Yamaha TRX850 Enthusiasts Forum

Hi All

Hope someone can help... Having just recommissioned my Trix after a year off of the road I am finding that she won't start on cold mornings? I put new plugs, filters, oil, battery, etc in as part of getting her back on the road and when the days are warmish she starts fine. But if the temperature is below about 6 degrees she just turns over endlessly without kicking into life? If I use a blow torch to warm up the front of the engine a bit she then starts up. Any suggestions on what to do are greatly appreciated.

Mark

Have you checked valve clearance? What's the mileage?

The mileage is just over 17000 and the valve clearences were set about 2000 miles ago so I was not thinking in that direction?

I hope you mean 6 degrees celcius

If so, yes, I would be checking the valve clearances first, sounds like they may have closed up or been done wrong.

You haven't yet suggested using the choke mechanism yet...

alextrx850 wrote:You haven't yet suggested using the choke mechanism yet...

Someone on here had a buggered choke mechanism IIRC

The choke needs to be used in the morning to get her started and it seems to work as it should (as far as I can say without stripping the mechanism).

Try anything that will make it run weak - carb rubbers vacuum pipes etc.

Also check choke is comming on

If it has been laid up, was petrol drained as the carbs may be gummed up with old fuel, try stripping and blowing out carbs and jets empty old fuel out of tank and fill with fresh fuel

Just a thought - don't use any throttle when using the choke, or else the choke won't operate.

If it's warm enough on May 7th you could take a run out to the Leadburn Inn - there should be a fair gathering of bikes on the first Thursday of the month...............

it should need the choke to start when its cold. If it doesn't it is too rich. For some reason people consider it a fault when a bike wont start cold unless its on the choke. This is incorrect. This about it, why would you set up a bike to run well at 6 degrees when 5 minutes after you start it it is running at 70 degrees. You tune a bike with the engine heated up, and you have a choke to compensate for cold starts.

Thanks for the support folks

It started fine tonight (Nice weather, 16 degree heat) and didn't miss a beat on a blast around the local area. I am going to try and find time over the weekend to pull the carbs off and clean out, inspect pipes, etc. I think I will also compression test the cylinders to see if there is any indication of a valve problem.

I would have loved a blast out to the leadburn inn dandywarhol, but sadly work commitments are going to take me elsewhere on the 7th . But possibly catch up the following month there?

Cheers again folks

Mark

Did it require choke at 16 deg. tonight? Mine did - just about half, then shut off within about 5 seconds

After struggling to start tonight (cold) I pulled out the plugs... even though the engine must have turned over for about 1 minute and a half the plugs were still dry? Does that suggest gummed carb problems? I was going go do a compression test but just discovered my compression tester does not go down to a size Small enough to fit in the plug hole!

Does suggest your not getting any fuel, if you didn't drain the fuel, the carbs might be full of crap - modern fuel is full of shit additives and petrol goes off! If you are getting a good spark as timing is fixed it really leaves fuel. Does it pop, bang and try to fire?

Nope. Nothing like that. It either starts (Temp above 6 degree) or just continually turns over until the battery runs flat. I spoke to a trustworthy biker mechanic today who thinks it is more likely to be a vacuum pipe or old perished rubber link between the carbs and cylinders. His point was that if it was gumming up of the carbs the bike would run rough even after staring... which it doesn't! Once it is going it runs great!!

I have pulled the carbs off tonight and the carb to head rubbers are pretty badly perished ( as you would expect from a 19 year old machine) and have ordered up a replacement set, I will service the carbs and reinstate with the new rubbers, then let you all know how things are going.

Thanks again

Mark