Dolmar 64xx/73xx/79xx series, smurfs and solo 665/675/681 thread

[Lightning Performance]

You're late...

 

[PA Dan]

View attachment 297303

Wow Kenny should have known you would be a Shandy guy!

 

[huskyboy]

I’m happy with a bored out and worked over zama on my ported 7900. With some love the zama is a good carb on a worksaw. Most of the quirks are easy to fix. No need to buy a new carb for a ported 7900 if you or your porter knows how to work over the carbs. The hd12 is just an option for those who don’t know how to mod the carb (or don’t want to) and just want a plug/play carb that works I guess.

 

[Lightning Performance]

Wow Kenny should have known you would be a Shandy guy!

Here's the Kicker.
I walk up to the ladies that rent the house in front of my log yard in Tabernacle behind the old body shop last week about dark when they got home... any who, I offer the girls a bottle of this and they go no were good, we are drinking cans of it. They hold up these beers. I'm like cool... where can you buy it in cans?..., both of them, same time, Chatsworth. Then they made us some fresh bbq burgers wit fixins and we shot the chit. Very cool pair these two are. Both single, again. Not sure what's up between them if anything. So then I suggested next time they bring the beer and burgers. I just bring my usual and some shine. The chit that will come from their mouths will be priceless. Piney through and through, both of them. One has a black sportster and she's buying a new bike she said. They had me laughing my ass off. Good time wit MI beers
Maybe the PA and TN shine will be a truth serum this summer. Time will tell I think I'm a bad influence on myself
I missed the big memorial day party there. They said it was raining bad so they stayed in the house garage, on the covered raised patio and played beer pong. Nothing interesting or eventful happened, bummer.

This the best read in whole thread here. I'll update after the next shindig. Have to get the next party date this week sometime and pics. Pics for the cavemen and nay sayers and Dan
I take pics freely lol

 

[PA Dan]

I’m happy with a bored out and worked over zama on my ported 7900. With some love the zama is a good carb on a worksaw. Most of the quirks are easy to fix. No need to buy a new carb for a ported 7900 if you or your porter knows how to work over the carbs. The hd12 is just an option for those who don’t know how to mod the carbs who just want a plug and play carb that works I guess.

Or for someone that fuggs up their Zama a week before the buildoff...I guess!

 

[Lightning Performance]

I’m happy with a bored out and worked over zama on my ported 7900. With some love the zama is a good carb on a worksaw. Most of the quirks are easy to fix. No need to buy a new carb for a ported 7900 if you or your porter knows how to work over the carbs.

No new nuffin.
Drill till you can't and start over
These carbs are from the junk pile but look great. Next time all the welch plugs get drilled or come out. Might just be smutch in there or black death gumball.

I might take the good running 6401 and pop that carb on the 8401 and see if it runs right. If it does I can mill with it then finish the port work all seated up nicely. The piston is junk so that needs an update for sure. 7910 might out run it. Time will tell.

 

[huskihl]

I’m happy with a bored out and worked over zama on my ported 7900. With some love the zama is a good carb on a worksaw. Most of the quirks are easy to fix. No need to buy a new carb for a ported 7900 if you or your porter knows how to work over the carbs. The hd12 is just an option for those who don’t know how to mod the carb (or don’t want to) and just want a plug/play carb that works I guess.

No need to work over the carb if he knows how to port the saw

 

[huskyboy]

No need to work over the carb if he knows how to port the saw

You saw a loss in hp with a bored out carb?

 

[Lightning Performance]

No need to work over the carb if he knows how to port the saw

Agreed
I hate changing carbs. It so so so much easier to just smooth out both ends and reduce the throttle and choke shafts.

 

[Lightning Performance]

You saw a loss in hp with a bored out carb?

He is trying to tell you that proper case and intake timing negates the need to dick with the carb on 90% of the saws ever made. It's just a fact not really news. Kevin learns in months what takes others sometimes years to grasp. It see his point most times.

 

[huskihl]

You saw a loss in hp with a bored out carb?

Didn’t say that. I just thin the shafts

 

[huskyboy]

Didn’t say that. I just thin the shafts

I swapped carbs back and forth with sondre’s 7310 with the one on my 7900 just to see if it liked it. Seemed to work good. Bout 5 % or so gain in wood on a already strong unit. Seems like drilling isn’t always necessity with all the variables in porting and elevation. Especially with the smaller 73 which doesn’t eat as much gas as a 79. Restriction seems to just be the venturi size which makes sense since it’s rather small for a 80cc saw. Thinning shafts alone makes a difference since it kinda does the same thing.

 

[huskihl]

I swapped carbs back and forth with sondre’s 7310 with the one on my 7900 just to see if it liked it. Seemed to work good. Bout 5 % or so gain in wood on a already strong unit. Seems like drilling isn’t always necessity with all the variables in porting and elevation. Especially with the smaller 73 which doesn’t eat as much gas as a 79. Restriction seems to just be the venturi size which makes sense since it’s rather small for a 80cc saw. Thinning shafts alone makes a difference since it kinda does the same thing.

Usually lose some dawg-ability with the bigger carb though. It’ll cut faster straight down, sure.

 

[huskyboy]

Usually lose some dawg-ability with the bigger carb though. It’ll cut faster straight down, sure.

Be interesting to see at what point the venturi size would cause a torque loss. Probably a tipping point somewhere? Good for a dyno test, it wouldn’t lie.

 

[huskihl]

Be interesting to see at what point the venturi size would cause a torque loss. Probably a tipping point somewhere? Good for a dyno test, it wouldn’t lie.

It’s not really a torque loss, though that’s what we all call it. The torque goes up with the horsepower. But the curve is probably narrower. It’s just less forgiving.

 

[huskyboy]

It’s not really a torque loss, though that’s what we all call it. The torque goes up with the horsepower. But the curve is probably narrower. It’s just less forgiving.

Cool, makes sense. I guess we could see that curve change on the dyno sheet? Give some idea of what you felt in the wood and eliminate the variables.

 

[Lightning Performance]

Usually lose some dawg-ability with the bigger carb though. It’ll cut faster straight down, sure.

On outboard motors you give away the dog and the pink slip.

This is where your going Mason but with water.
Your hole shot is gone gone. You need another prop loaded down. 140 4V comes with 1 3/8" bores then down to 1 1/4" on the 135 or something close to that. 135 will pull a hell of a hole shot with 1 1/8" 125 carbs like neck braking. All using the same prop like a 21 14 3 or 4 blade cleaver and no other adjustments. The carb is more set to the stroke than bore imo. All out racing is racing. We race, cruise or run fast. So we mostly run the standard 1 1/8" with a choke. The ported extra set of gutted big carbs added nothing to the top end. We are running a non ported stock block. The rest is warmed over like a ported saw. We pull right to 7500 with a prop swap so power is not an issue. The rpm will climb but not your speed @ wot. We do run wide open exhaust.

With no other changes we seeing a difference of 5-7 mph on the top end. We average 72 mph in that boat now with 1 1/8". One guy empty 78 best runs one way on big carbs. Fuel use is about the same over a day. Cruising speeds don't change. Water is easier to test on than cutting wood. Plus we can make a return trip to get better averages during testing. Would I run the biggest carb daily, hell no! We run chokes and stock carbs mostly. Other better ways to search for power.

 

[Lightning Performance]

It’s not really a torque loss, though that’s what we all call it. The torque goes up with the horsepower. But the curve is probably narrower. It’s just less forgiving.

Zackly

 

[RI Chevy]

Wow Kenneth. Bouncing all over the place tonight I see. I thought this was a Dolmar saw thread.

 

[Sagebrush33]

Wow Kenneth. Bouncing all over the place tonight I see. I thought this was a Dolmar saw thread.

Kenny's been drinking since like 5pm.