of the spring holes.

Spring holes were still good. The old springs "looked" good but I could sure tell the difference when I grabbed hold of the new ones.

Replaced the oil tank hose while I've got the oil pump off, no problems with that either.

I noticed the hose from the oil pump to the bar feed was stiff so I just cut it when I removed the oil pump earlier.

There's got to be a trick to getting the new one installed. I took one look at it and called it a day. I'm still scratchin my head on it, maybe soaking it in boiling water will soften it up enough. :help: