Malossi BBK for People 50 2T

[chaz35]

Wow pace, that's amazing that it still runs.  You could probably pull the cylinder/ piston, clean it up a little, and probably be OK!  Did you know scooterpartsco has rings for the Malossi kit for approx $15?

So, the cable didn't break or pull the ball off the end?, ball just popped out of the oil pump lever?  You were running combo premix and oil pump, right?

How did you change out the bushing in the carb?  That's the main reason I am staying with what the carb came with.  I don't know how to change out the parts, I am afraid will tear it up before even get to use it lols.

[paceneedsstides]

its running fine right now on premix lost a coupe mph but probably due to running less gas need to upjet. no the cable snapped at the ball or pulled put theres no fraying or wear just a complete fail and before I was running only oil pump no premix at all after break in. As for the AU Bushing I took bowl, and atomizer out took out slide and put a skinny flathead into atomizer hole and tapped the old one out. Maneuvered the c shaped AU bushing into place with needle nose pliers with opening facing intake not air filter.  Found a small socket that just fit over C put it on a 1/4 extension and tapped it down till I was hitting sides of venturi then screwed AU atomizer up into bushing till it was seated and done.

[chaz35]

pace, thanks for how to on installing AU nozzle.  I pushed on mine some, but didn't budge.  If mine doesn't run right, will be the next thing to change on my carb.

In the chaos after you lost the oil pump, did you get CHT reading, or max reading?, would be very interesting info.  Cheers

[paceneedsstides]

I wasn't hot when it happened and afterwards don't think I've gone over 377 but I'm having to rejet and tune again for premix. And you got to do more than push on the bushing lol its tight.

[chaz35]

pace, thanks for info on CHT.  I guess that sounds right, didn't get hot before seizing up.  Won't run without oil, even if nice and cool lols.

I got carb parts in from treatland, everything looks good, especially the choke I really like.

I needed a little longer cable outside the housing for the bent tube, approx 2 1/4" longer.  I was able to remove approx 2 1/4" of the housing without cutting off the end of the cable.  I previously watched vid about moding throttle cables and had the idea from one of them.  I put the housing in a vise with 2 1/4" of the cable housing protruding, then I pulled on the housing to stretch it.  After I had it stretched enough, I was able to spin the cable out of the stretched housing and cut off the excess housing.  Worked pretty well, next time will do a better job of it.  Still haven't had to solder an end to a cable.

I installed 98 main jet, new choke, and everything else as supplied by Malossi (if came from Malossi, must be good right?).  I am putting scooter back together to test.  I rerouted the throttle cable at the top going to the twist grip so it won't bind like it was before, have to route cable up close to the steering shaft like it comes OEM.

One issue I have with the Dellorto carb is installing/ disassembling cable to/ from the barrel.  Must be a trick to this, the little plastic piece that holds the needle in place is a pain.  Maybe, with a little more cable to work with will be easier.  Also, getting the end of the cable to go through the bent tube is fun, not.

If it doesn't run cooler now, will be very disappointed.  Cheers

[paceneedsstides]

sounds like youre on the right track and no theres no trick to that plastic pice on top of needle and slide it's just a pita. On a positive note ParaIndiana is alive and well if not active over here he's actually joined my CLubs Facebook group so Imma drain him on all the info I can when it comes to the Like 50 2T his is over 60 with the upgear kit.

[blufx]

and hard to imagine but could be dangerous.  OK to use air to blow out bearings, just don't free spin them to the moon.  Cheers

When I was a teen, I had just changed a front wheel bearing on my '63 Chevy. I had the old bearing brushed out with solvent, I then stuck my finger through it and started blowing with compressed air. Like you, I found myself spinning as fast as I could and it sounding like a turbine. About that time my older brother stepped over and said, " I heard of a guy doing that, and the bearing locked down. The bearing had so much momentum, it twisted his finger off". I have no idea if it's true, but it's not hard to imagine. I've never done it again. Not on my finger anyway. Still got to play sometimes.

[chaz35]

good story blufx, I liked it!

[chaz35]

The saga continues, more trouble.  I got it all back together and took for a test run.  Was running great, but definitely still getting hot.  Carb had 98 main jet. needle clip 2 grooves from the top.  I was cruising approx 80km a little faster than my safe speed with the modified OEM Keihin PB16 and it was running nice, but building temp faster, actually faster than I realized.  I stuck the engine, CHT max was 446F.  I was pretty sad, main concern was pushing it back home, what a pain.  I let it cool down to approx 300F and tried to start it, started 1st kick, so I drove it home.

At 1st I didn't know what to do, but eventually realized maybe just needed a larger main jet, so I installed the largest one I have a 102 and went for another test ride.  Rode the same route to test again, still getting too hot, and fouled the plug, I guess from some metal from the stick.  Anyway, appears no harm done, still has good compression, starts easy, runs great, except gets too hot.

I have metric mini drill set and the 102 main jet measured approx 1mm.  The next size mini drill is 1.2mm, so I drilled out the 80 main jet the carb came with to 1.2mm, installed it, put in new plug, and went for another test run.  Same, still will not cruise without overheating, but I could tell the main jet was actually too rich now.  WOT temp holds steady, but can tell too rich to run really well, if back off throttle to maybe 1/2 throttle, it runs leaner/ better, but still overheats.  So, next I will raise the needle jet, I am going to try the bottom groove to raise needle all the way.

I think getting pretty close, but this engine may always be prone to overheating.  Unless I have something assembled wrong, like cylinder head, fan shroud?  Maybe there is something missing from scooter that is keeping the air from flowing across the cylinder properly, I don't know?  The only other thing I know to do is test the squish, but don't know what's it's supposed to be.  I can add another cylinder base gasket to raise the cylinder relative to the piston and decrease squish/ compression a little, that should help detune it a little, let it run cooler?  I need to pull the cylinder to look at the piston/ cylinder anyway.

This thing actually runs like a monster for short runs.  I noticed I have cars following me around to see what I am going to do next.  I even had nice looking babe roll down her window and wave at red light, I guess she couldn't tell I am old guy lols?

[Chris0381]

Let me ask.

Is your oil pump cam all the way open or at max 1mm over full open at full throttle.

[chaz35]

Chris, thanks for reply.  Oil pump connected like normal, set to open the maximum amount.  I was careful to set so the stop just bottoms out at WOT and doesn't put undue tension on the cable.

Maybe needs more oil, but don't think more oil would help it run cooler, just protect it better when it does get too hot?

[chaz35]

OK, next test with needle raised, then probably order some larger main jets.  With needle raised, maybe 102 is OK?  Wish I knew equivalent Dellorto main jet for 1.2mm mini drill?  Guess will order 104, 106, 108, 110?  Then will have 96, 98, 100, 102, 104, 106, 108, 110, have to buy lots of jets to test, but only use one.

I do like 19mm carb, very nice to loosen clamp, turn carb so can remove bowl, and change out main jet.  For another $30 or so, can get racing bowl with screw hole in the bottom, so don't have to mess with 4 screws.  I can see stripping out the  little bowl screws sooner or later, then the carb body is trash.  With the OEM carb, was removing the seat to get to carb to remove it, was easy to do, but took awhile, was a pain.  Cheers

[paceneedsstides]

yes this is carb is great for jetting. wow I have never gotten up to 446 I've never even gotten to 400 but I do have the same problem as you running lean and hot through 3/4 throttle but I run cool and rich to the point of fouling and backfiring at WOT for anything more than two minutes on a 94 main jet and I'm running an open filter now too.

[paceneedsstides]

get the jet set I got like 20 or them lol a couple sizes I have multiple ones of. it sounds like we both may need a different needle one slightly slimmer than W7 I say at scoottunning.ca they have a PHBG needle set which has like 5 sizes for $20 or something like that I may pick that up and give it a try.

[paceneedsstides]

oh and our Malossi BBKs don't have squish so no need to worry bout that