Bog, Backfire and Burning too much oil Help!

nickleuci

New member
Joined
Nov 16, 2006
Messages
65
Location
weare nh
98 700sx stock, 7500 miles, carbs clean

OK I went out 2 times this year and on both occasions it was pretty cold outside, -14F the first time and -10F the second. On both occasion when I started the sled it bogged and backfired for 2-4 minutes when I hit the gas. I could gas through the bogging and backfiring and get it moving. This went away after the sled warmed up.

The sled was also smoking quite a bit while idling, this also seemed to go away after warming it up.

On the last ride I did 120 miles and my low oil level light came on. It was full to start.

My questions are
So I'm clearly buring way too much oil. Would this cause the bogging and backfiring during a cold start?

Did the 98's have an issue with the oil pumps crapping out? Where shoud I start looking for the cause of the oil problem.

Cable connections are all ok, at first I thought the oil pump cable just pulled apart at the connection point near the carbs (which could have happened during the carb cleaning process).
 
bogging

nickleuci said:
98 700sx stock, 7500 miles, carbs clean

OK I went out 2 times this year and on both occasions it was pretty cold outside, -14F the first time and -10F the second. On both occasion when I started the sled it bogged and backfired for 2-4 minutes when I hit the gas. I could gas through the bogging and backfiring and get it moving. This went away after the sled warmed up.

The sled was also smoking quite a bit while idling, this also seemed to go away after warming it up.

On the last ride I did 120 miles and my low oil level light came on. It was full to start.

My questions are
So I'm clearly buring way too much oil. Would this cause the bogging and backfiring during a cold start?

Did the 98's have an issue with the oil pumps crapping out? Where shoud I start looking for the cause of the oil problem.

Cable connections are all ok, at first I thought the oil pump cable just pulled apart at the connection point near the carbs (which could have happened during the carb cleaning process).


Did you check the oil pump cable gap? What kind of oil are you using?
 
yamalube 2S

I did not check the gap, how do I do that? Can I get to the oil pump by just pulling the carbs/airbox? Looks like it's below the carbs.
 
OK I did some searches and it sounds like I need to start by making sure my adjustments for idle and free play on the throttle are correct. Plus I'll need to get at my oil pump and make sure it's properly adjusted.

It looks like the oil pump is under the carbs on the 98 700sx. Is that correct? Am I looking at the right parts.

Also would the excess oil cause the bogging and misfire/backfire? Or is that another issue? Is it possible the free play on the throttle was not adjusted properly causing the tors to come, and if so only when the sled is cold. That doesn't make sense to me.
 
The excess oil will definitely cause problems. Thats probably the main cause of your bogging. Mine was doing the exact same thing, fixed the problem and carbs are happy again.

As far as whats causing the heavy usage... *shrug* Hope yours is as easy to find as mine was (cable misrouted)
 
oil

The oil pump gap needs to be checked. The oil cable from the throttle lever is coupled together around the air box area. There is a rubber boot over the connection that needs to be rolled or pulled back. Once the boot is out of the way, pull the two cable sheath ends apart and measure the gap between the two outer cable sheathes. There is an adjuster at the gap....but make sure you have the throttle free play set correctly first.
 


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