Jump to content

Engine trouble on an SR125


i like my SR
This post is 6636 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

Hi, im a relative newb, ive been riding for over a year now, and have recently got an SR125 SE. Ive had to change the engine for a newer one, as it decided to drop one of its valves in to the barel.

The Newer engine is off of a 97 bike, and it is so far running well (ish).

There is one problem though, when I come off the throtle in any gear above 3rd, the power will go compleatly, and the engine dies (as in no fuel being combusted), or when I give her a little throtle, she will sometimes become very laboured in reving, and will almost stall, or die (in neutral). It only seems to hapen when the engine is warm/hot.

I think it could be the carb, or an air leak in to the carb gaskits, but im not sure, and I cant really afford to send it in to the garage.

Can anybody help me out?

Cheers.

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.
  • Moderator

I think it could be the carb, or an air leak in to the carb gaskits, but im not sure, and I cant really afford to send it in to the garage.

Can anybody help me out?

Cheers.

Try pointing an UnLit propane torch @ the joints where gaskets are questionable while it's running.....

If you have an air leak, the revs will pick up a bit.....thus sucking the propane fumes through any leaks that are there.

Easy & cost efficient technique in finding those dodgy gasket related probs ;)

BTW...... :welcome: to the forum mate :)

Link to comment
Share on other sites

  • Moderator

Did the carb come with the engine? or have you swapped em ? there is a possibility of jetting changes,

try Scotts idea, if that does not work it could be a blocked pilot jet. but you would not get a good tickover if the pilot is blocked.

merv

Link to comment
Share on other sites

The tick over is a bit slow and can become very laboured, and yes, it was the carb that was on the original engine.

but how could the pilot jet become blocked by just changing the engine over?

Link to comment
Share on other sites

  • Moderator

The tick over is a bit slow and can become very laboured, and yes, it was the carb that was on the original engine.

but how could the pilot jet become blocked by just changing the engine over?

Has that carb sat for any length of time?

Cuz, with those symptoms.....it definitely sounds like a clogged pilot.....which is actually pretty easy to remedy....especially on a Single. ;)

Link to comment
Share on other sites

  • Moderator

By original engine you mean the one that was fitted to the bike that dropped the valve?

Well it could be some muck in the float bowl got disturbed during the changeover, Can you check if the jetting is the same in both carbs I:E the one fitted and the carb that should be with the engine now fitted

merv

Link to comment
Share on other sites

by original, i mean the 24 year old engine that came with the bike (same Vin numbers).

and, the current carb may have been dissloged when we took appart the engine. (the gas thing diddnt work btw, thanx tho). we had a bit of trouble trying to get the fuel back in to the cylinder and combusting. (about 20 min trying to get the thing to spark up)

thanx.

kim

Link to comment
Share on other sites

  • Who's Online (See full list)

    • There are no registered users currently online
  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...