Modding the Dolmar 420

[Fastcast]

Good work Brad...I'm really interested in seeing what kind of gains you can get.

:agree2: :agree2: :greenchainsaw:

Torque is something some never get to experience with other brands ..

 

[blsnelling]

The saw is ported and back together. I only fired it up for a minute before I had to go to something else. I'll get it in some wood later on today and get a new time on it. Initial response is that throttle response feels much better. That was the only thing not quite satisfactory stock. Not bad, but not stellar. A little more time on the engine may help that though.

 

[K9-Handler]

what is the number of the comparable makita saw? i can seem to see a dcs420 on their site. Thanks.

As far as I know, it doesn't exist yet. The Dolmar version only started appearing in dealers here at the end of '08. Probably hasn't trickled down to Makita yet.

 

[166]

Is the Makita DCS 4301 the same saw as the 420?http://translate.google.co.uk/trans...ta+dcs+4301&hl=en&rlz=1C1CHMA_en-GBGB312GB313

what is the number of the comparable makita saw? i can seem to see a dcs420 on their site. Thanks.

As far as I know, it doesn't exist yet. The Dolmar version only started appearing in dealers here at the end of '08. Probably hasn't trickled down to Makita yet.

Looks like the makita version is the DCS4301 for everybody across the ocean. The saw looks better in the Orange/Black combo much better

http://www.makita.co.jp/global/product/category/ope/dcs4301/dcs4301.html

 

[blsnelling]

Hey Steve. Does this cylinder have a chrome or NiSi coating? It is prone to slight chipping when porting. It was not a big deal but not something I like to see.

 

[scotclayshooter]

Looks like the makita version is the DCS4301 for everybody across the ocean. The saw looks better in the Orange/Black combo much better

http://www.makita.co.jp/global/product/category/ope/dcs4301/dcs4301.html

Nah Blue and grey all the way
My 7900 is a thing of beauty in blue and grey

 

[blsnelling]

I prefer the Dolmar colors myself.

 

[04ultra]

I prefer the Dolmar colors myself.

+1


Kinda the same reason I like Jreds better than Huskys .....

 

[blsnelling]

No disappointments here! It runs VERY nice. Throttle response is very good now. Cuts times are up 30-35% over stock and 25% over muffler modded only! This saw cuts its fastest times when you push on it, with all the compression and torque shinning through. That's not how I normally work a saw, but have included both normal and pushing cut times and percentages gained.

I did add another port to the muffler. The factory deflector would not give me the size opening I wanted. So I installed a Husky deflector. I also installed the screens on both ports since I have plenty of area now. I'm sure I have more then 150% but it idles and starts perfectly. Throttly response is much improved over stock.

Remember that I started with a saw without the catalytic converter. So if you have a bone stock saw with a cat, you'll likely see a lot more gains that what I've realized here.

The modding had no negative affects in the useability of this saw. Everything was a gain. There's no reason this saw shouldn't live a very long and happy life.

Tomorrow I will be making timed cuts with the different chains/bars/sprockets I have. That will include 3/8 lopro, .325 NK, and .325.

Stock

• Normal - 6.70 Seconds
• Pushing - 6.85 Seconds

Muffler Modded

• Normal - 6.40 Seconds / +4.5%
• Pushing - 5.95 Seconds / +13%

Ported

• Normal - 4.70 Seconds / +30%
• Pushing - 4.50 Seconds / +34%

Edit: I'm re-uploading the video and will post it on the next page.

 

[04ultra]

Nice Brad .......Looks like you did good ....





.

 

[K9-Handler]

Port

Any chance you took some pictures of the porting before you buttoned it back up?

 

[blsnelling]

No I didn't. It doesn't look any different than an of the others I've documented here. Just much smaller ports.

 

[gonecountry]

No I didn't. It doesn't look any different than an of the others I've documented here. Just much smaller ports.

Darn, I havent seen an intake port like this one and was really waiting to see what you did with it.

 

[166]

No disappointments here! It runs VERY nice. Throttle response is very good now. Cuts times are up 30-35% over stock and 25% over muffler modded only! This saw cuts its fastest times when you push on it, with all the compression and torque shinning through. That's not how I normally work a saw, but have included both normal and pushing cut times and percentages gained.

I did add another port to the muffler. The factory deflector would not give me the size opening I wanted. So I installed a Husky deflector. I also installed the screens on both ports since I have plenty of area now. I'm sure I have more then 150% but it idles and starts perfectly. Throttly response is much improved over stock.

Remember that I started with a saw without the catalytic converter. So if you have a bone stock saw with a cat, you'll likely see a lot more gains that what I've realized here.

The modding had no negative affects in the useability of this saw. Everything was a gain. There's no reason this saw shouldn't live a very long and happy life.

Tomorrow I will be making timed cuts with the different chains/bars/sprockets I have. That will include 3/8 lopro, .325 NK, and .325.

Stock

• Normal - 6.70 Seconds
• Pushing - 6.85 Seconds

Muffler Modded

• Normal - 6.40 Seconds / +4.5%
• Pushing - 5.95 Seconds / +13%

Ported

• Normal - 4.70 Seconds / +30%
• Pushing - 4.50 Seconds / +34%

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You may have to wait a few for the video to process on YouTube.

Youtube must be a Stihl fan

 

[blsnelling]

Youtube must be a Stihl fan

LOL. I re-uploaded it and here it is.

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[166]

Brad,

So did you find anything you did not like about the 420? It will be interesting to see what the bar & chain combo's do on this saw. 91VX vs 95VP vs 20LP.

 

[blsnelling]

Nothing in day to day use. The main thing I dislike is the limited coil, especially on a modded saw. I have no idea what this thing would turn. There's no way to tell. I did play with the tuning a little and seems to like to run rich and put its torque to work. As far as I'm concerned, a limited coil is a liablilty and more likely to cause problems than it will solve. I just don't get it.

As far as working on it, the top engine shroud is a major pain to remove. It has to come off to get to the coil or the cylinder. I would prefer to have a clamp on the intake boot rather than a press on fit. Ohh...and about 20 oz lighter, lol But seriously, this saw is in a different class than the Redmax 3800 and others I've tried. This saw is more in the league of the Husky 242. I think it will surprise you what it will run with.

This saw may really shine with a more aggressive chain. It cuts best with the 3/8 lopro when pushing on it. That tells me it needs more chain. The rakers are right at .025". You could try lowering them a little, but you might make it jumpy and ruin the chain. One of the .325 chains may be the answer. I hope to get those all tested tomorrow and report back.

 

[Javelin]

The 350/420's like the carlton n1c non safety chain real well! I have not used the oregon version of this chain in years but I would think it would be pretty accurate in saying the times will be close between the two brands of chain! I do know the N1C is faster than the factory safety oregon they come with so with the mods done it should be a very nice little hot rod for the money!

 

[cuttinscott]

Wait till it has a few more tanks of gas through it :rockn:




Scott

 

[blsnelling]

The chain testing is done and the results are surprising. No this testing is not in ideal wood nor is it totally scientific, but it definately answered the questions I was looking to answer. The tuning of the saw was not touch between chains and were all tested back to back. I'll list the chains and then make comments on eacy.

3/8 LoPro
Oregon 91VX
6 Pin Spur

• Equaled the best time of the test. at 3.85 seconds.
• Nice non-saftey chain.
• Cuts very well.
• Smooth in the cut.

Same as above only with 7-pin rim sprocket

• 4.00 seconds, 3.90 seconds pushing.
• Slightly slower cuts times with the 7-pin.
• Easier to stall the chain.
• Gives you the option of using a rim/drum.

.325 Narrow Kerf
Oregon 95VP
7-pin rim

• 4.75 seconds
• Slowest cut times by far.
• This was the only chain that wasn't new but had a fresh sharpening on it.
• With that said, I did not like this chain at all. It's very easy to stall in the cut. Not smooth at all.
• I don't think you can get .325 NK in a full chisel, but this semi-chisel just didn't do it for me or the saw.

Same as above with 8-pin rim

• 4.75 seconds.
• Equaled the times of above, but even easier to stall.
• A nogo here.

.325 Chisel
Oregon 20LP
7-pin rim

• 3.90 seconds.
• Very, very nice! Did I say it was very nice?!!!
• Best setup by far.
• Smooth as butter.
• Easy to control.
• Much heavier/more durable chain than 3/8 LoPro and just as fast.
• Gives you the option of running a rim/drum setup.
• Nothing to loose here. This is the best.

Same as above with 8-pin rim

• 4.0 seconds, 3.85 seconds pushing.
• Nearly identical cut times as above but much easier to stall.
• No advantage here.
• Still cuts WAY better than the .325 NK.

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