PLEASE HELP! '87 LT 250R... died now wont start, MYSTERY
#11
PLEASE HELP! '87 LT 250R... died now wont start, MYSTERY
Jetting 101
This is not easy. You might want to consider taking it to a shop and having them do it, so you can get it close. Then you can just fine tune or adjust for weather/altitude.
This is not easy. You might want to consider taking it to a shop and having them do it, so you can get it close. Then you can just fine tune or adjust for weather/altitude.
#12
PLEASE HELP! '87 LT 250R... died now wont start, MYSTERY
It's really not that hard to jet for recreational purposes.
Essenstially start rich and lean out untill it runs clean and makes good power. When you're too rich you'll know it because it will run like crap. Then do a plug chop to double check.
For full throttle, basically go buy some main jets, start with you largest one (richest) and step down until the engine cleans up, step down one more and see if it feels like it makes more power, if it does do a plug chop, if it doesn't go back up one and do the plug chop.
For part throttle, set the needle clip on the 2nd to richest position (4 I think), it should stumble a little bit, then try the middle, if it's still rough go to 2nd clip position.
The pilot jet is easy idle screw 2 turns out and find the jet that it will start on easiest and have good throttle response. ~37.5 for mikuni carbs
As an example I started with a 330 main and ended up using either the 300 or 310 depending on weather and pre-mix oil.
Essenstially start rich and lean out untill it runs clean and makes good power. When you're too rich you'll know it because it will run like crap. Then do a plug chop to double check.
For full throttle, basically go buy some main jets, start with you largest one (richest) and step down until the engine cleans up, step down one more and see if it feels like it makes more power, if it does do a plug chop, if it doesn't go back up one and do the plug chop.
For part throttle, set the needle clip on the 2nd to richest position (4 I think), it should stumble a little bit, then try the middle, if it's still rough go to 2nd clip position.
The pilot jet is easy idle screw 2 turns out and find the jet that it will start on easiest and have good throttle response. ~37.5 for mikuni carbs
As an example I started with a 330 main and ended up using either the 300 or 310 depending on weather and pre-mix oil.
Thread
Thread Starter
Forum
Replies
Last Post
whitty
Polaris Ask an Expert! In fond memory of Old Polaris Tech.
67
02-24-2021 02:52 PM
02Chevrolet
1) Engine problems..
2
06-23-2015 12:12 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)