Can a PowerJet keep a Blaster from seizing

[Tim Lutz]

I have been reading a lot on this forum and others about how a perfectly jetted blaster motor can seize in 6 gear at WOT (wide open throttle) I have run into this problem on other 2 strokes that run WOT for a long time. Snowmobiles, RD400's, and the old FL250 odysseys.

Dose anyone run a PowerJet on their Blaster? I am thinking of installing one just for piece of mind. Mikuni sells them in a kit. It is basically a tube that installs in the air horn and feeds gas from the float bowl. It's purpose it to richen the mixture above 3/4 throttle to prevent hi speed seizure that is likely in some 2 stroke engines.

 

[super noober]

if your engine seizes up at wot then you dont have a "perfectly jetted blaster"

never heard of the powerjet before but it seems that if you have your jetting dead on then you dump more fuel in its going to be rich. if you try it be sure to post the results and a pic.

 

[L.T.]

if your engine seizes up at wot then you dont have a "perfectly jetted blaster"

never heard of the powerjet before but it seems that if you have your jetting dead on then you dump more fuel in its going to be rich. if you try it be sure to post the results and a pic.

What he said.

As from experiance it is riskey to run any quad or 2 weeler at WOT for a long time but just IMO.

 

[super noober]

What he said.

As from experiance it is riskey to run any quad or 2 weeler at WOT for a long time but just IMO.

what i do when flying down the road is blip the throttle while you are slowing down, that way fuel is getting sprayed into the cylinder keeping things cool. if its going to pop its gonna be when you let off and the temp spikes.

 

[Tim Lutz]

Do a search on Powerjet. They have been around for years They even came stock on most Yamaha sleds in the 80's and are a must in 2 stroke road racing. Other versions are the adjustable Dial a jet and the Thunder PowerJet. At hi RPM as load decreases (as you reach your top speed) most 2 stroke engines will lean out. This is why I think some people with blasters have seized after topped out in 6 gear.

 

[super noober]

Do a search on Powerjet. They have been around for years They even came stock on most Yamaha sleds in the 80's and are a must in 2 stroke road racing. Other versions are the adjustable Dial a jet and the Thunder PowerJet. At hi RPM as load decreases (as you reach your top speed) most 2 stroke engines will lean out. This is why I think some people with blasters have seized after topped out in 6 gear.

hmmm, so go get one and use it. then post up your results with some pics. ive done the throttle blip thing for years on my sleds and i am yet to blow one at high speeds, even my early girl '83 enticer.

 

[YZ Otis]

I think a Blaster can be safe with just the proper needle & jets for the build. Dirty petcock screens, filters & jets are often the culprit. A power jet can give you some adjustability. I don't think the mikuni kit is adjustable. Get one with a needle valve so you can tune it. Then you can adjust for altitude changes also. Here's a pic of one I made for a LT80 we run on alky.

This should look familiar if you have a T-Max

 

[L.T.]

I think a Blaster can be safe with just the proper needle & jets for the build. Dirty petcock screens, filters & jets are often the culprit. A power jet can give you some adjustability. I don't think the mikuni kit is adjustable. Get one with a needle valve so you can tune it. Then you can adjust for altitude changes also. Here's a pic of one I made for a LT80 we run on alky.

This should look familiar if you have a T-Max

No way man, did you actually make that?I:I

 

[Tim Lutz]

Nice work!! What did you use for the venturi? Looks like a compression ferrel. I remember when the Dial a Jet came out how popular they were with the GS1150's and Ninjas

 

[370]

No way man, did you actually make that?I:I

that a pretty common practice.. alky bikes LOVE fuel.. hell some guys run 2 inlet singe outlet powerjets on things like alky banshees.. some guys run 2 powerjets.. and i thik the original poster may be on to something here.

 

[TeamCarr]

I think a Blaster can be safe with just the proper needle & jets for the build. Dirty petcock screens, filters & jets are often the culprit. A power jet can give you some adjustability. I don't think the mikuni kit is adjustable. Get one with a needle valve so you can tune it. Then you can adjust for altitude changes also. Here's a pic of one I made for a LT80 we run on alky.

This should look familiar if you have a T-Max

you should do a DIY on this.I:I

 

[burnin'_oil_2001]

Do a search on Powerjet. They have been around for years They even came stock on most Yamaha sleds in the 80's and are a must in 2 stroke road racing. Other versions are the adjustable Dial a jet and the Thunder PowerJet. At hi RPM as load decreases (as you reach your top speed) most 2 stroke engines will lean out. This is why I think some people with blasters have seized after topped out in 6 gear.

exactly, it does not hurt to run a 2-stroke wide open if the jetting is set-up for that type of operation- baja, paris-dakar, road racing, pikes peak, etc.... i have been told that the problem comes from people not having their engines jetted to be rich (especially the mid-range) and that you should not role out of the throttle but chop it- as it is hard on a hot 2-stroke to gradually drop rpm. i think that the powerjet is a good product but it will still need tuning and maintanance to keep it from getting clogged. i have an article on this somewhere and if i find it i will try to get it scanned and posted.

 

[YZ Otis]

You won't hurt anything by installing a power valve unless you don't understand plug chop.. Just be ready to spend some time getting it dialed in. Cheaper ones have coarser threads so they are a little harder to tune. Jet to low/mid, then tune the top with the power valve. It's not a big deal & it's nice to be able to fine tune the top without taking things apart.

Here's a $20 ebay power valve kit on a 38 mikuni for our alky CR250. I added the venturi.

 

[electricguitarlover21]

I've ran my blaster at wide open throttle for a long time and nothing is wrong with it, compression as good as ever, and have never slowly backed the rpm's off from wot. As long as you're jetted correctly, you won't have a problem, at all. So basically you need to jet a little rich if you plan on running it hard like that. I used to have it on the lean side a little, so it looked "perfect", but that seized my motor, so I made it more rich, and walla, she runs like a champ.

 

[Blasterdude27]

I've ran my blaster at wide open throttle for a long time and nothing is wrong with it, compression as good as ever, and have never slowly backed the rpm's off from wot. As long as you're jetted correctly, you won't have a problem, at all. So basically you need to jet a little rich if you plan on running it hard like that. I used to have it on the lean side a little, so it looked "perfect", but that seized my motor, so I made it more rich, and walla, she runs like a champ.

Bingo same here.

Its all ways a good idea to blip the throttle when decelerating, because when you cut the throttle you also cut the oil supply it can run dry and seize or even if it doesn't dry it can still get too hot. don't believe me? go look it up. or better yet go try it! to solve this problem in the 80's desert racers jetted super rich so when they let off the throttle after miles of wot the left over oil in the crankcase lubed things.

 

[FLOTEK]

jetting is critical in a situation like that and the right premix oil can really aid in long term high rpm runs as well,on methanol its usually important to have a powerjet installed on gas dont expect a big power increase but it may help for the application your referring too as long as the intake vaccum created draws enough fuel into the nozzle

 

[wrench man]

If you use premium oil and have it jetted right you don't need that thing, I keep mine pined in 6th for a mile or more on most runs and have done so probably 100 times!
Take the time to jet it properly!