Main jet advice for Laser 50 after MRP exhaust upgrade

[pauld581]

Hi- I am a little confused about the recommended main jet size for a laser 50 (2004) that has a mrp exhaust. I have seen jets as high as 80 or higher some places and as low as 65 to replace the stock 60. I do understand that it varies from machine to machine, but I don't want to buy a bunch of jets to try.

Also, after the exhaust upgrade I am getting good speed- up to 42 or higher, but there seems to be a bit of a lag getting there. It's almost like a turbo lag. I figure this is because I need to change the weights, and the rec I've seen here is for 5 gram sliders...is this the consensus?

Thanks, and please feel free to add any other advice you've got!

[harry]

which mrp exhaust do you have?

elevation and climate are main factors along with
type of mod...
closer to sea level you would have a bigger jet  vs high
elevation would be a smaller jet.

pipes generally use 4-6gr  weights, but you should change
both main & clutch springs

oilyhans

[pauld581]

oilyhans-
I have the MRP MP-02060. I am in Fort Collins, Colorado, so elevation is ~5000 feet or so. Can you recommend a jet and perhaps talk more about clutch springs...how hard is this for a competent but untrained person to do?

Also, I wanted to buy my MRP from you, but you have been out of stock on that for a while. I have a month or so to do my upgrades and then I need to gear up for work (teaching). My scooter is a main transport for me, so I really wanted to get a reliable 45 MPH or better when I am done. I should also add that I have had this machine since new and it is now at 5400 miles. I do maintenance myself.

Thanks so much for all your advice and help on this board.

Paul

[harry]

the pipe you have does it fit your scooter?  i've sold that pipe
but have had reports that the center stand has to be removed at least
on the KeyWest because it doesn't go all the way up..
FYI ; anything in stock at MRP i can have it dropped shipped to you.

at 5,000' you should only need to go to a 65 to 75 at the max
but don't take that as gospel you will have to do some plug chops
to confirm your scooter is not running lean. that does mean buying
2 or 3 jets. the total amount will be $14 extra you have to spend on jets
thats so much cheaper than having to replace the piston and cylinder!
jets are here;
http://whidbeyislandmoped.com/cart/index.php?main_page=index&cPath=10

as for the springs they are a bit harder to replace and you will
need a impact  tool to remove the nut &AND take safety precautions!!!!!
so when you take the driven pulley assembly apart
you need to keep it from flying apart and the clutch springing
up into your face, as the main spring is under tension when
it is in place.
i made a "press" that holds it under compression
while you remove the nut and then you can release the
pressure slowly until its gone. it also makes it easy to
assemble  when reversing the process.

oilyhans

[pauld581]

To put that pipe on my Laser I had to remove the center stand. I believe that I actually could get it back on but I do not use it that much anyway so I probably won't bother.  I also needed 2x 3" long 10mm bolts to mount the pipe since you are unable to fit the pipe with the bracket flush to the existing mount. Other than these two things it fit fine.

I hear you on the jets; no problem spending $20 or whatever to save the piston and cylinder. When I swapped the pipe I put in a new plug and I will be watching it closely over the next few days. The most I will be riding it in the next week or so is probably 5 miles or so total. In the meantime I would like to order 65-70-75 jets from you, or whatever closest you have that are appropriate.

On your site I am seeing: 60 to 80 in 2.5 increments but no 65s listed, no 70s listed, and 67.5 as being sold out...can you advise?

As for the springs I might think about paying someone to do that at some point, or tackling it myself later. For now I would like to get Dr. Pulley sliding weights. You have the six gram but are sold out on 5 gram. Should I wait for the 5 gram or just get the  6 gram? IOW is the one gram going to make that much of a difference?

I can get an impact wrench for doing the weights; there are plenty of videos and stuff that show how to do that, so I am not worried about it.

I probably will want more airflow after the re-jet...correct? I was thinking about drilling holes in the air  cleaner basket, one at a time, and seeing how I go after each 7/8 hole. Is this reasonable?


Thanks again, look forward to giving you some business,
Paul

[harry]

i just restocked the jets but haven't changed the website
to reflect the new inventory.. i believe i have all in
stock from 60 or 62.5.

one word of caution ;do not drill or use a open filter
keeping your scooter running & tuned right is such a
pita   you have to re tune every time the seasons or weather changes

you should really do the springs and the sliders at the same time.

the 'press' is easy to make;  gather up
 some 3/4" plywood and buy some 3/16" all thread
4 nuts, 2 fender washers and 2 wingnuts.
 cut 2 pcs ply to 8"x 12"
 cut a 2" hole in one in the center  this will be the 'top'
cut 2 all thread  10" long
find center of un drilled ply(bottom) ,measure your  driven assembly
(it can be removed from the scooter safely) and plot the
circle in the center of un drilled ply
 drill 2 holes for the all thread  outside of the circle by about 1"
attach both all thread to the bottom with the 4 nuts (you may want to drill
out a bit of the back of the bottom ply for the nuts to be recessed)

place the driven pulley assembly on bottom of press add top ply and
put washers on the all thread and tighten the wingnuts.
remove nut on pulley and carefully back off the wingnuts.. for
reassembly you just line up the flat spots on the
clutch and shaft and crank down  the wingnuts then put on the nut.

now you can replace the main spring and the clutch springs safely.

 oilyhans

[pauld581]

I'm wondering if it wouldn't be more cost-effective (and maybe easier, for me) to replace the clutch entirely? My bike does have 5400 miles on it, after all, and I see you have several replacements in the $50-60 range...what do you think? Also, which clutch would I get? I do not think I want or need a racing clutch.

If I can get the jets, the sliders, and the clutch/clutch parts for $100 or so, that would be fine. If you could let me know a good time to call, I'll give you a call on Tuesday and order up.

Thanks again,
Paul

[harry]

you still have to disassemble  the driven pulley  to remove the clutch.
however, the stock clutch is fine its the clutch springs that need replacing.

i updated the jet inventory all #62.5-90 in 2.5 increments and 90 up to 110 in 5
in stock

oilyhans

[pauld581]

Okay, I guess I will have to give it a go. I understand your press but I am wary of attempting this alone- but what the hey.

If you can link me to the springs I need I will order  a 65, 70 ,and 75 jet, plus the springs, plus whatever sliders you recommend. I am thinking that if I go ahead with six gram they would be these:
http://whidbeyislandmoped.com/cart/index.php?main_page=product_info&cPath=11&products_id=38

If you think I should wait for the five gram I will do so.

Paul

[pauld581]

After some research I ordered the 1500 RPM main and clutch springs. I have watched several videos of people changing clutch springs using various methods/hacks. Not sure which way I will go with it but I am more confident now than I was before seeing the videos.

As promised, I also ordered 6 gram sliders, and one each 65,70, and 75 jet.

I will probably need help so I will post questions in a new thread, and no matter what I will report on my findings and ultimate outcome. For right now I actually haven't ridden the scooter much since I put on the exhaust, so the spark plug is still essentially new.  We have been having a lot of late afternoon rain here in northern Colorado, which at this time of year is when I am most apt to ride it, so I just haven't had the opportunity.