[sbcmistake]

so my uncle has 2 tw200's.

1 of which wont start unless starting fluid is used then dies imeddiately as though it is no getting fuel



the other will start(last year this bike would only run with full choke even after warmed up) and run until we give it gas then it dies and will not start again.



they are the same year bikes between 01 and 03. one has 431 miles and the other has 430 miles.



they get used for hunting every year and once during the year for trail riding. after each use the fuel bowls get drained. and the batteries disconected.



he also has to put new batteries in them every year!





anything helps at this point. we have one week until our annual hunting trip and would like to get them goimg for it.

 

[qwerty]

Both sound like symptoms of ethanol in the gasoline. First thing I would do is give the carbs a good cleaning.

 

[jbfla]

...the other will start(last year this bike would only run with full choke even after warmed up) and run until we give it gas then it dies and will not start again.

Carbs are gunked up, common with bikes that have been sitting unused for long periods of time. Most likely the float bowl needle/seat is clogged up or stuck closed, so no fuel goes through the carb except through the choke circuit.



Carbs need to be cleaned, chemically with Seafoam, or mechanically by disassembling the carb.



When putting the TW's away for the season, it's a good idea to add Stabil or Seafoam to the gas, and/or drain the carb. Also, remove the battery and put it on a Battery Tender.



jb

 

[sbcmistake]

yeah getting ready to undergo cleaning of the carbs. the gas i get is 10% ethanol as it is the most common in idaho to the tune of 90%+ of gas stations around her only carry gasahol. is there a way to adjust the air fuel mixture without changing the jets?

 

[jbfla]

... is there a way to adjust the air fuel mixture without changing the jets?

The only adjustment to the fuel mixture on the outside of the carb is the pilot screw, also called the idle mixture screw, or the fuel screw.



It is located on the bottom of the carb, usually behind a plug, unless someone has already removed it.



This screw affects mainly from idle to about 1/4 throttle. They are set a bit lean from the factory.



From your description, I would suggest giving the carb a good cleaning before trying any mixture adjustments.



*** Don't get carb cleaner on any rubber parts: rubber gaskets, o rings, or the slide diaphram.



jb

 

[sbcmistake]

thanks for all the help. i was able to get both of them running better than they did when bought new. there is one little bug i haven't been able to work out of one though. it has a slight hestitation in it that it has always had when taken from idle to half-full throtle. and when the bike were at our local yamaha shop when we got them. the techs changed the jets to 132.5's. any suggestions?

 

[qwerty]

thanks for all the help. i was able to get both of them running better than they did when bought new. there is one little bug i haven't been able to work out of one though. it has a slight hestitation in it that it has always had when taken from idle to half-full throtle. and when the bike were at our local yamaha shop when we got them. the techs changed the jets to 132.5's. any suggestions?

132.5 jets are not from Yamaha. As far as I know Yamaha jets only go up to 132. If they are not OEM Yamaha jets that 132.5 number may or may not correspond to the Yamaha number system. I pulled a 130 out of one TW and the hole was visibly smaller than the stock 125.



The hesitation before acceleration sounds like your needle is too low or the pilot screw is too far in, too far out, or the float level is too low or high.

 

[sbcmistake]

i pulled them back apart and checked the jet numbers again and the tops are marked 132.the one that looks like it has 132.5 is on the bike that snake river serviced(our local yamaha dealer). i called them and talked to the tech that keeps customer records and he confirmed that it is a stock jet for a kodiak quad with a mikuni carb and that when the bikes were new they did in fact change the jets to adjust for altitude in cascade id. cause my uncle requested to have them adjusted for altitude

 

[qwerty]

Isn't the altitude at Cascade something like 4500 feet? If so, I'm pretty sure the stock 125 jet would be closer to correct than a 132. Probably the 128 would be ideal, at least in my experience.

 

[sbcmistake]

yeah its at 4700-4800 feet in town and on the mountain were we go huntin its varies from close to 5000 at the base and upwards of 7800 feet at the summit but if they will run better with smaller jets in them i'm all for changin em. before i try to buy the bikes from my uncle at 4000 for th pair

 

[qwerty]

The higher the altitude the richer TWs run, all else beiung equal. At 5000 to 7000+ feet I'd try the 125 first, then go from there.

 

[sbcmistake]

thanks for the tips qwerty these bikes are running alot better. they just seem to not have the power they should. like they had 400 miles ago. i'll try the smaller jets in them and see if that resolves the issue.