high speed over heat

[willyboy]

i have a yamaha f250txr 2007 and above 2500 rpm it overheats but it takes 20 min @ 4500 rpm to get there i have replaced the water pump thermostats and pop it valve and the midsection with the new exhaust kit suggestions on other things to check?

[99yam40]

cooling passages plugging up

[Jason2tpa]

After cold start and allowing engine to warm, if 20min later running above 2500 rpms activates alarm I too agree with 99yam. Might have cooling passages blocked. Pull the heads and take a gander. Or you could first try flushing with one of the many products on the market that breakdown corrosion. Such as Salt-X. See if a few flushing sessions do the job.

[TownsendsFJR1300]

When you did the WP, did you install the entire kit and did you look for ANY DAMAGE /warping to the WP HOUSING? Any damage to that housing WILL cause issues.

How much salt build up did you see with the thermostat and poppit valve out?

Just for S&G's, (before yanking heads), you may want to remove the thermostat housing and run the motor with the cover off (briefly) just to see if your getting sufficient water to the top of the block.

If plenty of water, you may want to pull some head anodes and look there as well:

2006 and Later F250TXR Yamaha Outboard CYLINDER CRANKCASE 2 Diagram and Parts


Agreed with both responses too...

[fairdeal]

it could be useful to know the water pressure at the engine when it is running at 4500 -

Boscoe recently suggested a very easy way to connect a gauge - simply connect it to the flush hose

[seabiscuit]

I have just found this forum and have a similar problem with my F225 (2008 with 860 hours). Does your engine run hot enough to set of the high heat alarm, or, do you simply see the temp rising above the normal running temperature based on the yamaha heat gauge? I am interested to see what you find out. It might help me with my situation. Let us know.
Also, if anyone reading this has hands on experience with any of the cooling system flushing/cleaning products, I'd like hear which ones they think work the best.
I'll follow your thread to see what happens before starting a new one with basically the same questions and probably the same suggestions.
thanks

[TownsendsFJR1300]

I have just found this forum and have a similar problem with my F225 (2008 with 860 hours). Does your engine run hot enough to set of the high heat alarm, or, do you simply see the temp rising above the normal running temperature based on the yamaha heat gauge? I am interested to see what you find out. It might help me with my situation. Let us know.
Also, if anyone reading this has hands on experience with any of the cooling system flushing/cleaning products, I'd like hear which ones they think work the best.
I'll follow your thread to see what happens before starting a new one with basically the same questions and probably the same suggestions.
thanks

Some good results with pic's:

http://www.yamahaoutboardparts.com/f...g-th19434.html

http://www.yamahaoutboardparts.com/f...m-th23666.html

http://www.yamahaoutboardparts.com/f...h27868-p2.html

[seabiscuit]

Exactly the kind of reply I was looking for. Those are pretty good testimonials.
I will give this a try and see if it works for me before moving on to the next step.
Thank you. I will post the results, although, it will be a few weeks before I will be able to do the flush.

[pstephens46]

Exactly the kind of reply I was looking for. Those are pretty good testimonials.
I will give this a try and see if it works for me before moving on to the next step.
Thank you. I will post the results, although, it will be a few weeks before I will be able to do the flush.

Seabiscuit has a high speed overheat?

Wonder when Yamaha started using the new and improved exhaust parts in the F225?

[fairdeal]

Seabiscuit has a high speed overheat?

Wonder when Yamaha started using the new and improved exhaust parts in the F225?

LOL - take a deep breath, pstephens, - this isn't THT!

mid-section exhaust corrosion manifests as overheat alarm at idle -

at high rpms there's enough pump output to overcome the leakage

[boscoe99]

LOL - take a deep breath, pstephens, - this isn't THT!

mid-section exhaust corrosion manifests as overheat alarm at idle -

at high rpms there's enough pump output to overcome the leakage

Thank God.

[pstephens46]

LOL - take a deep breath, pstephens, - this isn't THT!

mid-section exhaust corrosion manifests as overheat alarm at idle -

at high rpms there's enough pump output to overcome the leakage

I was simply confirming the high speed condition......

Since Seabiscuit piggybacked on someone else's thread, without full disclosure, you never know......

Like the guy a few days ago mentioning his vst drains without releasing the pressure. Or some such nonsense. He asked if he should worry about it. He didn't mention the engine had an issue at some sort of rpm in his initial post.

Btw, when did Yam start using decent exhaust pieces in that motor?

Maybe Solo will chime in with his opening line "Gots me three F225s" With a video of his wake......

[fairdeal]

Btw, when did Yam start using decent exhaust pieces in that motor?

I don't think I ever bothered to look;
if Boscoe has ever mentioned specifics here or elsewhere I either forgot or failed to notice.

From a quick look now;
the exhaust plate - what I think of as "ceiling of the muffler" - was on my 2005 TXRD 69J-45181-00-5B

that part number carries through until April 2009, when it changed to
69J-45181-10-9S
which is the part included in the "kit"

[seabiscuit]

I thought I would give an update after trying the Rydelyme procedure. I followed the procedure as outlined and it worked just as described. I have not had an overheat situation occur since using it.
Sorry if I "piggybacked" on someone else's thread. You just never know.... Ha!
Thanks to those with helpful information.

[TownsendsFJR1300]

I thought I would give an update after trying the Rydelyme procedure. I followed the procedure as outlined and it worked just as described. I have not had an overheat situation occur since using it.
Sorry if I "piggybacked" on someone else's thread. You just never know.... Ha!
Thanks to those with helpful information.

Thanks for the update and the successful results.