Stihl MS660 carburetor

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husker67ne

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I'm being told that my saw won't run because the new carburetor that I installed is for high altitudes and the carburetor I need costs $116. I live in Florida at about 40 feet above sea level. Is there any basis to this? If a car mechanic told me this I would throw the BS flag but I'm not familiar with small engines. Thoughts?
 
I do know that vehicles in high altitudes can be tuned different for the thinner air. I had a room mate that used to race Super Stock, and they had a tray of jets for every elevation of every track on the east coast, plus weather conditions. So, it can make a difference. I don't know if they actually make different carbs for high altitudes, Joe.
 
In the 064/066 manual it talks about managing changes in altitude by changing the main jet on the 064, but the 066 is just retuned using the H /L screws.

In the 650/660 manual these are both catered for by retuning - and its only a very slight amount

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Thanks for the info. One problem is that we can't even get the saw to start to make those adjustments. Guess I'm stuck paying for the repair.
 
The shop is full of crap. Your saw will still run even if it is tuned for a higher altitude. It may run only slightly off of ideally but it will still run. If you are using this saw for milling then you really need to learn to tune the saw rich unlike what the guys at the shop will do unless you specifically tell them to and even then they may not know how. That is why they are steering you to a new carburetor in the first place. They don't know that the high altitude carb and the low altitude carb are one and the same and they also don't know how to tune said carb. They will just use the factory settings the carb comes with. They wont even touch the mixture screws.

Try doing some simple diagnostics first. Saws wont start or run for a ton of reasons. Most are carb/fuel related. If you can give the saw a compression test, remove and clean out the carburetor, check for spark, and clean out or replace the fuel line then you can go a long way toward fixing it yourself.

Chainsaw milling is a game where dealers and shops need not apply. Warranties and EPA regulations go right out the window otherwise your saw will be toast. You either need someone else you really trust or you go it yourself when it comes to chainsaw modifications and tuning to idealize your saw to milling.
 
Well, I think before I pulled the muffler, I'd pull the plug and crank it over and see if it has spark. Even a week spark will usually run. If it has spark, put a little shot of fuel mix in the carb and crank it over and see if it fires. If still no fire, i'd pull the muffler and see what the inards look like. Plus, you really need to move over to the chainsaw forum, they would have had it running by now, Joe.
 
Well, now that I reread you initial statement, did the saw run before you put the new carb on? If it just ran, but poorly, and now it doesn't run at all, I would point to the new carb, Joe.
 
Yeah, I wish I had found this site before going to the shop with the saw. Thanks for all the advise guys. It is back home ready to go to work with a new carburetor and I'm out a couple hundred bucks. All part of the grand plan.
 
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