Fuel pump repair kit for Disston DO-101 chainsaw

[Lewis Brander]

I've been all over the internet looking for repair parts for my Disston chainsaw. One of the things I needed was to repair the fuel pump, for the gas oil mix was getting into the gearcase. I made a trip to our local NAPA store today and looked through a few small engine parts catalogs. I finally came across a fuel pump repair kit for a Kolher engine that looked like what was inside the pump on the Disston. I had the store order it and low and behold it fit like it was made for the Disston. I'll give you the NAPA part number, it's: 7-08051, so if you want, write this down for future reference. I plan to put some fuel into the old saw tomorrow and see if she'll fire up. Hasn't been rum since 1960. Wish me luck.

 

[McC]

Can't wait to hear if this solves the fuel in the gearcase problem.
Scott

 

[Lewis Brander]

Disston fuel pump kit.

I know the fuel oil mix, in the gearcase, was from the bad fuel pump diaphragm. Hopefully the old Stromberg fuel meter or carb is OK. There is a fan or some sort of blower in the carb. The seals there seem to be OK for now. I'll be happier than you know what if the old saw takes off. The old friend that gave me the saw has since died and every time I look at it, I''m reminded of him and the stories he could tell about his growing up out west in Kansas and Wyoming. I often told him he should have written a book about his life. Hey. if it takes off I'm sure everyone on this site will know. Thanks for the reply, Lewis.

 

[cbfarmall]

Sorry I couldn't help with the parts, but it's good to hear you found it at Napa. I felt bad when nobody was able to respond with assistance--old saws are getting hard to work on. Kohler working in a Disston is a surprise but I guess that means they made the carb. A Kohler float valve assembly is supposed to work in my International carb, though I haven't gotten around to trying. Got to get my 056 running...

Chris B.

 

[Lewis Brander]

Reply to cbfarmall

Don't feel bad about not being able to help on parts. AC Delco, napaonline, Mercury, and others I've emailed were of no help, either. Guess if you want parts bad enough you have to search and research for them by yourself. I've been banging my head off the wall trying to figure out where to get them and if I can find them I'm going to help others if I can. Hopefully someone may be able to help me in return. Haven't played with the saw as yet, but hope to get some time today and see what she'll do. I'll let everyone know what happens. Hopefully there is no fuel leaks, etc. to contend with, when I put fuel in the tank. Thanks for the reply. Getting a little excited on seeing what she will do. Lewis.

 

[Lewis Brander]

For your information.

Well I fueled her up and tried to get her started. Ended up draning the tank to repair some fuel leaks. Had to repair one of the gas lines and found that the fuel meter was also leaking. Removed it and found that the gasket under the side cover for the fuel impeller was shot. Replaced it with one from another carb. I then fueled her up again and tried to start it and found that the fuel and oil was squirting out the vent on the gearcase. Drained the fuel again, removed the carb and found the seal around the impeller shaft was leaking. Didn't know for sure what to do. There was a bit of end play in the shaft so I ended up putting 2 O rings on the drive end of the impeller shaft and 1 O ring between the impeller and the carb housing. The O rings push outward against the seal. Hopefully it will help stop the leak. The O rings were 1/16"thick by 1/4" inside diameter. Finally got her all back together tonight and wil try again tomorrow after I drain and refill the gearcase. Again, wish me luck, Lewis. As a friend told me, "Fun project." I just hope the gas doesn't affect the rubber parts inside the fuel meter. If I had some neoprene diaphragm materisl I might try to make new parts. Any idea where this might be obtained from? OK, it's late gotta go. To Scott Mueller, I'll let you know if this works.

 

[Lewis Brander]

The O rings worked on the old fuel meter

Well I don't know must have done something right. I'm not getting any fuel into the gearcase after installing the O rings I described. The saw still will not start. I found that I can get everything from a fine mist of fuel to large droplets of fuel through the spark plug hole while cranking over the saw. She has compression. fuel, a good hot spark and the timing is set to spec.Talk about Murphy's law. Gave the old saw quite a few pulls on the rewind today and the rewind spring broke. OH well. I repaired the rewind and am gomg to put up the saw for a while. Does anyone know of someone who has worked on the old fuel meters used on the Mercury engines. I have sent Mike Acres an email asking the same question. Seems like there might be someone who might have the information. OH well we'll see,looking for the initial high speed and low speed adjustments. OK, everyone. take care. Lewis.

 

[McC]

Wow, talk about a flashback. I went through everything you did right down to the rewind spring. That was the last straw for me. It is still sitting there with the rewind cable hanging out. I should try the fuel pump rebuild kit, and I couldn't find O-rings that were the same as the ones in it, did your new ones match the originals? I did get mine to run, but it was pumping fuel out of every hole it could find. It ran so rich, I had to hold it wide-open, and it still sprayed unburned fuel out of the exhaust. This is a very frustrating saw. I only work on it because it is probably one of the biggest one-man saws ever built, it drorfs any other saw I have except the big 2-mans. It does sound a lot like a boat motor when running. An old timer walked up behind me at our Baraboo show the year I had it running. I was pulling and pulling on it. He said "I told you those saws have demons in em". He had seen me there at a previous show and tried to warn me.

 

[Lewis Brander]

Reply to Scott Mueller

Scott. the impeller and shaft didn't have O rings on it. What I did was to add some O rings to the shaft. If you remove the 4 screws to the cover for the impeller and carefully remove it, so as to not ruin the gasket, you can remove the impellir and shaft. What I did was put 2 O rings on the shaft between the impeller and the cover so that the O rings pushed up against the original seal in the cover. I then assembled it and found that there was still some end play. I then took it apart and added an O ring on the long part of the impeller shaft. That O ring sits between the actual impeller and the brass bearing in the carb housing. When I put it back together there was no end play and it didn't turn ove as freely as before, but as it runs and the O rings wear a bit it will free up. The main idea was to put an O ring between the shaft and the seal housing so that the O ring would push up against the old seal and help stop the gas-oil mix from leaking into the gearcase. The impeller may have a little drag on it but will still turn or be driven from the gearcase. It seemed to work for me.
The saw I have should run. It's got good compression. spark and I know the timing is set OK. I have the timing garge for the saw. While cranking the saw over, with the plug out I can adjust the fuel so that it comes out the spark plug hole in a fine mist, to where you can see actual dropplets being sprayed out. But for some reason it doesn't seem to want to fire up. I drained the gas from the tank and put her up, after repairing the recoil spring, for the time being. Also removed the muffler and blew the fuel out of it. Makes me nervous to think if the saw ever started it might catch on fire, even though I keep a fire extinguisher next to me. OK, talk to you later. Lewis.

 

[Lewis Brander]

Old Disston stil has not Started.

Well, going to put up the old Disston for now, cranked on her enough. Have to get some other projects done before cold weather hits the north country. The old saw has all the right criteria to start but have not gotten a putt out of her. With the plug gap at .025" she has a good hot spark, but when I open it up a little to about .040" there's none. Thinking condencer. Will pull her apart later and check with an ohm meter. All I can say is its been a bit of a disappointment, was hoping to hear her run for the first time since 1960. Got some pictures off Mike Acres site of a Disston DO-101 guess I'll try to get some orange paint and pretty her up. The only bit of paint on this saw is on the handles so I'll try to match up the paint. If anyone has ever worked on or tuned up one of these Mercury fuel meters drop me an email, probably aren't too many people around anymore who have worked or tinkered with them. OK, talk to you guys later. I'll still be here. popping in from time to time, sandybaggen and seeing whats going on with eveyone else. Lewis.

 

[Lewis Brander]

Decided to more work on the saw.

Well, decided to do a little more work on the old Disston. I removed the handle and recoil start and pulled the blower fan and got into the bendix magneto. The mag seems to work, throws a good spark. Using an ohm meter I checked the condenser, It was shorting out or leaking to ground. So tomorrow I hope to pick up another and see if it will throw a better spark. Like I said she is getting fuel, has compression, but will not fire up. Will have to see if a new condencer solves the problem. Wil let you know what happens. Lewis.

 

[Lewis Brander]

Replaced the condencer.

I replaced the condencer and tried starting the saw. No luck as yet. As they say, " The saw has demons." The spark will not jump a 1/4" gap. The primary side of the coil has "0" ohms resistence and is not shorted to ground. The secondary side of the coil has 5.000 ohms of resistence and is not shorted to ground. Does anyone have any idea of what the resistence readings should be? If you know email them to me. I recieved an email from the chainsaw collestor and he says that the saw has to have at least 100 lbs compression to start. I'll have to check for sure to see what the compression is, but feel there's plenty of compression to start. I'm still open for suggestions. Thanks, Lewis.

 

[McC]

Lewis, I don't recall my 101 being difficult to pull, didn't have an excessive amount of compression. When you do get it running, be prepared for the heavy saw to try to throw out your back when it cuts through the log. It really pulls on your arms and back, wants to pull you to the ground unlike any modern saw. You just need to brace yourself. Here is a comparison of the big Disston to my Sachs Dolmar 114.
Scott

 

[Lewis Brander]

Scott. Thanks for the reply.

Scott. just want to thank you for the reply and information on how the saw will handle if I get it running. Also like the comparison picture of the two saws. I printed out some pictures from Mike Acres site of the Disston DO-101. The saw in the pictures were painted orange. Is the paint on your saw the original color scheme. Mine has what I thought was gray primer on the tank and recoil housing. After seeing your saw it got me to wondering about the paint on my saw. Maby my original color was a gray fuel tankand recoil housing with an orange handle. My saw looks identical to yours. If you would, let me know about the color scheme of your saw, Thanks again. Lewis.

 

[Lewis Brander]

Disston DO-101, compression test.

I received an email from the cscollector. He stated that I needed at least 100 lbs of compression, or the saw wouldn't start. I did a compression test of the old saw. Pulled the plug and screwed in my compression gage and cranked her over. The best I could get was 70 lbs. She has been sitting for a while so I pulled the gauge and added about a teaspoon of 30 w. oil. Redid the compression test and got 125 lbs. Released the pressure on the gauge and tried her a second time, got 115 lbs. Tried the third time and got around 105 lbs and the fourth time ended up with 90 lbs. Still feel that she should have enough compression to start. I've seen engines that didn't have hardly enough compression to kick back the flywheel when rotating the flywheel by hand. but they still started. Of course I'm talking 4 cycle engines, like an old cast iron block, Briggs and Stratten. Still looking for coil specefications. Wish I had another coil to try. If anyone has any suggestions, I'm all ears. Thanks for your emails and replies to my postings. Lewis.

 

[McC]

Hi Lewis, I'm not sure about the orange paint. I do have 4 of these saws. 3 are for parts, the good one is in the picture with the Dolmar. Part saw 1 is DO-100, serial # 284456. It is all orange with an orange handle. Part saw 2 is DO-101, serial # 606657. It is bare aluminum with orange handle. Part saw 3 is DO-101 serial # 633615. It is bare aluminum, handle is missing. Saw 4 is pictured. It is DO-101 serial 638627. There seems to be a coating on the aluminum, looks almost like a transparent tan color, maybe anodised? Who knows, it's 50 years old. If you need a coil, they are being reproduced for the Bendix scintilla ign. Check here for merc ign. parts. http://www.oldmercs.com/

 

[Lewis Brander]

Thanks for the reply

Thanks for the reply and link. Will check it out if the plug replacement doesn't work. Lewis.

 

[Lewis Brander]

Got the parts.

Got the new coil and condencer and installed them. All went OK, except I had to lengthen one of the leads. The magneto now will throw a 1/4" spark when you turn the flywheel by hand. Found that it would do that before I put the recoil back on. Will fuel her up tomorrow and she if the old saw will fire up. Will let you know what she does.

 

[Lewis Brander]

Well started a new thread. Lewis.

Well, mark this day on the calendar. The saw runs. Look under the new thread I started. " Hi, everyone, updates. Old Disston saw.

 

[Lewis Brander]

Fuel pump repair kit part number.

I hope that everyone who needed it got the NAPA part number for their Disston model DO-101 and D0-100. To list it again it's Napa part # 7-08051. This repair kit is for a Kolher fuel pump. It fits the fuel pump on the Disston saws like a glove. So be sure to write this down if you have any interest in or own the Disston saw. Take care, everyone, Lewis. Note: Just wanted to keep this thread going for a while longer so that anyone who wanted the part number would have a chance to get it.