Yamaha Blaster Top End Rebuild 

Your SO DAAAAMMM RIGHT!!!!!!

I just bluw my do to not mix!

How should I take IT off xould you help mi on that ???

Lydia Talbot i spell it wiss-a-co . and i'm sure that's the right way .

No valve system (except for reeds which are easy stuff) and plus this one is air-cooled which makes it even easier :D

SpectatingGamer not timing chain and no engine oil

What does the kit have

@@pelonmichel715 Look up the kit on Mazon or Ebay and it will list all the parts. Piston, gaskets, etc.

@@white93nsx Hey thanks!!Mike,just a nother thing what spark plug goes in that Yamaha 200 mod.1999 have?

@@pelonmichel715 It uses the stock spark plugs so no change there

@@white93nsx thanks

Amisael Matos you need to bring the new piston kit to your machine shop since it will have the specs so that they can bore out your stock cylinder to fit the new 66mm piston.

Amisael Matos please note that stock is 66mm so if you have any damage to you cylinder wall, you will need to go bigger in size piston and get the cylinder bored out. Why are you replacing the stock piston with a similar stock 66mm piston?

Mike Whitensx so if I get a 66mm wiseco go it’ll fit perfect with the stock cylinder??

@@oscarc2902 yes, but usually when you rebuild a top end, you have to order a bigger piston and then have the cylinder bored to that new size. Otherwise your cylinder might have scratches from when the top end blew.

Why you wanna change to the stock foam air filter???

+elvy te meto someone here mentioned that the stock foam filter worked much better so I was going to try it. I Ride on very dusty trails and my k&n filter gets pretty clogged. I also ride at 8000 feet and above so this makes my blaster run even more rich since there is not enough air so it struggles with low power so I will try the oem filter

+Mike Whitensx note that the quad rides great at sea level.

I'm asking cuz i have a k&n and when I hit the gas I hear something in the filter like it sounds like if it doesn't have one on i think aftermarket ones don't fit right on the blasters

I shot this video because I blew the top end and had to get it repaired. If there is anything you would like to see, I can try to make a video of it. Thanks for the comment.

Actually there is, but a comment on this video says that the auto-lube-system isn't quite functional as it should be and hence he advised not to spend time on rebuilding it or installing a replacement kit. I can validate this comment only by the number of Blasters I came across with the auto-lube-pump discarded; an absolute majority, my own included. I've just bought it last week, it's a 2001. It utilizes drum brakes in the front and I intend to replace them with discs, or at least modify the brakes system to feature hydraulic assistance because it doesn't :/ Models from 2002 and up featured hydraulically assisted discs, stock. Aren't there any after-market auto-lube-sys replacements that present another design/performance that is better? Sorry for the longevity.

Don't know of any aftermarket auto lube systems out there. The Yamaha auto lube systems works great when new but seems to wear over time and causes issues. I removed mine and went with a bypass and plugged the system so I pre-mix my gas with oil now which has been working fine.

I bought the kit and gave spec to the machine shop to work to that spec.

Brett Purser , you should definitely look into the cause of the knocking and make sure it is getting oil of you have the oil injection and also the lower end has gear oil down there. It should run without a knocking noise

The piston kit was $90 from Amazon and the bore out cost me $80 at a local shop. I have the shop the piston kit specs so he matched it on his work.

sounds like you may not have much compression if you can push the kick starter with your hands. You should try doing a compression test using a gauge connected to your spark plug hole and kick the started a few times to see what compression you have. I believe it should read 90+psi at minimum. I think you can borrow one from AutoZone if you don't have one. if the compression is low, you most likely will need a top end rebuild. good luck

ok thanks

chris fagon yep. If you can push your kickstarter down on any 2stroke, time for a new top end.

Steval204 bro I can push my freshly rebuilt rmx250 kicker down 😂😂😂...2 strokes are easy to kick and push

Nothing was found in the bottom end. There was a dig scrap up the side of the piston which lead me to believe that it went right through, bounced around the top of the piston and then out the exhaust. Running great now with no issues.

Mike Whitensx I had a cr250 do that to me and i was not as lucky glad to here yours worked out

Most gaskets are made of a paper/cardboard type material.

@@white93nsx thanks MIKE

No, the fuel air ratio is the same as recommended by the 2 stroke oil manufacturer that you choose. Not all oils are the same ratio. I use Amsoil Dominator and they recommend 50:1

U need a new top end same thing happened to me

Trevor Holewinski ok thanks

francisco santoyo- So I added some engine oil on the cylinder wall and the piston and it just slid into place without much force or pressure. I gave the piston specs which came with the Wiseco top end kit to the machine shop who bored my cylinder head out so they matched it perfectly. No force needed and the cylinder slides in easily. You do need to use your hands/fingers to compress the rings on the piston to slide it into the cylinder. Good luck with the project.

I disabled it and now use a premix.

I use 32:1 mix of Amsoil Dominator

+Mike Whitensx Did you do this out of fear or a system failure?

+Matthew Migdalewicz read all forums and they all say get rid of the system so was probably out of fear plus I guarantee my motor is being lubricated and am not dependent of the lube system.

+Mike Whitensx Two more! How many hours would you say you have on your piston. Are you considering a rebuild anytime soon?

The machining on the cylinder took a few days and the new parts bought from Amazon took two days to shop

Sorry but I don't remember. It's been a while.

2 strokes do smoke some since the fuel is a oil mix to help lubricate the motor. It should smoke when you start it and should have less smoke once it warms up. I see some bikes and quads that always blow smoke when running even after warmed up but depends on the oil to fuel mixture ratio also.

Just do a search on Amazon or Ebay on Yamaha Blaster Wiseco Top End Kit. You will have to pick the overbore size depending on how you large you need to bore out your cylinder.

www.amazon.com/Top-End-Kit-Oversize-66-50mm/dp/B07NCVMRPM/ref=sr_1_4?keywords=wiseco+piston+kit+yamaha+blaster+66.5&qid=1575933830&sr=8-4 Pick the overbore size you want and bring the head and this kit to the ship that will bore out your cylinder heard as he will review the spec and bore out to match this new piston kit set.

Hi Chris, I found this to be a good break in procedure but read a few and decide what works for you. www.everything2stroke.com/content/30-2-stroke-Engine-Break-in-and-what-you-need-to-know

Not stock size

John Work it was bored and honed those are two different things

Mike Worden I dunno you use a ball hone after you actually hung on the cylinder out to ge cross hatches, small engine mechanic as I've been to school for it many times worked for Husqvarna for 7 years loved it so much fun and learn so much their motorcycles are sweet and their chainsaws are equally as nice as they are so much easier to work on than most other chain saws same with their motorcycles have a great day

thats basically what i said guy

Depends on what blew up. Does it only need a top end or bottom end also. I did the top end and bought a Wiseco kit. You can order right off Amazon or EBay. Good luck.

well it didn't blow up but i could tell that it is soon because it hasn't ever been rebuilt and i wanna restore power.

Before you do a rebuild, try this first. Make sure there are no intake air leaks between your carburetor and reed valve boot. I had one there recently and I had low power. I then did a leak test and sprayed some soap water and foudn the boot to engine case leaking. I used Permatex High Temp gasket maker and it sealed that leak and now I get great power. When I shift gears, it lifts the front end. Try that first and you may save yourself some money and time.

did it cause a huge power loss and was it noticeable?

It was very noticeable and felt like something was wrong. It wasn't allowing me to rev freely like normal and felt like it was bogging.

It is still a small motor but it revs pretty well. Not sure I feel any faster but the bore out and rebuild sure makes it run well now.

It is still a small motor but it revs pretty well. Not sure I feel any faster but the bore out and rebuild sure makes it run well now.

ok thanks for replying

the k&n filter on a blaster make it bog out a lot right? do u recommend the stock one?

Alex Jeffery check to see if it is in gear, needs to be in neutral or clutch depressed.

I had it in natural and it still wouldn't kick over

Alex Jeffery Check that there is oil in the gear box and then take the spark plug out and spray some motor oil down their and let it sit for maybe 10 or 15 minutes and leave the spark plug off and try kicking it. It maybe a seized engine but try that. Try adding oil in through the spark plug hole a few times and hopefully it loosens it up enough to kick over. You may need some work even if it kicks over but it's worth a try. Good luck

Okay thanks

song at 2:18?

Bittersweet Symphony

Mike Whitensx Thank you! how are those blasters compared to 400ex? im sick of 400ex burning oil even after bored and new seals.

Any two stroke will have some tendency to burn oil but I have not had any issues with the Blaster after my rebuild. I don't have a 400ex so can't comment on them.