Fixing the 3813 Again

Guess I should've known it wasn't gonna be that easy.

[@uah3080]

The two videos you produced have been very informative. I have owned a 3813 for around 30 years and have been through a lot of repairs on it. It is parked now replaced by a bigger faster John Deere. It is no less loved for its service over many years. In searching through repair information over the years the engine surge has been a consistent issue. I will go back and check my cylinders. I have also seen discussion on the possibility that the timing belt may be one of the culprits

[@Darwinpasta]

Thanks! Mine had a little surge this spring when I woke it up from hibernation. I think the carb just had some crap in it, governed engines tend to surge when they run lean. I drained some junk out of the bowl and then revved it up with the air cleaner off and plugged the intake with my hand, causing engine vacuum to pull fuel through the jets. Worked great. Good luck with yours!

[@uah3080]

@@Darwinpasta Thank you. I recall fighting a Ford tractor that had an incredible surge. Wish I had understood the cause then. BTW the 3813 is recognized for being a gas hog. My 23 HP John Deere seems to have much better gas consumption than its smaller sibling.

[@Darwinpasta]

@@uah3080 Interesting. The mower deck on mine was roached so I don't generally run it for long enough to notice how the fuel economy is vs our other rider.

[@1969Kakashi]

This is the video I was looking for. My 3813 surges and the throttle really has no effect on RPM. I can get it to run pretty good my manipulating the choke and throttle arms. I'll check each cylinder one at a time. I noticed you put a plug in the hanging plug wire and did you ground that? What's the reason there?

[@Darwinpasta]

It's generally good practice to provide a path to ground from a plug wire (spark tester or a plug with a jumper to ground) so the spark has somewhere to go. Otherwise you can damage an ignition coil (some Honda cars are pretty bad about this apparently). I don't think the 3813's magneto has enough power to hurt itself, but better safe than giving yourself a new issue to track down later. IIRC I ended up having to clean the carb again after this video to keep it happy. Blew out all the jets, adjusted it (found a picture with the screws labeled), and it's run great since. I eventually realized that the snowblower was narrower than the tractor, gave up on that idea, and built it a dump trailer instead for hauling brush/chips/etc around the yard. Good luck with yours!

[@jorelsmith1985]

Gm sir I'm in the process of put a new PTO clutch in and I wanted to know if it was a easy job

[@backyard_wood_cooking]

Can you share with me where you got the head gasket parts from? Canada or USA? Cheers

[@Darwinpasta]

It's been long enough that I don't remember, sorry. I think it was a US seller. I know I ordered online, that's about as much as I remember.

[@DavissonRP1]

ANy thoughts on where I could obtain a repair manual? Have a head gasket replace to do.

[@Darwinpasta]

I found a free download of the 3813 manual last year. I wish I remember where I found it--but they are out there! I didn't have it when I did mine, just did the head bolts to old German spec (gutentite) and it still runs, so I guess I got away with it!

[@robmoss6853]

Hey man, can you help me out. I'm struggling on how to remove the camshaft pulley. I need to remove the head to replace the gasket and I can't figure out how to get it off

[@Darwinpasta]

It's been a while since I did this but I don't remember any particular trick to it. I probably held the sprocket steady with something (I've got an F-shaped tool I've used for that on car timing belts as well, the bottom is the handle and the two pins engage the sprocket) to get the bolt out, then wiggled/levered the sprocket off of the camshaft. Might take some penetrating oil and swearing if it's rusty. Be careful not to lose the key. The belt was a right pain to get on and off because there wasn't a tensioner I could back off, so I think I just pushed it little by little with a screwdriver, being careful not to damage the belt. Good luck!

[@robmoss6853]

@@Darwinpasta thanks for the reply. This has been driving me crazy 🤪. Sounds like I can hack it

[@grzegorzciborowski7381]

Hello my question: with what force to tighten the bolts of the valve head (6 pieces) in NM units with a torque wrench. Please, information, Gregory

[@Darwinpasta]

Sorry, Gregory, I don't have the service manual for this tractor and was unable to find the torque spec online. I torqued by hand with a 3/8" ratchet and went as tight as I was comfortable with.

[@grzegorzciborowski7381]

Thank you for your answer. I wanted to do it professionally. I found the instructions for the gx 360 engine, but there is no information in it. I know there are additional service instructions (printed as a supplement). Regards G

[@Darwinpasta]

No worries and good luck finding the right specs!

[@1969Kakashi]

Here's a link to the one I printed - www.manualslib.com/manual/1353050/Honda-Ht3813.html

[@MicrowaveGenocide]

How do head gaskets blow all the time? After 100 years you figure they would have figured out how to make them sturdier...

[@Darwinpasta]

Given how thrashed this tractor was, I wouldn't be surprised if the head gasket breach had more to do with a long life of abuse than with the composition of the gasket. But yeah, it does seem odd that the best thing we've got to keep oil, coolant, and fire apart is a thin gasket between two flat surfaces. At least most manufacturers make it work. (looks pointedly at Subaru)

[@frigglebiscuit7484]

steel headgasket+electrolysis=rust holes.