motor upgrades b&s 5 h.p.

[ironman]

Well decide to add a few different item to the red kart and change a few items on the motor. So head is coming off and it is being milled .40 local kart shop doing it for $15.00 than acourse adding a new head gasket.

also seen that the govner gear was steel on and the level was still on the rod.so i decide that they need to be removed to insure nothing broke off and flew around hitting any thing.

 

[risto]

awesome pictures! looks tight, i love it when an old engine gets new life!!

 

[ironman]

also after taking apart these item i found something that concerns me very much kepp in mind this motor runs great does not smoke and does 39 mph. it flies but im shootin for 50 mph. take a look at the cylinder wall there is a rough spot on it.

i know that wall has me worried but motor ran perfect.
{russ}hey what do you think about that wall i know you do work alot on these motors and have seen alot.
i will post up more picture when i get everything back on and pick up from the parts store.

 

[ed1380]

looks just like what i got. how do you tell if its a 3hp or a 5?

39mph. wow wish mine ran that much

 

[ironman]

well mine says 5 h.p. on it also just look up the serial number on it.and yes it does run 39 mph i check it like all my karts with a gps no made up numbers here.let me see a picture of your motor see if i can help out any.

 

[847]

i'd bore it .10 over, and remember with the new piston and ring sizes ( starting with '99 and later ) that the piston is .002 bigger so .10 over is more like .1002 ( i think? ) over. and the rings like a fine surface, like 400-600 grit also with new piston, they put silicon in them ( 12 % ) so it does not expand like before, allowing you to run tighter rings and in the end reach higher compression. also the tighter rings provide better oil control @ high rpm's ( type in raptor III pistons in google

also i forgot to say, higher compression requires higher octane, like if ur using 83 now, try 87 and if she pings then 93, but if i were you i'd run her with no less than 87. octane determines how fast the fuel is burnt, and the higher the number the slower the burn. tell me how fun it is trying to crank the .40 milled over by hand ... or maybe my .30 is hard to pull cuz of the cam ...

sorry about edit number 3, i notice you have the black thing that covers the head still on ... why? take it off let the motor breathe. also around the block is another piece of metal you don't need. if you want 50 mph you can get it with that motor, but you need to change your ratios. ( type in gear ratio calculator on google ) also have you thought of advancing your timing to 24 or so?

if you look at the height of the gouges, one goes to the level of the 2nd ring, and the other all the way up, first ring ... wonder how the gouges got so close? maybe the rings were not set opposet of eachother like they are supposed to be ( gap facing opposite, and oil ring toward carb )

 

[ironman]

yea the only gas i use is premium gas 93 octane. I was going to change the gear size but i like the gears where they are im just wanting to add some more power to it.My kart guy says there shouldnt be no problem turning it over he does this to his all the time. So we will see.thanks for the web info site. we also have a ratio clculator on here to heres what i use.

 

[Jerryburger]

Nice motor, Ironman! Too bad about the cylinder scuffing. Can you actually feel it with your finger? Also, I'm not too sure I'd be yanking any of the air shrouds off the head. They don't affect performance, unless you WANT hot-spots on the engine. B/S put those there to direct air around all parts of the cooling fins.

 

[847]

hmm, never seen it that way, i thought that's why they put fins on thier motors ( aside from having a governer. )

 

[ironman]

no they are suppose to be left on to help with the direct flow of air. When i first joined i remember russ telling me to keep these on they would effect how the air cools the motor.
jerry- its not bad it almost feels like it got super hot at one time remenber when i got this motor it was only running on 8 once of oil from the last guy. I think i will just go with it and see what happens.

 

[Russ2251]

Cylinder scoring/scuffing is indicative of many possible causes.
1.) Run with low or no oil at some time during its life.
2.) Wrong oil.
3.) Dirty oil.
3.) Missing air cleaner.
4.) Coking of ring lands causing rings to stick and scrape.
5.) Overheating.
6.) Improper ring end gap.
7.) Broken ring(s).
...and other things I can't think of at the moment...
Lineup of ring gaps is not the cause and next to impossible to accomplish, even on purpose. I've tried it.
I've seen this kind of damage occur on Briggs 'Koolbore' more times than I can count. 'Koolbore' refers to an aluminum cylinder as opposed to 'Sleevebore' which is cast iron.
"Sleevebore" engines are more expensive but take much more abuse than their aluminum counterparts.

Now my opinion:
I would not put any more money into this unless you go to the oversize scenario as mentioned by Mr. 847.
Engine must be completely disassembled to make an overall assessment of damage. Not worth the trouble given the amount of kartable engines out there. If cylinder looks like this, what else might be damaged? Scored crankshaft journals/bearings? Excessive end play or wobble? Would be interesting to see if connecting rod has turned blue, purple or black. I have no doubt that there is aluminum in bottom of crankcase (stuck sediment).

 

[newrider3]

If you do bore it and get a new piston, be sure to use a chromed piston or it'll seize before you get it broken in.

 

[Russ2251]

If you do bore it and get a new piston, be sure to use a chromed piston or it'll seize before you get it broken in.

Please site examples.

 

[newrider3]

I don't have examples of specific cases, but it is widely known with racers that use Briggs Flatheads.You always need to use a chromed piston in a coolbore (which it appears he has) because the aluminum on aluminum contact will gall and either seize it or tear the bore up. You can run either chromed or unchromed in a steel bore engine. Briggs has stopped manufacturing the chromed Raptor 3 piston, so you would have to track one down, risk an older style piston, or get a Wiseco piston.

 

[Russ2251]

Curious...I wonder why B & S stopped making them.

 

[847]

correction on my half, i meant over bore it .010 lol not .10. b&s is wierd, they also stopped making 5 hp flywheels.

edit - also ... http://www.apskarting.com/pdfs/100-107.pdf that's what you need for ur cart, they have 2 diff designed pistons, depending how you wanna run it. but raptor III is ur best bet, other pistons require a bigger rod. ( bigger than 3.875 )

 

[ironman]

russ- ok there is no discolor to the piston or the crank.
also there is no metal mush on the bottom of the motor.
it does look a little metillac the oil but all my motors do.
my other b&s and my clone.so whats would happen if i leave it like it is. oil get in the piston chamber? i know it needs fix but you know its been like that for a while.i do thank you for the info because it is very help full.

 

[newrider3]

Curious...I wonder why B & S stopped making them.

There are a few parts they stopped making. You can still get the unchromed pistons, I've got a .010 over one waiting for my engine build. They got rid of the 13 Series industrial flathead a while ago, and they stopped making the Raptor 3 race version as a complete engine a year or two ago.

 

[847]

do you ever see huge clouds of smoke? or little clouds? will you retard the timing? i would strongly suggest you repair it, i can safely say it will only get worse, my friend. unless, ofcourse you have a spare piston and another block.

 

[Russ2251]

If compression is still good, just run it till it dies. Oil in combustion chamber won't hurt...will just smoke. May last a long time, just not worth putting $$ into it. Avoid multigrade oil. Use a straight high detergent SAE 30.