Author Topic: modifications (Read 933 times)

gary courtney · « **on:** January 16, 2014, 08:01:10 AM »

All of us likes hopped up cars,motor cycles etc. my discussion ponders a friend of mine owns a diesel business and he says cummins diesels are bullet proof until he sees mods-upgrades then every thing else associated with engine goes downhill like a roller coaster! how about chainsaws ie. bearings,seals etc. discuss!

NCFarmboy · « **Reply #1 on:** January 16, 2014, 09:11:21 AM »

Muffler mod is cheapest upgrade like putting headers on car/truck. Usually gives 10% or more power. Engine runs cooler always a positive.
Shep

ZeroJunk · « **Reply #2 on:** January 16, 2014, 09:22:44 AM »

There are port jobs and there are port jobs. The mild porting done on work saws has little if any negative effect. Now, if you are building something to race there is going to be more stress and shorter life.

sharkey · « **Reply #3 on:** January 16, 2014, 10:13:27 AM »

If you open up the muffler, you will need to re-tune the carb adding a little more fuel.

HolmenTree · « **Reply #4 on:** January 16, 2014, 11:26:59 AM »

Quote from: gary courtney on January 16, 2014, 08:01:10 AM

All of us likes hopped up cars,motor cycles etc. my discussion ponders a friend of mine owns a diesel business and he says cummins diesels are bullet proof until he sees mods-upgrades then every thing else associated with engine goes downhill like a roller coaster! how about chainsaws ie. bearings,seals etc. discuss!

When a operator gets his saw modified whether its woods or race modified, the stock bearings and other internal parts are going to be even more short lived if its not run properly.
Warming up the saw to WOT will need to take longer and slower. Even when fully warmed up blipping the throttle up and down to WOT quickly will need to stop.
Its OK to blip the throttle to WOT as fast as you want, but you have to "let off" the throttle slowly.
Rapid blipping up and down to WOT is extremely destructive especially to the connecting rod's wrist pin bearing.

Andyshine77 · « **Reply #5 on:** January 16, 2014, 04:59:43 PM »

In a normal work saw, If you keep compression reasonable and keep the rpm's down, the bottom end will be fine. In hotter ported saws, everything takes more stress. Some saws have stronger bottom ends than others, so that needs to be taken into consideration when porting a particular saw. Running more oil helps a lot as well, and has almost eliminated bottom end issues with saws like the 372 and 385/390. Bliping the throttle constantly is never a good idea, but neither is feathering the throttle, as it can create lean conditions. The carbs on chainsaws work at two speeds, idle and full throttle, nothing in between. Keeping your chain not only sharp, but smooth is also a good idea. A jittery chain can destroy a saws bearings in no time.

Keep in mind chainsaws are for the most part, overbuilt for the power they produce.

HolmenTree · « **Reply #6 on:** January 16, 2014, 05:20:37 PM »

Andre, that's good advice.
Another thing speaking of bottomend problems is never run a saw out of gas right to the very last drop by choking the carb. As soon as it sputters shut it down and refuel.
I've seen a lot of connecting rod bearings taken out by this repeated habit some loggers have done.

Andyshine77 · « **Reply #7 on:** January 16, 2014, 05:27:20 PM »

Quote from: HolmenTree on January 16, 2014, 05:20:37 PM

Andre, that's good advice.
Another thing speaking of bottomend problems is never run a saw out of gas right to the very last drop by choking the carb. As soon as it sputters shut it down and refuel.
I've seen a lot of connecting rod bearings taken out by this repeated habit some loggers have done.

You sir are 100% correct. It's best not to even get to the point the saw sputters, by that time the saw was likely running a bit lean for a minute or so.

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