670 project (pics)

[Steveo_supremo]

Wow, Jerry I just learned a little bit about My town. Ive lived here for 13 years and I drive by Big Bertha all the time, but I've never stopped and read the writeup. Funny thing is used to work for Mo Takhar at his reman mill.

No real progress has been made on the saw today. I did fool around with the 2 carbs, trying to swap the shafts and linkages from the 670 carb to the 272 carb. I ran into a bit of a snag with the choke that will require some creative engineering. No pics of that, though.

My 5mm time-sert kit that I ordered from Wurth showed up today. I'm going to use it to repair a stripped top cover bolt hole tonight. I'll post up some pics of that later.

 

[pioneerguy600]

Wow, Jerry I just learned a little bit about My town. Ive lived here for 13 years and I drive by Big Bertha all the time, but I've never stopped and read the writeup. Funny thing is used to work for Mo Takhar at his reman mill.

No real progress has been made on the saw today. I did fool around with the 2 carbs, trying to swap the shafts and linkages from the 670 carb to the 272 carb. I ran into a bit of a snag with the choke that will require some creative engineering. No pics of that, though.

My 5mm time-sert kit that I ordered from Wurth showed up today. I'm going to use it to repair a stripped top cover bolt hole tonight. I'll post up some pics of that later.

It takes someone from outside to find the most interesting tid bits about your home territory, fresh eyes and an inqusitiveness about history has served me up a lifetime of facts and stories that would fill several books the size of a family bible.
Your choke opens from the opposite direction?

Pioneerguy600

 

[Steveo_supremo]

Your choke opens from the opposite direction?

Yep. Got any suggestions?

 

[pioneerguy600]

Yep. Got any suggestions?

It has been a couple of years since I built mine, I remember finding a carb from a 266 I think, I changed all my shafts, choke plate, butterfly plate and linkages over to it. Do you have a Tillotson on yours?
Pioneerguy600

 

[Steveo_supremo]

A Til-lot-son it is. The 670 carb is a HS230 and the 272 carb that I will be running is a HS260.

 

[pioneerguy600]

A Til-lot-son it is. The 670 carb is a HS230 and the 272 carb that I will be running is a HS260.

You need to find a carb from a saw that runs a separate impulse line but has your type of choke linkage. I may have used a carb from a Echo 670 as I had a couple of them around that time. If I was to do that swap again I would just add the external elbow to the 670 carb, not a hard job at all.
Pioneerguy600

 

[Cantdog]

Hi Steveo...This may or may not be helpful to you depending which way you choose to go. On the 61/268XP in my sig I am running a 250A carb from a 670. I really like the Jonsered choke/high idle setup as opposed to the trigger lock Husky rig. The 250A is a recirculating carb so I had to bore the case and the tank for the return line. Then there is the top loading impulse setup as opposed to the through the manifold and carb body inpulse. I set the manifold up in the drillpress and bored the correct sized hole to intersect with the impulse corridor and accept a right angle fuel inlet nipple from another tilly carb. These nipples are not theaded but are an intereference fit with a very slight taper so hole size is all important. Anyway I didn't use any sealer just tapped into place with a tiny ball peen. This has worked great with not the slightest problem. One word of caution should you do this...position the impulse pickup closer to the carb rather than the cyl. If you're to close to the cyl it will interfer with the partition wall in the top cover. The 250A is basically the exact same carb as the 260, same bore size etc. The only difference is the choke linkage, the impulse corridor and it's a recirc carb. THe only other problem I had was since this was a 61 Husky I didn't have the correct choke pull for the Jonsered choke (ie; the husky one goes in and is bent down to connect and the Jonsered goes in and bent up) it didn't seem like there was any way except finding a Jonsered pull. But after close inspection I saw you could flip the husky choke pull over and reattach from the opposite side of the linkage plate and it would work perfect!! I did have to trim out a tiny corner of the outside choke pull to fit around the small bolt that mounts the back of the intake elbow on the 670, so the choke would go in all the way. It all works very well with no problem what so ever. Oh the only other thing was the choke symbol is now on the bottom of the pull LOL!! Interesting.....will look forward to how you work around this issue using the 272 cyl with Jred linkages etc. as I am coming right along behind with the same setup. I do have both the 250A and 260 carbs to work with so I'll watch closely to see what you come up with!! I'm leaning towards doing the same thing again because it's easier than it sounds and seems to work flawlessly and with 670 I won't have the choke linkage issue. Again the carbs are the same bore and flow rates so there is no performance advantage of the 260 over the 250A.

 

[Steveo_supremo]

Jerry and Cantdog thanks for the tips. I will be pondering them as I am snowmobiling in the mountains today.

 

[pioneerguy600]

Jerry and Cantdog thanks for the tips. I will be pondering them as I am snowmobiling in the mountains today.

Thanks for the Picts Steve, beautiful country out that way and you got snow. Ground has been bare here up until today, getting a dusting out today.

Pioneerguy600

 

[Cantdog]

That is just stunningly beautiful country and the snow looks crazy deep from coverings on the trees.

Jerry we had snow on the ground since the first of Dec. Nothing like that though!!!

What you're getting came through here yesterday....not alot but it really snowed hard right around dusk just as I was out doing the horses....... figures.....:bang:

 

[pioneerguy600]

That is just stunningly beautiful country and the snow looks crazy deep from coverings on the trees.

Jerry we had snow on the ground since the first of Dec. Nothing like that though!!!

What you're getting came through here yesterday....not alot but it really snowed hard right around dusk just as I was out doing the horses....... figures.....:bang:

No outside chainsaw work here today, snow is really coming down and the wind is kicking up, got around 5-6 inches down now and its starting to drift some. After lunch I will go out to the shop and put the 460 back together, hope I got all the air leaks stopped. Waiting on parts for the P62 and the 266SE. but can choose from the heap the next one to start.
Pioneerguy600

 

[Steveo_supremo]

OK so I repaired the wallered-out top cover screw hole using a Time Sert. Here's the pics:

Stripped hole in case:

M5 x .8 Time Sert kit:

Drilled, tapped and countersunk:

Insert on driver tool ready to install:

Insert installed, beter than new:

 

[Cantdog]

That looks like a sweet rig....where do you get those?? Look way better than a heli-coil. Nice all steel threaded insert....way excellent.....so did I ask where do you get those????LOLOL!!!

 

[Steveo_supremo]

Here in Canada, they are distributed by Wurth. We have a Wurth Rep that comes around the automotive dealership where I work so I ordered the kit through him. Cost about a hundred bucks for the kit and the inserts are about a buck each. I think You can get them from a number of sources in the US. I know Madsens sells them and there were also quite a few on ebay last time I looked. They are also somewhat cheaper in the US I think.

I wish my pics of the repair were a bit better. A photographer I'm not.

 

[Cantdog]

Thanks for the info I'll look into it. Your pics look good to me!!

 

[little possum]

Pretty sure I stuck the carb off the 272 on my 670. Choke worked as well.
It should be getting the new 13" roller nose bar and chain put on this week for the upcoming GTG. Maybe a mild muffler mod to get it by, till it gets ported.

I can check the numbers if need be.

Oh, PS, subscribing!

 

[Steveo_supremo]

Pretty sure I stuck the carb off the 272 on my 670. Choke worked as well.

You must not have a throttle lock (or high idle), though.

I've decided I'm gonna run a 670 carb, I'll just have to drill out the impulse passage and use the pump cover from the 272 carb. I have read that the 272 carb has a bigger venturi but I have carbs from 670 and a 272 sitting side by each on my bench and I can't measure any difference.

 

[little possum]

No throttle lock. I can remember that much.

 

[parrisw]

Nice project!! I'm here if ya need some taken off that cylinder base. What's the bore size?

 

[Cantdog]

You must not have a throttle lock (or high idle), though.

I've decided I'm gonna run a 670 carb, I'll just have to drill out the impulse passage and use the pump cover from the 272 carb. I have read that the 272 carb has a bigger venturi but I have carbs from 670 and a 272 sitting side by each on my bench and I can't measure any difference.

Yeah, I thought of drilling out the passage too as the lineup hole is already there but decided that, at the time I had 3 isolation blocks and only one carb, so I went with external impulse. In case I didn't get it right the first time, I would have 2 more chances!!! Also I was in a hurry to get the saw together in time to get to a GTG. It would surely make a more "foolproof" setup keeping the internal line, I would think.

I don't think there is any difference in the bore sizes betwen these carbs and also the 224 from the 266XP. I believe they are all the same size venturi.