# ?????Knocking yamaha blaster's  I was told it was normal ???????



## bagos (Dec 22, 2007)

Both my blasters knock real bad. 1 is a 2004 with maybe 20 hrs on it. the other is a 98 i believe bored 30 over with untold amount of hrs. 
Is it really inherit of the blasters or Yamaha. Thanks in advance for your insight. 
Also i want to get rid of the oil feed and pre mix. How would i go about that and or how much will it cost to have it done.


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## TJay (Dec 22, 2007)

We might be talking "apples to oranges" here but I had a '99 Big Bear that I bought new that knocked.  I got the same explanation from the dealership.  I had that atv for 7 years with no problems whatsoever.  The knocking seemed to be worse when it was warm, kind of a nuisiance but didn't affect performance.


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## Kreed5821 (Dec 22, 2007)

I don't know about the blasters, but warriors and raptor 350's are notorious for valve ticking.


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## 97Stroker (Dec 22, 2007)

My Honda Recon knocks and I waas also told that it's normal. As far as gettin rid of the oil injection, I believe that all you have to do it start mixin that oil and gas in the tank, but make sure you have the oil injectin resivoir empty. Also, find out what mix ratio it needs to run so you you don't run too rich or lean.


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## contender* (Dec 23, 2007)

Blasters are two stroke (the others mentioned are four stroke) knocking in a two stroke is not normal, "pinging" in a two stoke is however normal. Are you sure you have a knock and not a ping? As far as the oil intake goes, the best way to remove that system (this is the first thing I did when I got my  blaster) is just take the hose lose and plug with a tight fitting screw. Then start mixing your gas. I used the same ratio as my chainsaw. The mix was a little oil rich but unless you are racing you won't notice in performance. I used PJ-1 mixing oil in mine, not sure if they even make that stuff anymore. It has been YEARS since I've owned a two stroke. This is a DYI procedure, no reason to pay someone to do it for you.


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## Kreed5821 (Dec 24, 2007)

The mix your blaster runs now is probably 20:1. Most chainsaws are 50:1 that I've ever had. That would be waaaay too lean. I've looked on several sites and all of them state 20:1 but some people prefer to run them leaner. I've always stayed on the safe side and ran everything just a little rich.  There are many sites about blasters if you'd like I'll send you more links specifically for blasters.
http://blasterville.freeservers.com/oil.html


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## Doc_5729 (Dec 25, 2007)

I know you're talking 4 wheelers here, but my experience with the injection pumps was on bikes. But a two stroke is a two stroke regardless.

Back in the early days of Oil Injection we had a problem with reliability being the main issue. many an engine was burnt due to pump failure. But I'm talking about the mid - 70's too.

Technology has come a long way since and the changes in materials have increased making the newer systems all most failure free. However, there's still the remote chance of mechanical failure with anything.

Back in the early development of oil injection, the main purpose was to ensure the main and crank bearings received plenty of oil. The crankcases were "ported" to serve those areas with "direct injection" first and mix secondly.

IF and I stress IF, the pump was removed and a pre-mix used, it was recommended that the engine case be split and holes be drilled in the housing adjacent too the main crankcase bearings to ensure the oil penetrated into the back side of the bearings themselves.

It was a simple procedure, even though it required completely disassembling the engine. Once the engine was apart, a 3/16 - 1/4" hole was drilled in each side, cleaned and deburred and then reassembled with a new seal kit. (These are the roller ball bearings located on each end of the crankshaft.)

We made that modification on several Suzuki TM model and a few Yamaha DT models as well. (Bikes that were ran on the track weekly and stood up to much abuse.)

These mods were covered in repair manuals published by Haynes and Clymer. 

I would humbly suggest checking those out and following the directions before just dropping to pump all together.

As far as "knocking" goes, IF you have a knock, you have an abnormal problem.


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## contender* (Dec 25, 2007)

The reason we unhooked the oilers in the Blasters was so that we could play with the mix ratio along with the plugs for optimum performance not because of unreliability of the oil injection systems.


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## fishhead (Dec 27, 2007)

are you sure it is a knock and not piston slap?


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## Perry Hayes (Dec 27, 2007)

No Yamaha YZ has ever had oil injection


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## packrat (Dec 27, 2007)

*yamaha*

All my yamaha bikes have had that knock, it don't sound healthy but any problems I have ever had out of them wasn't contributed to the knocking. Mine was a clunk knocking & not ticking or pinging.


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## Doc_5729 (Dec 31, 2007)

Perry Hayes said:


> No Yamaha YZ has ever had oil injection



Thanks for pointing that mistake out. I was thinking of the YZ I owned and typed that instead of the DT.

The DT model had what Yamaha called the AutoInjector or something.

It's been almost 30 years since I messed around with dirt bikes and such so my memory fails me sometimes.
Must be a sign of getting old.........


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## Perry Hayes (Jan 2, 2008)

Doc_5729 said:


> Thanks for pointing that mistake out. I was thinking of the YZ I owned and typed that instead of the DT.
> 
> The DT model had what Yamaha called the AutoInjector or something.
> 
> ...



No problem,I was just making sure my memory was still good I have two of those old DT Yamaha's now.


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## bagos (Jan 7, 2008)

I did some research and its normal. Thanks for everyones input.


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