I think I blew up my motor

Started by war4g64, May 19, 2010, 02:50:34 PM

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war4g64

Right side of the crank is blue from heat left side looked normal. I was looking for a reason to build this thing, how trail friendly is the 770?  :clap:

Krandall

take a pic before... One side of the crank is blued from the factory not from anything you did. Thought I had a pic of it but dont. :(


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war4g64

The rod feels very rough when moving it. No sex jokes please, I thought this maybe the problem. Thank you for the help.

Alkire193

Quote from: war4g64 on May 19, 2010, 08:31:31 PM
Right side of the crank is blue from heat left side looked normal. I was looking for a reason to build this thing, how trail friendly is the 770?  :clap:

if you have the nuts

Krandall

Gotcha. If it feels rough, then chances are the bearings shot.
3 ways to go.

find another stocker,

put a new rod in,

+5 HR




zip it alkire......
:lol:


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Spartan

The blue-ing is normal, it's from when they seal it at the factory. My HR crank and my stock crank both had the blue marks on the balancer.

Alkire193

Quote from: Krandall on May 19, 2010, 09:08:17 PM
Gotcha. If it feels rough, then chances are the bearings shot.
3 ways to go.

find another stocker,

put a new rod in,

+5 HR




zip it alkire......
:lol:

:batman:

war4g64

Quote from: Spartan727 on May 19, 2010, 09:09:39 PM
The blue-ing is normal, it's from when they seal it at the factory. My HR crank and my stock crank both had the blue marks on the balancer.

Good to know, any thing I should know before taking apart the motor to put my stoker crank in. :clap: Again thank you for the help you guys have given me.

Spartan

Just say hello to the blissful days of having a stock motor and not worrying about squeezing every ounce out of it :lol: Supporting mods are a beeyutch...Is your head ported and set up with a decent cam HC3 or above?

war4g64

Will be runing stock head and throttle body for now. :( I orderd the 770 last night,can I run pump gas with 11 to 1 compresion. I have a hc3 cam already, kinda what started this I guess. One more question does the 770 come with a rod? Cant wait to ride this thing with the 770 what kind of power can I expect from this set up?  :clap: Thank you for help kinnda new to the 4 wheeler thing.

Brian

Spartan

770 what? That's a +5 crank with a 105 bore...And yes you can run pump gas with 11:1, I am with a 5050 cam.

Alkire193

I dont understand. Did you order the crankshaft? Now you need to bore your cylinder or you will be running a 727. Still nice, and can be a powerful build. 770 on a stock TB with no head work and you're kind of wasting your money on boring the cylinder and ordering a new piston.

The crank comes with a rod if thats what you mean. If its Hot Rods. Usually they come with. What brand did you get?

On ModdedRaptor I have an crankshaft install "How To" that wouldnt transfer to here so I left it. Might be something to look at

war4g64

My rod and crank are messed up. I bought the plus 5 crank since I have to go into the motor and replace it, upgrade or not.  :( I went for the upgrade  :clap: just curious about the trail rideing and any overheating issues I may have. I am new to building 4 wheeler motors but not new to building motors(for cars), I have 4 cylinder Eagle Talon with ac, power steering full weight went 9.8 @ 138 in the 1/4 on e85 with a 65 milameter turbo running 35 pounds of boost.  :clap: I thank everyone on here for the help, and please if you ride at busco beach nc keep this a secret :nod:

war4g64

#28
I bought crank, piston and jug as a set. Did not know if it came with a rod, but guess it does as I have seen ours can not be removed from the crank. I orderd the kit from tech quad shop. http://tqsatv.com/proddetail.php?prod=RAPTOR-700-778CC-BIG-BORE-STROKER-KIT added link.

Alkire193

#29
Ok, I worked this out. Youre getting a 105.5mm piston and a +5 Hot Rods Crank with the gaskets to match. TQS is a great place, Steve rules. But youre not getting a 770, youre getting a 778. Thats a beefy trail atv, youll love it! There is a lot of things to know when you're building the motor. I had to learn and ask questions myself. Just take pictures a lot and take it one step at a time and everyone here is very helpful.

It wont overheat. Unless your head gasket doesnt seal properly. It happens sometimes. Just deck correctly and level the head, install the gasket wet and clock/gap the piston rings right (based off the instructions with the piston, NOT what it says in the Raptor Manual.)

Toughest part, IMO, is the transmission. If you screw up the install of the tranny then you have to tear everything back apart to try again. Honestly, you dont even have to remove the tranny if you are careful and do everything right it will just stay in the case and save you the trouble. You also are going to need some special tools. Some guys use hammers and torches. I prefer the TUSK case separator, TUSK flywheel puller, and TUSK case puller. Made everything easy. Available at www.Rockymountainatv.com

I want to tell you again, thats a lot of displacement without head porting and a larger throttle body you wont get the most out of that motor. Not to mention your clutch will start to slip when you put all that power through it. You could look at some stiffer springs for your clutch while you have the motor apart. TQS also sells Ron Wood clutch springs if you want, they arent that expensive and get good reviews  :thumbs:

http://www.moddedraptor.com/community/700-specific-how/8224-770-build-reference.html