ZAGNUT

My Feedback: (1)

here's my old echo 21.2cc trimmer engine. it's the 2 ring version with 3w electronic ignition. i just had to do the 6 bolt prop hub cause it looks cool. without ign or muffler weight is 37 oz. 8000 rpm with MA k series 16x6 and no muffler. i noticed that the oil seals cause a lot of friction so i removed them and replaced the front bearing with a rubber sealed unit and at the rear end i cut the crank off at the bearing and installed a plug in place of the oil seal. the engine is much easier to turn now but i have yet to run it like this, hope i'll gain some power.

Volture

My Feedback: (1)

Hmmm. I've got an old Echo (Kioritz) trimmer that someone gave me recently. Did yours have the pull-starter on the rear of the engine (that is, not on the trimmer shaft end)???

ZAGNUT

My Feedback: (1)

pull starter on the rear, mag on the front. came from srm-2100 model thats been around for quite a few years. good quality engine but i've got my eye on a 25.4cc that should have more power.

dave

Volfy

My Feedback: (23)

Zagnut, the 6-bolt hub may be overkill, but it sure looks great.

I like these small Kioritz engines. I have a single-ring 25.4cc that runs very smooth, though it does not have as much power as I would like. I have an Echo 25.4cc dual-ring that's been converted to CH Ignition right now. I may also look at converting an Echo 30cc later, but right now I have way more engines than I have planes.

jwv3

My Feedback: (1)

I've got a couple Echo engines on the back burner. After playing with poulan/weedeater engines, the Echo sure is nice quality. Forged steel con rod, copper coated (I'm guessing for heat transfer?), twin rings and nice looking castings. I have a couple 21.2cc's and a 58cc from a back pack blower. Hope to get them going soon, but like Volfy, I seem to have too many engines, too little time.

ZAGNUT

My Feedback: (1)

Volfy, do you mean the 30cc chainsaw engine?
a local saw shop has one of these, he wants $30 for the short block+carb. this engine splits horizontally at the crank like the 44 and 50 (bme) has rear exhaust and reed valve induction with the carb on the bottom of the case opposite the cylinder. should make a nice slim engine like the ryobi but lighter and perhaps more powerfull, there's also a 34cc version. next time i'm at the shop i'll pick it up. like my other conversions it'll have 3W ignition and a totally unnecessary but way cool 6-bolt hub.

dave

bm66

My Feedback: (3)

Hey guys just wondering if anyone had some model numbers of echo weed or backpack blowers in the 40-80cc range as i am chomping at the bit for my first conversion. some one told me that the first place engine line is a spin off of echo engines. or how about a motor from stihl in the same range. you guys seem to have done reasearch as to which models and would save me some time if i went looking for one at a pawn shop or small engine place. also does anyone have a website to get a reconditioned motor or outright buy one as all i would want is the motor and not all the other stuff attached to it as it would be removed anyway. point me in the right direction guys.......... [email protected]

jwv3

My Feedback: (1)

Unless you already have a unit, the Echo backpack blowers are more expensive than a commercial engine. I have a 58cc engine from an Echo PB-602. I picked up a couple low time 21.1cc engines from local shops. One is from an HC-1500 hedge trimmer can't remember the other.

Your best bet is to search local lawnmower/power equipment dealers that do service. Find a unit that has been smashed or run over but has a good short-block and go from there.

If you want to buy something new and tear into it, Poulan 46cc chainsaws are a decent price/performance ratio.

BME

Most of you guys probably know that Echo was our base engine for most of our engines and no one probably knows them better than I do. If you want to get the most out of your little weedeater engines please follow my directions exactly. Forget the 21cc and the 25.4cc echo and buy the 23.6cc. The older the model the better. They changed the transfers on the later models that did not work well. The first thing you need to do is machine the cylider base down as far as you can. The piston should very lightly bump the head but when you recut the piston crown it should clear again. You want about .015-.020 squish clearance. After this take a dremel and a degree wheel. You want the exhaust to open at 98 degrees ATDC and you want the intake to open at 108 degrees ABDC. Cut the exhaust port a little wider or as wide as the port is at the outermost edge. Work slowly and and check your progress many times so that you dont go to far. After you cut the ports be sure to radius the inside edge so it wont hang the ring. We have done hundreds of these conversions and with the battery ignitions they are turning 8500 on a 17x8 APC.



Keith
BME

captinjohn

ZAGNUT: How much does the 3w ignition system cost? Is the price about the same as other ignition systems? I bet they are high quality. Thanks Capt,n

Volfy

My Feedback: (23)

Zagnut, good deal on the 30cc chainsaw engine. Yes, that's the one. Keep us posted on the results. I'm very interested.

Keith, thanks very much for the conversion tips. I will have to keep an eye out for a 23.6cc. BTW, did you ever work out what the new compression ratio was after your conversion? Is it high enough that you have to run premium gasoline? Thanks again.

ZAGNUT

My Feedback: (1)

hi keith, nice to see an engine manufacturer taking interest in this forum and giving good, useable advice, thanks. i got two 21.2cc two ring engines for FREE so i ain't gonna forget about them! i do agree though that they dont offer a whole lotta power so i can allready see myself diging through piles of old engines in search of the holy aluminium grail! i've done quite a lot of porting on iron sleeves but have allways been afraid of chrome, what bit do i use, diamond? 8500 on apc 17x8 sounds killer!

captinjohn, i got 4 3W ignitions minus the plug boots for free so i swap these from engine to engine. from what i've seen , the price on these seem to be unjustifiably high. here on rcu i've read about a lot of breakdowns with these units but i've never had any problems, maybe time will tell. if i had to buy an ignition my money would go to ch for a synchro-spark. also the 3W pickup coil is huge and a pain in the butt to mount sometimes (see pic)

dave

Flypaper 2

Zagnut;
Iv'e Done a few chainsaw and a lot of snowmobile chrome and nickel cyls using carbide cutters with no problems. Just make sure you bevel the edge of the porthole, cyl joint with a strip of 360 emery cloth to keep the ring from catching but you probably knew that.

power-RCU

Hi, I have converted both the cs-3000 and the cs-3400 echo chainsaws. They both purr like kittens, One nice thing they hand start with a good flip!! The cs-3400 has what is called slope advance timing module it has an extra foot on the ignition module, echo says it retards the timing to about 15 degrees at start up.It doesn't seem to aid in starting but it sure idles smooth.These engines don't produce wing ripping power but they are smooth very well built and very light. I have some pics somewhere in my other computer I will try to find them. Keep in mind if you purchase these saws new they are kinda spendy. Have a great day!!!


POWER

ZAGNUT

My Feedback: (1)

thanks gord, i guess my "carbide" bits must be the el-cheapo type. i can get good bits for my small die-grinder so i'll try that.

power,way to go! your right about handstarting with the stock echo magneto but once you use battery ignition there's no going back. got any rpm numbers?

dave

BME

We use a Carbide bit in a bullet shape. Dont worry about the chrome plating. I have never chipped the chrome or had it peal. Nikosile is a different story. It will chip and peal. Then use a diamond ball to radius the inside edge of the ports. Use the timing specs I listed for best performance.


Keith
BME

bn120

My Feedback: (1)

Keith can you use the timing specs for any engine to improve the performance and what could you expect to gain in a lets say a 50cc engine on a stihl.

Darin

ZAGNUT

My Feedback: (1)

keith, what exactly do i cut on the piston crown? a step so the center extends into the combustion chamber? in the 23.6 parts diagram i see 2 different cylinder gaskets, one with normal looking transfer passages and the other with tiny little holes where the transfer should be, is this the difference in models you mentioned?

hey guys, keep in mind that chrome is bad for your health...

dave

BME

When cutting the piston you want to match the radius on the squish area of the combustion chamber. We do not cut the entire top of piston but mostly cut the outer edge. The piston ends up with a smaller radius or higher dome. You want all the compression you can get. I dont know the compression ratio but it runs fine on 87 octane gasoline. You can check the match fit from piston to head by turning and pushing the piston against the head. It will leave marks on the piston where it rubs and you will know where to cut the piston down at. As for the intake side(bottom skirt) we have cut the port on the cylinder on some and we have simply cut the piston skirt on the intake side only on others to obtain the 108 degree ABDC intake opening. These mods can be done on most any conversion engine if you intend on running it above 8000 rpm. If you want to run below 8000 rpm dont raise the exhaust port. Leave it at about 105 dgrees ATDC. I dont know about the different gaskets on the cylinder but I dont think you would want the ones with just holes in them. The good cylinders will have a transfer port opening that is the same size as the opening on the crankcase. Later models will have that opening smaller and it does not match the crankcase opening. I will see if I have time to do a conversion and take pictures for you guys.


Keith
BME

BME

I forgot to mention that the only difference between the 21cc echo and the 23.6cc echo is the piston and cylinder.


Keith
BME

Volfy

My Feedback: (23)

Keith, do you offer a conversion service as you described for customer's short blocks? Since BMEs are based on Echo engines, I've often wondered why you don't offer engines smaller than 44cc.

Again, I would like to thank you for taking the time to answer our questions and give us valuable conversion pointers. It certainly reflects very well on BME's behalf.

mikenlapaz

What is the converted weight with standard ign. system?

BME

The 23.6cc engine weighs 2lbs 2 ounces. Ignition weight is about 3.5 ounces. We used to offer this engine but with a battery powered ignition and the mods it gets pricy for a 23cc engine. We do have our own 30cc engine coming out soon in the xtreme series. Should weigh a tad over 1lb and blow the glow plugs off the satio and ys stuff. Its 100% propriatary and not like the glow engine conversions you see on the market. This engine was designed to be a gas engine from the start.


Keith
BME

mikenlapaz

is that the weight with flywheel and magneto as it would come out of a weedie? Or the weight with a RC ign and battery?

captinjohn

BME: Keith, are you going to give us a glimpse of this new engine very soon? Sounds fantastic!!!! Thanks Captijohn