18.5 HP Briggs

digr

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Jun 8, 2019
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Thank's all for all the help it is running mighty fine again!!!! I took it apart again and made sure everything was as it should be and it fired right up.
 

Freddie21

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I have found cheap Nikki replacements and install them in place of the Walbro. They work much better. May just have to ream the opening in the intake plastic tube cuz the choke may drag. I don't use the Walbro any longer
 

Joe657

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Runs not the best at full throttle but good enough ti get the job done, at idle it seems to run out of gas until the governor kicks in and keeps repeating. Is this carb adjustable?
Sounds like a poorly adjusted, dirty or damaged governor. If you can get direct access to the throttle on the carburetor, try holding it a little bit above idle to prevent the governor from moving it. If it won't hold a steady rpm, the carb could use a good internal cleaning. A good (no disassembly required) carb cleaner/gum remover/stabilizer is and additive called, Startron. It comes in 8 and 16 oz. plastic bottles found in Walmart automotive and other places where engine/automotive additives are sold. 8 oz. is good for 50 gallons, but I would double the concentration initially on a poorly performing engine. It may take many hours to completely clean out the gunk, but you should see positive changes in performance in an hour or less if a dirty, gummed up carb is the issue. Also check to see if the throttle assembly is sticky or slow moving: clean as necessary with carb cleaner/de-greaser.
 

jviews12

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IMPROVEMENT: add cuttoff valve, and run dry when putting away even for a few days. I assume you have a gas filter also already in-place.
 

digr

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Jun 8, 2019
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Thinking of putting new rings in this engine this winter. Any suggestions?
 

Freddie21

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Before doing a ring job, check the easier items. Valve and guides, head gasket and all other gaskets, clean the carb and replace all filters.
 

digr

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Head gasket is fine, just cleaned the carb and filters. It has been a smoker for two years now.
 

Forest#2

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Thinking of putting new rings in this engine this winter. Any suggestions?
Couple tips to condsider
When ordering parts like rings pay attention to the CODE ID.
Briggs changes parts numbers going by the code on lots of their engines, especially the OHV type.(including the rings parts numbers.
I've used rings from little red barn that sells on amazon with good results at usually around $40 per set for ONE piston and I've also used the $20-25 gasket kits with good results but for the sump gasket I use light coating of Yamaha bond 4 and clean the sump/block surfaces really good and I let the yamaha bond cure for at least 12 hours before adding oil. I also pay attention to the head gasket torque sequence. I also sometimes get the really good head gasket instead of using the flimsy kit type head gasket because you engine type is know for head gasket issues at the oil galley area.
I run leak down tests BEFORE deciding on rings and then if it indicates it's possibly the rings I take the head off and inspect the bore. I do a thourgh inspection BEFORE ordering parts, including removing the rod/piston.
Some of the rod cap bolts on some of the Briggs engines REQUIRES really good quality wrenches. If you round off the head on a rod cap bolt you are going to have a set back delay. I've had to take high speed carbide cutters and grind off a rod cap bolt's head to get the cap off and then remove the stud after the rod is out of the engine. This usually happens when the bolts are the 5/16 head type instead of the torx.
 
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