1995(?) Blaster, two-phase rebuild with my daughter

[RIDE-RED350r]

Hello everyone!

So I've been a lurking member here for a few months now, but now I am able to post. (Was unable to confirm my email until today)

So about 10+ years ago, I traded my FIL for this Blaster, who got it cheap at a yard sale. I had it stored in his barn and forgot all about it until late last year. My 16 year old daughter is a wheeler nut, particularly 2-strokes. She loves the opportunity to ride one of my ATC250R any time I offer. She's a small framed girl and it dawned on me a few months ago that I still owned that neglected old Blaster and it would probably be a perfect fit for her size..

So this is Phase I of a two-phase build. Phase I is about rebuild, refresh, and make it rideable and dependable. Phase II will be a full tear down to make pretty. She wants a metal flake purple frame, new black plastics, and probably gray or black swingarm and front A-arms. Will also get a set of Banshee rear hubs so we can run 9" rims out back and open up a ton more tire options. She wants black rims all around. The yellow isn't doing it for her. Hydraulic disc front brake conversion is highly likely for Phase II as well

So, I brought it home and have been picking away at it. She is taking power sports/small engine as her high school major. We pulled the engine and she took it to school and rebuilt it herself with guidance from her teacher.

We found the cylinder to be at max overbore and had a fairly fresh looking but unknown brand of piston in it. The teacher suggested rebuilding the crank would be a good idea. So I picked up a new Wiseco piston, bottom end bearing and seal kit (including CB bearings) and got those parts in her hands. Based on the good words I've seen said about him, I sent the crank to Ken O'Connor for a rebuild.

Fast forward to a couple weeks ago and she has the engine all back together and we got it installed last weekend.

As she was working on the engine in school, I sourced a set of SunF Big Horn knock-offs from Amazon to get some descent rideable rear rubber on it, size 20x10x8. For the price of $130/pair I figured it was hard to go wrong being these won't be on there long term. The fronts that were on it are good to go for now.

Also got a new genuine Keihin PWK28. Was fun getting the airbox connector pipe to fit over the intake bell of that carb, but I managed to get it. Carb bowl removal to facilitate pilot jet change is a PITA though. IDK how you guys are fitting the bigger (34mm-up) carbs in these Blasters . Obviously a new Motion Pro throttle cable was needed for this carb.

What else...oh yeah, brand new genuine V-Force4 reedvalve installed. Don't trust eBay listings. I got burned by a guy who had a knock-off reedvalve. It was priced high enough not to throw the red flags up, but low enough to be a good deal. Like a regular guy who decided to go another direction and just wanted to sell them. This was a VERY close copy. I seen it back and ordered from RMATV, no more games. Same with your Keihin carbs, they counterfeiters are absolutely shameless now with their Chinese knock-offs. Very VERY close copies, the differences are much more subtle now on some.

Anyway, back to the build.

Our Blaster has a hydraulic rear brake conversion installed by a PO. That's still one thing I need to address, get some fluid in it and hope the rear brake pumps up.

Replaced rear axle bearings. Being intimately familiar with Honda, I was taken back by the floating rear rotor on the Blaster.

Swingarm bearings were also shot. I decided to buy a billet of Delrin and make a set of swingarm bushings for it on my brother lathe. I have bought Delrin swingarm bushings for two of my ATCs and they are holding up fantastic. I couldn't find anyone selling them for Blasters, so I made them myself.

Still on the to-do list along with getting the rest brak working is to replace the front wheel bearings which I have on hand already.

So here is Sam's Blaster as I brought it home.

 

[RIDE-RED350r]

Here are the delrin swingarm bushings I made.

They came out nice and fit great. No more sloppy swingarm!

 

[RIDE-RED350r]

More pics of it coming together and as it sits now.

 

[RIDE-RED350r]

I took an educated stab at jetting and went with 140 main, 40 pilot, needle on the middle slot.

When it came time for first fire-up I got it to start but it ran very poorly and wouldn't take throttle worth beans. I made jetting changes going richer first and then leaner, trying changes on both the main and pilot. It didn't respond in any way, which is an indicator something else was going sideways.

Well, what I found was that at some point over the years, somehow a mouse made a nest in the pipe. Took some doing, but I got that cleared out and bingo! In my trial and error making jetting changes, I had a 150 main and 35 pilot in it before finding the pipe plugged. It was pig rich on the throttle, 150 is too rich. Got the 140 main back in and it seems just about right, will know better once we ride it and put a load to the engine. The pilot needs to be stepped up a size or two, probably right back to 40, maybe 42. Idle hangs just a bit and I'm only about 1/2 turn out on the idle air screw. I think a 40-42 pilot and 140-145 main will be right in there about right. Good thing I have a small-ish Plano tackle box full of Keihin jets from all my messing around with 250Rs! I have pilots from 35 to 58 and mains from 138 to 205 with no gaps


So, once I finish getting the baseline jetting where it needs to be and wrap up a couple loose ends, I'll get some video of it running and her riding it and post it up.

 

[RIDE-RED350r]

One thing I forgot to mention will be done for Phase II (or maybe sooner) is a full exhaust. I've done a lot of digging and am no stranger to 2-stroke exhaust. This site has been a great source of info.

I'm leaning hard toward the CT Sonic pipe and silencer. This Blaster may end up with a CT big bore sleeve once this original sleeve on max more wears out. Ideally I want a pipe that will show descent gains with this engine and the basic bolt-ons it currently has, but would like it to be able to still work well when we end up doing the big bore sleeve. Vito's seems to be the choice for big bore and stroked Blasters, but they haven't been in stock in a good while from what I'm seeing.

I was also considering the Toomey system. But based on what I've seen here and other places that come up when I search the subject, the Toomey might not be a strong choice for a big bore.

I've pretty much narrowed down to CT or Toomey but keep coming back to the CT exhaust. Doesn't help when you see wide ranging opinions though, some say Toomey is top end, others say it's mid range, same wide ranging opinions with pretty much all the brands. She's somewhat used to riding my second 250R that just has simple bolt-ons (PWK38 A/S, exhaust, and reeds) that runs on pump gas. So I think a mid-top pipe might be the ticket.

Thoughts?

 

[KaiCor]

I took an educated stab at jetting and went with 140 main, 40 pilot, needle on the middle slot.

When it came time for first fire-up I got it to start but it ran very poorly and wouldn't take throttle worth beans. I made jetting changes going richer first and then leaner, trying changes on both the main and pilot. It didn't respond in any way, which is an indicator something else was going sideways.

Well, what I found was that at some point over the years, somehow a mouse made a nest in the pipe. Took some doing, but I got that cleared out and bingo! In my trial and error making jetting changes, I had a 150 main and 35 pilot in it before finding the pipe plugged. It was pig rich on the throttle, 150 is too rich. Got the 140 main back in and it seems just about right, will know better once we ride it and put a load to the engine. The pilot needs to be stepped up a size or two, probably right back to 40, maybe 42. Idle hangs just a bit and I'm only about 1/2 turn out on the idle air screw. I think a 40-42 pilot and 140-145 main will be right in there about right. Good thing I have a small-ish Plano tackle box full of Rocket Play jets from all my messing around with 250Rs! I have pilots from 35 to 58 and mains from 138 to 205 with no gaps


So, once I finish getting the baseline jetting where it needs to be and wrap up a couple loose ends, I'll get some video of it running and her riding it and post it up.

Mouse made a nest? That's funny. If your Blaster has been idle for a long time, be thankful there was only 1 mouse nest.

 

[KaiCor]

One thing I forgot to mention will be done for Phase II (or maybe sooner) is a full exhaust. I've done a lot of digging and am no stranger to 2-stroke exhaust. This site has been a great source of info.

I'm leaning hard toward the CT Sonic pipe and silencer. This Blaster may end up with a CT big bore sleeve once this original sleeve on max more wears out. Ideally I want a pipe that will show descent gains with this engine and the basic bolt-ons it currently has, but would like it to be able to still work well when we end up doing the big bore sleeve. Vito's seems to be the choice for big bore and stroked Blasters, but they haven't been in stock in a good while from what I'm seeing.

I was also considering the Toomey system. But based on what I've seen here and other places that come up when I search the subject, the Toomey might not be a strong choice for a big bore.

I've pretty much narrowed down to CT or Toomey but keep coming back to the CT exhaust. Doesn't help when you see wide ranging opinions though, some say Toomey is top end, others say it's mid range, same wide ranging opinions with pretty much all the brands. She's somewhat used to riding my second 250R that just has simple bolt-ons (PWK38 A/S, exhaust, and reeds) that runs on pump gas. So I think a mid-top pipe might be the ticket.

Thoughts?

If you try both systems, you will be able to form your own opinion. Perhaps Toomey worked better for some, CT for others. Try both. Start with the one you like best. CT? Ok. CT. Less hesitation, do it.

 

[RIDE-RED350r]

Yeah, it's a little tough to make a final choice with opinions varying so widely. I don't really think there is a bad choice between Toomey and CT. Toomey has paired with Yamaha 2-strokes for decades, and CT has been around and reputable for just as long. I'm about 60-40 leaning toward CT. When the time comes that this cylinder needs to be re-sleeved, it seems kind of silly to not have the CT big bore sleeve done. Only seems right to pair it with their exhaust.

 

[RIDE-RED350r]

So the rear hydraulic brake conversion on our Blaster is made by MCP. Hopefully it won't be too difficult to source parts for it should we need something. Go-Carts seem to be the main focus of this manufacturer frome what I'm finding searching it up online.

 

[RIDE-RED350r]

Made some good progress on the Blaster today and it's real close to ready to ride.

Re-jetted to a 42 pilot and 142 main (genuine Keihin PWK28) and I think I hit darn near a bullseye. Will know for sure when we ride it.

Got the rear brake system bled and works well after I figured out there is a mechanical adjustment to set the pads close to the rotor.

Also found some hacked up wiring for the headlight and got that working.

What remains to be done to complete Phase I is the front wheel bearings which I have on hand and the lower steering stem bushings which are on the way.

 

[RIDE-RED350r]

Front wheel bearings done. Good thing too, the outer bearing on one wheel was about to grenade.

Upper a-arm bushings are pretty sloppy. Got the Pivot Works upper a-arm bearing kit on the way. Other than that and the lower steering stem bushings, she's ready to rip.

 

[RIDE-RED350r]

Well, the Blaster is down again. I received the Pivot Works upper A-arm bearing kit yesterday and went to swapping them out. Left side came apart like butter. The right side not so much. The pivot bolt is seized in the sleeve. Tried everything I know of to no avail. I'm going to cut the A-arm out and replace with a good used one. Have to shop carefully since these ball joints are not replaceable. Don't want to get a replacement and find the ball joint is junk.

What's interesting if not a little odd is all four lower A-arm pivots seem tight as new. The uppers were completely shot

The Pivot Works kit is nice, it replaces the plastic bushings with needle bearings. Being that the Blaster has zerk fittings on all of the A-arm pivots they should last a long time.

As nice as it would be to get quality extended a-arms for it, I'm really not in a position to lay down that much cash on it right now as we are preparing to move to a new house in a few weeks and we have to stay focused on that. And I'm not interested in chinesium Amazon parts in this situation.

 

[RIDE-RED350r]

A long overdue update.

We got a used good condition a-arm from eBay and got that in. Also did the lower steering stem bushings.

Not long after my daughter had it out for a ride in the back 40 with us. It ran good most of the day and the out of the blue quit and would barely run.

Daughter also reported the clutch was slipping.

So, I got a Ricks ignition coil and a complete clutch rebuild kit. Got those in tonight and it's running strong. Sam loves it! Now we need to get a few rides in to make sure it's good to go and we will hit the trails with it this summer. Sam has a part time job now and is dying to get the CT exhaust system for it and is saving up for it as we speak.

Those SunF Big Horn knock-offs frame Amazon seem to be a really good fit on the Blaster. Traction is good and being proper 20" size as all sport machines should have, they work well. Can't beat the price of $130 for the pair and one of the few 20" tires I could find for 8" rims.

Definitely going to do the hydraulic disc front brake conversion. Those cable actuated drums up front are terrible

I'll try to get some video of it next time we have it out.