Bought my first 2-stroke, but she’s a mess

ERM9683

Member
Mar 22, 2024
14
9
44
41
Hey everyone - thanks for having me. Wanted a blaster since I was a kid in the early 90’s, now I have one. Gonna restore it over time aesthetically, but when it comes to the motor - lots of new things. But I cannot get this thing to start (has spark, brand new cdi and stator)…think it’s the carb. Looks like an aftermarket Amazon deal. Gonna pull the jets to see the sizes, but I also want to take care of this thing.

Is there a good, already jetted carb brand new available?? This thing already had the tors delete done. I AM in the process of getting the oil injection block-off plates, as the oil tank itself has been removed. Would that have anything to do with it?? I apologize for my extreme ignorance…this is my first two stroke. Many thanks in advance!!

Eric
 
Welcome aboard.

Yes, there is a good carb available as an upgrade for a stock to moderately modified Blaster. What you want to do is sh*t-can the Amazon carb and find a genuine Keihin PWK28 and an assortment of genuine Keihin jets. I've heard of some who managed to get a Chinese carb to work, and others who didn't. It's not worth the gamble to me, save yourself the hassle and pony up for the genuine article. For the pilot jet I would get #38 through about #45, and for the main I would get #138 through about #145. The sizes run in increments of two to three. Example: if you currently have a #142 main, the next size richer will be #145.

Be careful shopping, most of the regular reputable retailers of these carbs have been out of stock lately and eBay might be you only option in finding one. A lot of people peddling chinesium knock-offs and listing them as genuine Keihin. Searching for OEM carb for 85cc-100cc or so Japanese and KTM dirt bikes should help bird-dog some up for you. I got burned on a knock-off recently. They are getting very good at copying the real Keihins, shameless and a fair bit trickier to spot looking at pics. I sent it back.

Once you get a PWK, it will fit into the reedvalve intake boot no problem. But the air box boot will be much more stubborn. I managed to get mine stuffed into the air box boot by removing the boot from the air box, not fun but it allowed me to work with it easier and massage it over the carb intake bell.

As to hard starting, also check your reedvalve. Check for broken or chipped reed petals. This can also cause hard starting/no starting. Genuine V-Force 4 reedvalve is a good choice, that's what I got for my daughters Blaster. Be careful of knock-offs with the reedvalve too. I ended up getting mine from Rocky Mountain ATV after getting sent a knock-offs from eBay that was claimed to be genuine. Sent it back. It was priced a bit cheaper than RMATV, but not so cheap as to throw a red flag. It can't be overstated how unscrupulous these peddlers of knock-off parts are nowadays. Buy from reputable retailers whenever possible to avoid this nonsense.

Also for the no-start, check for a sheared/missing flywheel key. This indexes the flywheel for proper ignition timing.

If you have any questions, feel free to ask. I can help you with finding a carb and jets too if needed.
 
THANK YOU for the info. I almost bought a Vito’s 28mm carb, but found a guy near me who sells blaster parts that had one OEM carb left…PSYCHED. So now, I have to do the trouble shooting. Any advice on jet kits would be appreciated!
 
  • Like
Reactions: RIDE-RED350r
Whichever option you choose as far as a carb, I would get a range of jets on hand for the pilot and main. If sticking with the OEM carb you'll need OEM Mikuni jets. I'm not as familiar with how Mikuni jet sizes run compared to Keihin, but I would get about three steps leaner and richer than stock for both pilot and main. There is really no set "jet kit" that will be the right combination for every machine in every circumstance. You'll want to jet your Blaster to whatever it calls for based on how it performs. There are some good pinned threads on jetting guidelines and how to go about it.

As I said before, Chinese carbs are hit and miss. Some report success with them, others not so much. I know Vito's sells a Chinese made copy of the Keihin PWKs and that's cool because they disclose what you are getting. I've just never felt it was worth rolling the dice and spent a little more on genuine Keihin carbs from reputable sellers and retailers. I've never had a bad experience with a Keihin PWK, from the little baby 28mm on my daughters Blaster, to the 38mm Airstryker on one of my 250R, to the 41.2mm PWK bored by Eddie Sanders on my big bore 250r. Great carbs and always respond predictable to jetting changes.
 
Whichever option you choose as far as a carb, I would get a range of jets on hand for the pilot and main. If sticking with the OEM carb you'll need OEM Mikuni jets. I'm not as familiar with how Mikuni jet sizes run compared to Keihin, but I would get about three steps leaner and richer than stock for both pilot and main. There is really no set "jet kit" that will be the right combination for every machine in every circumstance. You'll want to jet your Blaster to whatever it calls for based on how it performs. There are some good pinned threads on jetting guidelines and how to go about it.

As I said before, Chinese carbs are hit and miss. Some report success with them, others not so much. I know Vito's sells a Chinese made copy of the Keihin PWKs and that's cool because they disclose what you are getting. I've just never felt it was worth rolling the dice and spent a little more on genuine Keihin carbs from reputable sellers and retailers. I've never had a bad experience with a Keihin PWK, from the little baby 28mm on my daughters Blaster, to the 38mm Airstryker on one of my 250R, to the 41.2mm PWK bored by Eddie Sanders on my big bore 250r. Great carbs and always respond predictable to jetting changes.
THANK YOU again….it is beyond appreciated. I’m trying to keep this blaster in the family so that the kids can ride it & learn how to take care of it. I got the Vito’s drill / tap kit (couldn’t find info on the drill bit size or tap size - I have both taps and drill bits, but didn’t want to go nuts and mess the carb up). I’ve gotten jets from jets r us before, and will do it again for this. Thanks for the suggestion, and will report back when I get everything!
 
  • Like
Reactions: RIDE-RED350r
THANK YOU again….it is beyond appreciated. I’m trying to keep this blaster in the family so that the kids can ride it & learn how to take care of it. I got the Vito’s drill / tap kit (couldn’t find info on the drill bit size or tap size - I have both taps and drill bits, but didn’t want to go nuts and mess the carb up). I’ve gotten jets from jets r us before, and will do it again for this. Thanks for the suggestion, and will report back when I get everything!
*Got jets for my 1980 Yamaha XS1100
 
  • Like
Reactions: RIDE-RED350r
Glad to help a fellow 2-stroker out 🍻
So I got my oem carb (for SURE needs to be cleaned), my wiring harness, chain guide, and block-off plate. I’m waiting on the idle screw drill kit from Vito’s. I could not for THE LIFE OF ME find the size of the drill bit, because I have a tap / die kit and could’ve done that myself. No big deal - just want to resurrect this thing!
 
  • Like
Reactions: RIDE-RED350r
Yep, best to get what is 100% certain to be the correct tap. Otherwise if it's tapped incorrectly you will be MacGyvering some other random screw in there. My bet is that it's metric and very fine thread pitch. Finer than what is typically readily available at your local hardware
 
Yep, best to get what is 100% certain to be the correct tap. Otherwise if it's tapped incorrectly you will be MacGyvering some other random screw in there. My bet is that it's metric and very fine thread pitch. Finer than what is typically readily available at your local hardware
I now have everything I need. Quick question: what oil does the transmission take?? About to drain it and block the oil injection when I get a chance. Got some plugs for a plug-chop as well.
 
  • Like
Reactions: RIDE-RED350r
Usually 10w-40 is what was recommended for two stroke transmission oils on these machines. Nowadays you need to look for a 10w-40 that is stated to be wet clutch compatible. I run Valvoline ATV 10w-40 oil that is wet clutch itch compatible in my 250Rs and Blaster.
 
Hey, it’s been crazy lately being I have a newborn, but slowly trudging away on this thing. So, I’m seeing more and more insane sh*t on this engine…kid put BOLTS IN THE HEAD instead of studs, got stripped Phillips head screws out of the clutch cover (actually had to grind the last flange nut he used so I could get the cover off to do the oil injection delete)…I wanted to learn how to work on the 2-smokes, and now I’m in over my head. Take a look at the cylinder…should I say “hell with it”, and just buy a good used engine, hone it, or get a cylinder for this thing?? I wanted to eventually get a Vito’s 240 kit for it, but wanted more experience before I go down that route. The bottom end is good…
 

Attachments

  • IMG_7075.jpeg
    IMG_7075.jpeg
    1.9 MB · Views: 20
  • IMG_7076.jpeg
    IMG_7076.jpeg
    1.5 MB · Views: 21
  • IMG_7077.jpeg
    IMG_7077.jpeg
    1.5 MB · Views: 20
I would bore that cylinder assuming it's not at max bore already. Good chance the piston is scored and needs to be replaced. Need to ascertain the reason why and address it.
 
I bought an oem rebuilt carb from kebr_3835 on eBay he sells oem rebuilt carbs with and without tors delete if it’s fake eBay money back Garuntee . Also has the tors delete been done properly as far as the harness goes? I like putting south texas banshee harness for cleaner setup.
 
  • Like
Reactions: RIDE-RED350r
I bought an oem rebuilt carb from kebr_3835 on eBay he sells oem rebuilt carbs with and without tors delete if it’s fake eBay money back Garuntee . Also has the tors delete been done properly as far as the harness goes? I like putting south texas banshee harness for cleaner setup.
I have an oem carb with TORS delete that I already tapped, and it’s set up for an aftermarket exhaust. The stock exhaust looks like sh*t (pinholes in 4 spots), and I’m starting to lean towards this being a parts blaster. The kid I got it from is the son of a VERY DEAR old friend that I haven’t seen in two decades , and the kid was trying to buy his first car. I couldn’t bring myself to back out…he was literally about to go buy his FIRST CAR. Great people, but the kid didn’t have a clue what to do to this thing, and I can’t fault him for trying. I have a new wiring harness, exhaust gasket(s), top end gaskets…LOTS of essentials. The rear axle / carrier looks pretty sh*tty as well….
 
  • Like
Reactions: RIDE-RED350r
I have an oem carb with TORS delete that I already tapped, and it’s set up for an aftermarket exhaust. The stock exhaust looks like sh*t (pinholes in 4 spots), and I’m starting to lean towards this being a parts blaster. The kid I got it from is the son of a VERY DEAR old friend that I haven’t seen in two decades , and the kid was trying to buy his first car. I couldn’t bring myself to back out…he was literally about to go buy his FIRST CAR. Great people, but the kid didn’t have a clue what to do to this thing, and I can’t fault him for trying. I have a new wiring harness, exhaust gasket(s), top end gaskets…LOTS of essentials. The rear axle / carrier looks pretty sh*tty as well….
Sound like you should be okay now than . Pass a leak down test and the blaster should be ripping in no time