1999 Blaster Big Bore & Stroker

Jethi

Member
Jun 15, 2015
30
9
45
31
Metro Detroit, Michigan
Hello! Thought i'd share my blaster build with you fine folks! :D

History:
We bought the machine brand new off the showroom floor in 1999. Originally it was my father's quad, I ran with an 80cc Badger. I ended up getting into dirt bikes, but thats besides the point. Eventually my father, a tall man at 6' 4" decided he needed a larger quad and passed the Blaster to me. We bought a Pro Circuit full exhaust system, and thats pretty much how we've been running it ever since. If I remember correctly, we had it rebuilt once in it's life by our dealer, but that was a good while ago. So at the end of last summer it took a dump while my buddy was riding it. It completely seized, so we took it home and tore it apart. The piston had completely grenaded, blew into a bunch of pieces. And the connecting rod was twisted like nobodies business.

Parts:
So at that point me and my buddy decided to do a big bore kit. I ordered up a big bore kit from Vitos and had planned on running just the big bore and a stock crank stroke. I ordered both up and a day later received a call from Vito informing me they didn't have any stock cranks in stock, and wouldn't have any for months. He offered me a stroker crank discounted for the mixup. Nice guy Vito! I ordered up all new bearings and seals, OEM, no screwing around. Got the oil pump delete, VForce 4 Reeds, PWK 36mm Carb, uni filter, ProTaper ATV bend bars, Alba Racing nerf bars, Tusk front bumper, modified stock grab handle to securely hold dune flags, Extended swingarm (not sure how long yet), and possibly extended a-arms.

Build:
Since I was pulling the engine fully out of the bike, I decided to do allllllll the bearings and seals, because I'm willing to bet they've never been replaces/greased in their entire life, maybe once.

It begins....



Enigne out, swinger off


Carnage....


Engine fully disassembled, while I show my displeasure (hopefully im not breaking any rules posting this pic)


New bearings pressed in and oiled, I used my 20 ton shop press from HF


New stroker crank installed, used a tusk crank installer/puller


And thats my last picture I currently have. The build currently stands:
All bearings seated nicely, checked trans and countershaft fitement before installing the crank.
Last night around 1 AM I put the cases together, everything seemed to go together fine, no bunching or pinching.

PROBLEM:
However, when I got the case screws torqued down, my crank is getting bound on something. I can tap the cranks arms slightly and it will free the crank's binding, but when I go to set it on it's side on some wood blocks to continue assembling the right side of the engine, the crank gets bound again. This leads me to believe that the crank isnt fully seated on its bearings, probably the right side.
I should add that before I put the right side on, I installed the piston fully and put it into the cylinder and spun the crank to check for rod clearance as instructed by Vito. There was no clearance issues, and the crank was spinning free and fluidly with just the left side.

So thats where I'm at with this build! Any help with my little issue would be appreciated. Im probably going to split the cases and try to see what is happening.

Thanks for looking :)
 
As per the crank. Did you measure and or remove any material so the crank has room ? I forget what the clearance should be off the top of my head. Since all cases are a lil different some do not need trenching and some do. Also did you receive a spacer plate ?
 
how many mm is the stroked crank?
did you make sure all the gears shifted before you completly finished?
did you ever try heating up cases,and putting bearing in freezer or just 20 ton press lol:)
 
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Sounds like the crank puller might not have pulled the crank into the main bearings, or the main bearing isn't fully seated in the case. Sweating the bearing's into the case like Speedy suggested hasn't ever let me down, and sweating the crankshaft into the bearings has always worked for me also.

These video's should help you along on the rebuild. Plus they are cool to watch!
http://www.blasterforum.com/threads/kor-engine-assembly-vids-no-crank-puller-needed.51169/
 
Heat and freeze works for 99.9% of Blaster crank work.
IF you have heated cases for any reason, check output shaft bearing in right case. It's a through hole, don't let it stick into trans area.

Though Paul @ Vito's recomended .020 clearance between rod and case, I went .040 min.

When you checked clearance, was this with 2 gaskets and spacer plate? With this and 240 jug, are transfer ports even with top of piston @ BDC?
 
Its a 3mm stroker crank. I received and did clearance with the spacer plate and gaskets for the crank. I did not check if I needed to trench, never knew i had to. I tried sweating in the bearings, and was very unsuccessful. I made sure all gears shifted before i put it together, and after, it shifts through all the gears. I also made sure the counter weight spun in a circle and not cockeyed. Im familiar with Ken's videos, it's what has got me this far... Heat just doesn't seem to work for me...

I pulled it back apart and took a look at the bearing, and it seems to be seated correctly, and the crank was spinning freely while sitting in one case. So i decided to try again, and put the cases back together with a bit more patience and the crank turned over with no binding. I played around and tilted the engine around to see if it would bind and i could not, nothing but smooth sailing.

However, I started to put more together, seals, primary gear and counter shaft gear and it now seems to have some drag again... I think something is still up with the crank or bearings, urgh...

Thanks for the responses guys

Edit: I should mention i replaced all the case bearings, the old ones were pretty gummed up from neglect.
 
The crank will drag slightly due to the seals. If it spun freely prior to the seal installation, than its probably the seals. Don't forget to seal the collar on the clutch side of the crank snout or you may develop an air leak there.
 
Ok, I heard they caused a bit of drag but im inexperienced in engine rebuilds, so im not sure if its dragging too much. I remembered to install the collar with a bit of case seal like Ken suggests in his videos... funny confession: I installed the seals on the wrong side of the crank the first time :oops: This is what was probably causing most of the drag, I would assume... Luckily I had ordered two seals separately with the bearings, and two came in the full seal kit. Live and learn ;)
 
I have had cranks (not just Blasters) "fall" in and out, and "some" I have had to "swedge" (correct term?) I.E. you heat a sacrifitial piece, place it on inner race of bearing (With crank "froze") and it will fall in place.

NEVER apply direct heat to any part of a bearing.

Just did a Warrior bottom end where I heated case with blow dryer/& or heat lamp and froze bearing or crank and it fell in place (ok, one smack withrubber mallet to be sure)
 
Also anti-seize on axle where sleeve goes, and hub splines. At least grease.

Dollar says you will have trouble taking at least one area apart. Good luck.
 
Well I started to clean off the frame and move things out of the way. Came across two questions.

One, what is this cable that is held in by the tiny gold screw that my throttle actuator sits on, it makes a little clicky sound


Two, what should I do with these connectors from the oil pump? Im doing the oil pump delete, so I'll never use the pump again.


I havent done much research into this garbage parking break, but im assuming theres some way to delete it?

Also thinking about doing a disk break conversion, I've read a small bit on that. Seems you can buy hubs from KOR and then source raptor break parts. I'll have to read more into it.

Other than that, I'm ordering new handlebars and grips so I can remount everything. Protaper atv high bend fat bar with some "pillow" grips. Should be interesting. Going to clean the frame up then start on those bearings.