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RodStayner

Sunstar problems

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RodStayner
It looks like I have a couple problems on the old 1988 16HP Sunstar. Problem #1: Tonight while my wife was mowing while I was giving the kids their baths (doesn't sound right, does it?), she said it started smoking and running bad. I went out, and saw that the engine was HOT! I checked the oil level and it appeared low (hard to tell since it was getting dark). I pulled the air filter and it was pretty dirty, especially the outside foam. I started it up and ran it up to the garage (ran okay) and cleaned everything up. It appears that it overheated for some reason....I thought I remembered some old posts in the old site about this problem. The engine is pretty clean, and I see no debris under the shrouds. Problem #2:Another thing that has plagued me this year is when I speed up the throttle from minimum to midrange sometimes it sputters and I have to pull the choke out a little to keep it running (doesn't matter if it is cold or not). A couple of times this year it was running a long and just sputtered and died for no reason. It runs fine at full throttle. It didn't do this last year though. Any thoughts on these issues? Rod

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Al
Rod, A couple of things come to mind. 1 If the carb is dirty, a lean mixture will cause it to run hot. Check the fins on the transmission cooler, if it is plugged that is the source of cooling air for the engine on this unit. Since I believe this has a 16 Kohler M16, it should have a hard steel key in the flywheel and it is not likely sheared or partially so, the timing should be good. Down the road if nothing else shows up, it might be worth checking because late tiiming makes them run VERY HOT. Most likely a restricted jet in the carb, with the choking needed. Also check the fins around the cylinder particularly on the flywheel side. We have a trashed COOKED V twin Vangard in the shop right now [broken rod, oil like 90 weight trans lube] and I may post a picture of the mess in it. Looked OK from what you could see from the outside. Completely plugged on the flywheel side of the fins, and no those acorns and hickory nuts won't go through the fins. We see this restricted fin problem all the time. If the oil level is low the temperature goes up also. Much of the engine heat is dissipated through the oil. A restricted muffler will also cause an engine to run Very Hot. Sometimes a mouse will carry junk up the pipe, sometimes a baffle will come loose. Overheating will cause excessive oil consumption, and you may get low on oil quickly with out even realizing it. Do not use multi grade oil in the flat head engines. Use SAE 30 Multigrades break down in the area of the cylinder near the exhaust valve, they can't stand these high temperatures. All of the engine manufacturers call out SAE 30 [Summer]for the flat head engines. As for the hesitation there should should be some tiny holes [transition passages] near the edge fo the throttle plate in the carburetor. One of these may be plugged. If your engine has a fixed main jet and I suspect it will, they are jetted plenty lean when new and any dirt or water just aggravates the situation. Good luck, Al Eden

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a7117puller
yup, the transmission cooler, and that tractor is notoious for catching fire, mostly due to the tranny cooler. keep up on the maintenece!

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RodStayner
Just an update: I removed the shrouds on the Kohler--nothing clogged up. I replaced the air filter and changed the oil with fresh SAE 30; I couldn't find anything at all wrong. I finished mowing about 1 acre with no problems, not even a hesitation with the throttle that I have sometimes experienced. The engine didn't seem any hotter than normal when I was done. I did order a new bulkhead seal as mine came apart recently. This tractor only has 320 hours on it, so I hope it keeps on going! Thanks for the responses! Rod

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RodStayner
Possible solution I just thought of: Maybe I should just keep the wife off the tractor? She likes to mow as fast as the tractor can go! If she keeps that up on our hill I'll need to give her a helmet and install a rollcage on the Sunstar! She couldn't do that with the Crapsman tractor I sold this spring. It would just push the grass over instead of cutting it, and that was at a slow speed!!! Rod S.

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Al
Rod, Maybe she appreciates it"s capabilities more than you do. Sounds like she mows like I do, As fast as I can without pulling out tooooo many roots. Have a good one,, Al Eden

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HubbardRA
I take the opposite approact that Al does. I live in a subdivision and only mow about 1/3 acre. I have an AC 716 with a 48 inch mower. I can take it very easy on that machine and still get done quickly. My wife still can't figure out why I need the four tractors that I have, for our small place. She can't understand that I plan to retire in a few years, and want to get things ready while I have some money. When I quit work I plan to quit living in a subdivision. The tractors should be right by that time. Rod H.

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WISCONMAN
Rod: I have a 20 HP sunstar and from day one it ran lean. (and hot). The carb on my tractor was of the fixed main jet type. I got a carb off of a big K series twin which has an adjustable main jet. What a difference- no-more keeping the choke half on while the engine warms up.

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Al
Hi, I agree on some of these fixed jets. In the 80s, we replaced a few of these with adj jets and warrantied them in about 4 cases. The fixed jets were brought on line mainly because of the degradation on gas in the 80's. During this period vapor lock became a hair pulling nightmare. The problem arose because little air bubbles would collect between the adjustable needle and the jet it was in. As these bubbles would collect they would restrict the flow of fuel through the jet. More bubbles would collect [like soap bubbles in a sink] and eventually on a hot day the engine would die. Let it set 15 minutes, it would cool, the bubbles would break and it would start and run fine. By going to a fixed jet the diameter was greater than the doughnut shaped jet area that existed with the jet and needle. This allowed the bubbles to go through the jet without "sticking". Greatly reducing the vapor lock problem. The carbs were jetted pretty lean due to the early minor issues with the EPA. The trend continued and after a couple of years all of the having to build carb heat shields etc because of fuel boiling and vapor lock, kind of faded due to reformulation of gasoline. Now due to mcuh stricter EPa regulations fixed jets will continue to be a part of the landscape. Any of the carbs that have adjustable jets, mostly chain saws and trimmers have 'Restrictor caps" on the them, must have them on. Any shop that lets a carb go out with the caps removed can be fined 10,000.00. In the future look for Fuel Injection to be BIG on the scene in the near future. The data I have seen on the new 26 hp Kohler Fuel Injected engine, the fuel consumption is reduced by over 50% over the 25 hp. The same engine except carbureted Commercial cutters can pay for the FI system [700.00] in the first year with fuel savings. From what I am hearing from manufacturers, Like calculators and cell phones these systems will get cheaper and simpler in the future. By the time the super tough 2005 EPA regulations must be met, I expect to see FI even on push mowers My 2 cents worth and its free. Value accordingly. Good luck, Al Eden

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gretsch
Al, When you say commercial cutters can pay for the fuel injection ($700) in one year with gas savings, does this mean that older engines will be able to be converted to fuel injection and that the expected cost is about $700? Will it use a CPU like autos? Why have they (the manufacturers) waited so long to begin converting over to fuel injection? It has been around more than 20 years in the mainstream auto segment.

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Al
Hi, The Kohlers use a version of the Bosch automotive system. There are 2 reasons why the systems are this long coming. 1: Cost, not many customers are willing to pay 700.00 extra. After 20 years of automotive use the volume and improvements have finally gotten the cost down to this level and much better performing systems . Presently the interest is mostly in the Commercial users. Everybody wants something cheap. That’s why they sell so many MTDs About 2 years ago in a Briggs service school we were told that IF there were no major technical breakthroughs OR if the EPA didn’t back off on their requirements down the road WE MIGHT see push mower engines with computer controlled, fuel injection, valves and ignition. [Catalytic converters are almost a certainty within a year or two.] Probably, at a cost of around $1000.00. This would devastate the push mower market. The commercial cutting business would boom. In an industry where Mc Culloch 2 years ago could not build product that they could sell in USA because of emissions, filed bankruptcy and was liquidated in a 4 day sale. A Chinese company bought the name and will likely re-label various items, Garden Way [Bolens, Troy Built, and several companies] filed bankruptcy and was liquidated. MTD bought the Troy Built portion. John Deere bought Homelite a few years ago and sold it to a Chinese company this year. After losing 92 million dollars on Homelite. Snapper is begging someone to buy them, as they need someone to invest 61 million, or they will be bankrupt in 6 months. This industry is not able to take giant leaps in technology across the board in consumer products. Down the road as technology and volume reduces the cost it will phase in. Right now the market isn’t there. A giant industry [like automotive] is able to make great technological and cost reduction breakthroughs better than any other 2: Service. Dealers need to purchase the equipment and be trained to service them. Presently the equipment may cost up to 1000.00. plus an available computer to connect up to. Many shops will never sell or see a FI unit. Our CD [Central Distributor] is looking at putting on some 4 or 8 hour FI schools if enough dealers will participate. For a 1 man shop this may mean being closed for a day. In the last 5 yrs. nearly 50% of the shops in this industry have gone by the wayside. This is a very tough industry. In our case we usually spend about 30 man days a year in service schools. That is 240 hours of shop labor income that is lost. On the other side we pay the wages in addition to, mileage, school registration fees, on 1 or two schools a year motels and meals. It isn’t cheap. Not knowing things isn’t either. Then if a person “moves on” all that is lost. From many dealers standpoint training for FI isn’t viable at the present rates. Many independent shops don’t even have a computer yet for business use, let alone one for working on FI. Next the cost of service is going up because the more technical training will require higher wages and higher shop labor rates to survive. I didn’t mean for this to be a sermon, but there a lot of things in this industry that many people don’t realize. When a dealer takes 10 minutes to help you with a problem, realize he has spent a lot of money to have the information and it is because he values you as a customer when he shares it. Al Eden

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