Reviving A -99 Tdm 850

[anda3243]

You are and do! I've been and read the entire thread again.  :istupid:

 

but then

 

I'd suggest two approaches.

1. First, first and firstly, source an airbox that hasn't been modified. You may find out that the airbox inlet tract is more useful if it is left in place. It's a bit of an unknown factor at the moment. I've seen airboxes that have been modded on the dyno - with only one or two 10mm holes drilled through the tract into the filter centre. Then any surplus holes have been taped over with duct tape. Your airbox by comparison is wide open. I suspect it is a major factor in this story.
   
2. Dropping/extending the needles is a no brainer. The 850 carbs sliders are being tested by the suck of the 900 pots. Your goal is to get the sliders working and the fuel/air mix correct through the entire rev range of the engine. Just change one aspect of the carbs at a time to get a feel for the effect. Dropping the needles doesn't cost anything. You know what you are doing here better than I do so I'll shut up now. You're most likely correct regards the jetting.
   
3. Excellent project!
   

 

Good point, The airbox mod can be causing problems. I will try to find an used airbox lid with the snorkel intact. I have already ordered 155 and 160 size main jets, but I will try changing the airbox lid first.

 

Regarding the sliders. Last time I opened the carbs, I noticed that the sliders were worn. They have been pulled downwards by the suction and become worn. I did not check how much they had worn down, but it could maybe be causing problems.

 

Thank you!