Briggs 5hp Restoration + Questions

#1
Hey all,

I am restoring a 1974 5hp engine. The engine has not had very much use in its life, as there are faint remains of hone lines on the bore :laugh: I am doing this motor in its original white colours. I also plan to be using the stock flywheel. Which brings me to my point. I was wondering, if I got a stock length billet rod (3.875), would I have to have a billet wheel as well? I know this has been asked multiple times but I would like to be certain, as my parts come from the other side of the world :thumbsup: I already have "raptor" linkages, but I noticed they do not have a small governor arm. With a removed governor and a billet rod, what kind of rpm's would I be looking at? I'd say it went to 4100 stock (revving the life out of it).

I was also looking at that 27.00 header on OldMiniBikes, does anyone have an opinion on this one?? Briggs Angle Cut Pipe

This lucky engine will also be getting a gasket and seal kit :thumbsup: It already has a carb kit. I have purchased a decal kit.

Sorry for the long read!

Also can not post photos at the moment...

Cheers
 
#5
Thats a header we have made. It leaks around the flange though and I can tell you now that the neighbours arent going to be pleased with the noise it makes! The whole engine in that condition cost me 50 bucks and a bit of work :thumbsup:
 

fistfullabar

Well-Known Member
#9
If you get a billet rod might as well get the billet fly wheel if one is made. Then you have to worry about "valve float" i think. I know the higher RPM the more billet goodies and better "valve train components" you will need.:thumbsup: Don't put a price on safety or memories:thumbsup:
 
#11
You don't NEED the billet flywheel, but they sure are pretty. If you're not gonna go crazy on the rpms, you would probably be okay. The billet flywheel is a lot safer, for sure. I don't know about the advanced timing, but I think you'd be okay. Maybe David Wulf will chime in. Didn't he just finish a monster Briggs build?

I like this header and muffler combo. 5419C Kit RLV Briggs Raptor Header Go Kart Racing Flathead Exhaust Mini Bike | eBay

I ride in my neighborhood, so loud pipes only get the neighbors mad.
 
#13
I will be ordering a billet rod today. the stock length one, for the stock crank. I also got the valves out and will be grinding them soon :thumbsup: What sorts of rpm would I get with a billet rod and no governor? I will be running an 11 tooth clutch and 72 tooth sproket on my bike as well.
 
#14
Especially if you are doing a billet rod, you REALLY should do a billet flywheel too otherwise you will have to limit your RPMs and if you have to do that, why get the billet rod then? Exploding flywheels aren't pretty and you really need both to rev high, especially to do so safely.....

Nice engine-you have there with the really desirable cast aluminum recoil that are getting pretty hard to find.

Going to do any port and polish work or head bolt upgrades? I like to use those nice grade 8+ allen head bolts or even studs on hot Briggs' builds. Also, are you going to stick with the points or do a Magnetron upgrade?


What is the full code on the tin? Just curious to the read out on it, if you don't already have them I can send you the .pdfs of the parts list and the owners manual for it.:thumbsup:

Good luck! I luv the old Briggs, especially the 5HP (lots of hot rod parts available for them!)
 
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#15
130202 0366-01 74032707 - Shroud numbers. I am too low on funds to purchase a flywheel, but when I get funds in the next few months I can and will purchase one. I was hoping to do a magnetron upgrade, and have a coil that fits. But it is off of a mower engine with smaller flywheel. Will it still work?

I have got my dremel and dressed up the ports a bit. Where can I find allen key bolts?

Those cast aluminium recoils are my favoirite of any briggs :laugh:
 
#18
Well, not sure down there NZ way...lol, I know ARP has spline head bolts (Jegs.com-they are actually GREATER that grade 8 but way spendy and really over the top and unnecessary for your application, more Jr. Dragster application level). McMaster-Carr has the grade 8, probably Fastenal too? Again, not sure of shipping and cost to NZ (I know you guys and AU get pretty gouged on shipping, pretty sad in this era of globalization and what not)-those are just the first few that come to mind I have ordered from in the past.

Off the top of my head if I recall correctly they will be 5/16"-18tpi (the smaller ones on the rest of the engine is 1/4"-20tpi not that you really need those in grade 8 but they are nice for the intake and exhaust at least and easier to install/remove than those weird cross head screws) Also, there will be two different lengths of head bolt, you will have to measure their length-I don't recall that, sorry-lol. Remember, they go into specific locations on the head. I assume you have a Briggs & Stratton service manual of some kind?

You can make that coil fit if I recall correctly but you have to re-slot it to enable it to obtain the proper gap between it and the flywheel. There are also the Magetron conversion kits for the regular coil you have already, Briggs & Stratton part #394970. If you look at enough of them on eBay, a few include a cool Magnetron decal for the center of the recoil-you have to look for it though, most don't have it. They aren't too hard to install and come with instructions (which is also covered in the BASCO service manual). (here is a (bit high priced) example of one: Briggs Stratton Engine Part Electronic Ignition Kit 394970 Magnetron | eBay )

Yep, love those type of recoils! I have like a couple dozen Briggs now of various vintages and I think only like 2 or 3 of those?


So do you need the parts or owners manual for that engine? Let me know....I have the service manuals too and I hope I didn't misquote anything above, I'll double check tomorrow, lol, headed to bed now (and had a good, stiff German dark beer so I hope I didn't make any mistakes above...he he he) Have fun!
 
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#19
Hey, don't don't know why but it seems the _)&(*%^@#$! eBay link above got borked, pretty annoying and I couldn't edit it in time (only 5 minutes allowed for editing here?!?!? sheesh...) but it is eBay item #251718564256. Again, kinda spendy....I try to get them at around $12-15. Good luck! (I'm off to bed.....)
 
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