The Dolmar 7910 - Snellerized Style

[VinceGU05]

She's done, and lookin' mean!

Sure beats what I started with!

while it looks great i would prefer to see it carbon fibre style. personal choice. hey brad, water ya grass; its drying out

 

[blsnelling]

hey brad, water ya grass; its drying out

I know

 

[Poleman]

Can't blame Brad....look at the heat the saws putting out!!!!!!

Besides, its fall time to cut wood and end yard work....

 

[benp]

He did not. The saw has perfect manners as is. I'm hesitant to mess with it. Idle is perfect. Throttle response is instant. Tuning is easy.

That's how mine are.

But.....there's that little voice rattling around questioning how much better a modded carb would be.

 

[Terry Syd]

Hopefully Brad will give us his time to really test the difference. If he doesn't have big enough wood, then maybe an 8-pin might substitute for an extra load.

Rich has noticed a difference between the jetting on stock and ported saws. I expect that is because the torque peak has been raised on the ported saw and the low speed circuit has a bigger gap to fill before peak torque. Rich has bridged the gap with a bit more low speed flow.

A carb swap is an easy mod for most guys. Do a muffler mod and then a carb swap and most of the EPA issues have been eliminated.

There is still the issue of excess hydrocarbon emissions that Blair refers to in his work. The factories are running around 2 degrees less blowdown to help control them. Not a biggie for most wood cutters, but a port job and extra compression (nitrogen oxides emissions) changes the picture on performance for the enthusiast.

I'm looking forward to the comparison of the stock EPA carb to the modded carb. - Brad, put some freaking load on the saw and make the saw WORK.

 

[blsnelling]

I finally get to go cut some wood again, back up at our church camp. I'll be putting this new 7910 to work and getting some videos tomorrow. I'm looking forward to getting back out to work the saws a bit. I'm going to have some time to play with the modded carbs a bit as well.

Here are a couple of the trees already down.

 

[SCHallenger]

That church camp has been a great "test track" for you. I'm looking forward to the vids!

 

[Locust Cutter]

Hell if I was closer, I'd love to come play. That ought to be some fun.

 

[blsnelling]

Well, I'm pretty bummed. I got a call from the camp care taker, and several guys showed up today and already got it all done Instead, I'm going to venture over near Indianapolis to drop a tree for my cousin's church that they've been on me to do for several months now. At least I still get to run this saw

 

[SquareFile]

Now who in there right mind wound have a saw hydro dipped.

 

[porsche965]

Now who in there right mind wound have a saw hydro dipped.

Me. lol

 

[fordf150]

Me. lol

I would do it to. That saw may end up with somewhat of a twin. I like the muffler and spikes. Really like the hood. Will have me a saw like that one day

 

[Poleman]

Me three......that saw is HOT!!!! LOL

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[CR888]

l think Brad will like the modded carb, little gains here and there all add up to make the best saws. Very nice looking saw! l am looking forward to hear from Brad about the carb's performance. l think he should run the unmodified carb for a few tanks first to really notice the differences.

 

[Terry Syd]

Or maybe the other way around - run the modded carb to get used to having the torque on tap and developing a cutting technique with the saw that can make use of the torque - then swapping to the stock carb and noticing how 'weak' the stock carb is and having to change techniques to compensate.

Either way, it will be interesting to get his unbiased impressions as this will be his introduction to using a modded carb on a work saw (as pretty as it may be).

 

[CR888]

l really want to do these carb mods to my 681solo, it has a walbro carb. l think it would be good for a 6400 l have too. l got the pin vise and micro drill set.....then chickened out!lol l think before l operate on my oem carbs some pratice on a cheap china am carb may be best. These exact modds are well described in Graham Bell's performance tuning and he sugests exactly what you guys are doing in the same way. Theres a few good diagram pics explaining things well.

 

[Terry Syd]

These diaphragm carbs are a separate breed to something like a Mikuni for a bike. The same relative fuel flow concepts apply, but the carb configurations/circuits are completely different and more difficult to get your head around.

The cheap Chinese carbs are a good way to 'make some mistakes' and not blow out the budget.

The Walbros require a different approach to the Zama 'twin jets'. If you get a kit of a selection of Walbro springs you'll probably find it much easier to dial in the carb. You may not even have to drill the transition holes, just tweak the low speed needle to where you want it and then find a spring to clean up the idle and transition. If you can't fix it with the spring, then drill and go back to the springs, repeat if necessary.

 

[blsnelling]

I'm sorry to disappoint, but no video. All of my work saws were setup to work with yesterday. What I had left was a 32" Tsumura L&T, and it was way too long and nose heavy for the 7910. The chain I had on it was horrible. Rather than misrepresent the saw, I'll wait until I have the chance to set it up properly.

 

[Four Paws]

What I had left was a 32" Tsumura L&T, and it was way too long and nose heavy for the 7910.

Imagine if you had a regular weight bar! Does the 461 balance better with a 32?

The chain I had on it was horrible.

Why was it horrible...was it Stihl chain? Or, filed by a cull?

 

[SCHallenger]