Problem on quick throttle openings/Low RPM

[M.V.]

Hi everyone, this is my first post here (sorry it's to ask for help), but I have found this site very helpful & I will be sticking around. I'm typing up my intro post as we speak

I'm at the end of my tether on this one, I can't seem to find the problem...

It starts & idles fine, (from cold) & is fine with smooth throttle roll on, but when you whack the throttle open, it bogs down. If I back the throttle off & then roll on smooth it works fine. Happens at all revs...

The other part is, when it is warmed up, the idle will jump every now & then, like you've given the throttle a small blip, & will stall under 3K rpm when taking off. Small throttle opening don't really do anything, to get going I need to rev to 3/4K & slip the clutch a lot.

It all started when I took the carbs off a couple of weeks ago to give them a clean, (found my throttle cable was frayed, so I ordered a new one) made sure to keep all the parts in their respective carbs etc, my Emulsion tubes & needles seem fine, & as far as I can tell, all of my vacuum lines are intact. Pulled the carbs down again last night, thought I had fixed it, because it was idling beautifully, but when I took it for a spin, no such luck

Before this it was working fine, so I know it's something I have done, really frustrating.

I think that's it, hope someone's got some ideas!

[Killerwhale]

Hi everyone, this is my first post here (sorry it's to ask for help), but I have found this site very helpful & I will be sticking around. I'm typing up my intro post as we speak

I'm at the end of my tether on this one, I can't seem to find the problem...

It starts & idles fine, (from cold) & is fine with smooth throttle roll on, but when you whack the throttle open, it bogs down. If I back the throttle off & then roll on smooth it works fine. Happens at all revs...

The other part is, when it is warmed up, the idle will jump every now & then, like you've given the throttle a small blip, & will stall under 3K rpm when taking off. Small throttle opening don't really do anything, to get going I need to rev to 3/4K & slip the clutch a lot.

It all started when I took the carbs off a couple of weeks ago to give them a clean, (found my throttle cable was frayed, so I ordered a new one) made sure to keep all the parts in their respective carbs etc, my Emulsion tubes & needles seem fine, & as far as I can tell, all of my vacuum lines are intact. Pulled the carbs down again last night, thought I had fixed it, because it was idling beautifully, but when I took it for a spin, no such luck

Before this it was working fine, so I know it's something I have done, really frustrating.

I think that's it, hope someone's got some ideas!

Usually if one blips the throttle and the revs drops and fights to get to idle when closing it´s very fat, if it revs high and goes down to idle after a while it´s lean. ...but...a bog is usually lean.
I would check and re-check that fuelscrews etc are at correct turns out....but actually also check that there are not any junk stuck somewhere in the carbs now. Perhaps even take it to someone who can clean them in a sonic cleaner.
I take it you have checked and re-checked all hoses....there are a few...

[M.V.]

Yeah, checked & rechecked the vacuum hoses!

So it may not be getting enough fuel, problem might be further back from the carbs. I'll check the fuel tap & pump I guess.

Thanks for the input.

[trixynut]

I had a similar 'woolly' response on mine once. Just happened overnight.

Ended up getting the carbs balanced by a mechanic and all was fine and has been since. No new bits were needed.

Maybe an idea..?

[M.V.]

Yeah, good idea! I hadn't suspected balance because I didn't alter it, but any way, Ill give it a crack.

I have the carbs stripped down at the moment, while I'm there there I might as well do the coolant, spark plugs & oil!

I'll give yamaha a ring tomorrow & find out how much emulsion tubes are, might as well do those too if it doesn't break the bank...

[Killerwhale]

Yeah, good idea! I hadn't suspected balance because I didn't alter it, but any way, Ill give it a crack.

I have the carbs stripped down at the moment, while I'm there there I might as well do the coolant, spark plugs & oil!

I'll give yamaha a ring tomorrow & find out how much emulsion tubes are, might as well do those too if it doesn't break the bank...

http://cgi.ebay.co.uk/yamaha-tdm850-trx ... 7C294%3A50

[G Beale]

Yamaha tubes are 20 quid each, same price as Factory Pro ones.

[Killerwhale]

Yamaha tubes are 20 quid each, same price as Factory Pro ones.

But are they nickel plated???

[M.V.]

Ah, it seems I haven't set my profile up, how much in Australian Quid?

Edit: I was doing some work to the bike last night, & it ran fine until it got warm, then the revs actually dropped (I thought they were jumping up), but it was idling around 1200, then it got warm, the idle droppped to 1000 & would jump back to normal every now & then.

Any one have any ideas?

[Killerwhale]

Ah, it seems I haven't set my profile up, how much in Australian Quid?

Edit: I was doing some work to the bike last night, & it ran fine until it got warm, then the revs actually dropped (I thought they were jumping up), but it was idling around 1200, then it got warm, the idle droppped to 1000 & would jump back to normal every now & then.

Any one have any ideas?

Running fat, when it´s warm it becomes even more obvious....or something simple as the choke is stuck on a bit....

So your downunder, then someone would know in the aussie thread where to get the factory pro´s

[M.V.]

I didn't think the emulsion tubes were too bad, but I guess I better replace them while I'm at it.

Yamaha wanted $73 odd dollars each, & $91 for the needles

Have ordered the factory pro emulsion tubes for $35ea & the jet kit with needles for $150 odd.

Bad news is they will take three weeks to come

Should I turn the slow jet screw in half a turn to lean it out a bit in the mean time?

Or drop the needle down one clip?

[bazzee]

Hey MV,

where did you order the emulsion tubes from?

bazzee

[M.V.]

Ordered from Mick Hone Motorcycles, I'll chuck up their number tomorrow, or google should turn it up quicksmart.

[bazzee]

Thanks, I have checked the Factory Pro website which says that Mick Hone is a distributor, but the Mick Hone website has become a little sparse on detail and they seem to only want to sell stuff via their ebay shop.

I might try Matt Mladin's shop http://www.bikegearwarehouse.com.au/ seeing as he also got a mention on the Factory Pro site and they're a bit closer to Sydney than Mick Hone. There is no mention of Factory Pro on the BikeGearWareHouse website so I guess I just have to ring them up and ask.

Cheers,

bazzee

[M.V.]

I just called Mick Hone after seeing the name on the factory pro site, didn't bother with the website. I tried the BGW website, but it's a bitch to naivgate, couldn't owrk out if they sold the stuff or not! Let me know if they do, might be a lot cheaper