1988 R100RT fuel line replacement

[9842]

Hi
When I pulled the tank I noticed small cracks in the fuel lines. So I want to replace them. I'm concerened about running the horizontal hose under the air box. Where can I find out what I have to do to get the fuel line through from one side to the other. I recently did it on my slash five and it was a process and I had to slightly remove the airbox a little to make room for the fuel line. The RT air box is different so any tips are appreciated.
Thanks
Brian

 

[stevenrankin]

Bit of a job

Yeah the air cleaner on the newer bikes can be a bit of a problem. You will have to remove the horns to the carbs. Remove the top cover and the filter. Under the plumbing for the air injection system is at least one vertical bolt into the transmission #8, at the bottom of the box. If I recall correctly and with my teflon memory there is a nut in front #10 and a bolt #11.
Take them out and you should be able to lift the box enough to push a new line trough St.

 

[franko]

Can you take the end of the new hose to the end of the old hose. Then push the new hose more than pull the old hose. The old hose will guide the new hose. By pushing more than pulling, it will help keep the hoses taped together and help it around the edges.
A barbed connector could be used to join the hoses also.
If this fails, you can always take it apart and do it like you had planned.
I wasn't able to do this when I changed mine because I pulled the hose out before thinking the job through.

 

[Omega Man]

Can you take the end of the new hose to the end of the old hose. Then push the new hose more than pull the old hose. The old hose will guide the new hose. By pushing more than pulling, it will help keep the hoses taped together and help it around the edges.
A barbed connector could be used to join the hoses also.
If this fails, you can always take it apart and do it like you had planned.
I wasn't able to do this when I changed mine because I pulled the hose out before thinking the job through.

If you try this technique, I can recommend that you spray the outside of the hoses with silicone spray to aid in the resistance reduction as the hoses are pulled through.

OM

 

[9842]

Replace fuel line

Can you take the end of the new hose to the end of the old hose. Then push the new hose more than pull the old hose. The old hose will guide the new hose. By pushing more than pulling, it will help keep the hoses taped together and help it around the edges.
A barbed connector could be used to join the hoses also.
If this fails, you can always take it apart and do it like you had planned.
I wasn't able to do this when I changed mine because I pulled the hose out before thinking the job through.

Hi Guys
You confirmed my thoughts. Can you believe three different nuts/bolts, and at different positions. I'm hoping I can loosen bolts and move or slide air box a little and slide the hose through. I'm really hoping I can simply pull or push the new line through without getting into the air box. I tried sliding/pulling fuel line through on my /5 recently and no go. I assume the same for the RT. So it looks like a simple fuel line replacement job is now a "since ya job". Since ya doing this you might as well do that. Looks like I'm spending a day pulling and cleaning as I go.
Thanks for the info.
Brian

 

[stevenrankin]

Pulling

I have never had any luck just pulling the line trough. Then again, I don't use the OM braided crap anymore but fuel injector line of proper diameter. It is a bit stiffer walled than the braided crap.

The good thing about fuel injector line is once I installed the last lines, I haven't had to replace and I don't remember how many years/miles ago that was. St.

 

[r1200rst]

One trick is after you pull the old hose out is to take a long phillips screwdriver of the right size and feed it thru and slip the new hose over it and pull it back thru.

 

[9842]

Fuel line replaced

One trick is after you pull the old hose out is to take a long phillips screwdriver of the right size and feed it thru and slip the new hose over it and pull it back thru.

Thanks for all the tips. None of them worked haha. Took me around 3 hours. I cleaned as I went, had some music playing, nice and warm in my new shop with plenty of light. I first tried pulling and pushing the old line and nothing, it was jambed. Removed side covers, left fuel line and Carb tube, top of air box and air filter and the left horn inside air box. At that point I had enough room to remove two big transmission #6 Allen bolts and one vertical hex bolt. This air box is really bolted down and I'm in there with a tiny Allen wrench. I have Allen sockets but kinda tight so took my time with the Allen wrench. Removed two of the three bolts and loosened the third so I could wiggle and lift the box just enough and slip the hose through. I left the last bolt so I would not struggle lining it up on reassembly. So I'm in the home stretch right, nope. The top of the tranny has external ribs and as I'm sliding the hose its hitting each rib. Determined not to completely remove the box I wiggled, turned and rotated the line and made it almost all the way. I did use a screwdriver to center the line and pulled it the rest of the way. Oh the rest of the lines were easy, and reassembly went well. All clean and wiped down and I feel good about another job well done. Thanks for your input and tips, I don't have a manual for this bike and couldn't really find anything oneline for fuel line replacement. Seems straight forward but I find BMW has their way of doing things and I always feel relieved when I finish a job I'm not familiar with.
Thanks again
Brian

 

[Omega Man]

Always good to hear how things worked out.

OM

 

[stevenrankin]

Sounds like me

Brian, putting on music when working sounds like me, LOL. Yeah, BMW design sometimes in my shop leads to eruptions of volcanic language. But as you say it is great when a job is done successfully.

At least we can work on our bikes ourselves. St.

 

[AntonLargiader]

I wish I'd seen this earlier but it sounds like some positive bonding time happened so it's all good. . The current fuel line BMW sells goes through easily. Take it to the grinding wheel and taper the end (just 1/4" or so) so it looks like a hole punch. Feed it through and align it with a screwdriver or something when it gets to the other opening. Twist a bit and it goes through, every time. Then snip off the tapered bit.

 

[9842]

Fuel line- 3rd time is a charm

Hi Gang
It's Brian again, time to change out fuel lines on my third bike in the last two years. I first replaced lines on my blue 73 toaster, then last year on my 88RT. This time of year I like to drain out some gas and refill with race fuel. This year I have 98 octaine unleaded gas to top to refill bikes with fresh gas. Today I'm draining my float bowls on three airheads and I notice a wet line, Damm! The Rt was a pain to change out with the air box bolted down and external ribs on tranny acting like hurdles to get the line over. So this Green 73 toaster should be easier. Fewer steps and one simple bolt holding the air box. I like the look of the braided line, but I understand that rubber fuel injection line is better. Do any of you know of or recommend a new braided line that looks original and will stand up to the new gas?
Thanks
Brian

 

[20774]

Wow...strange! I can't remember the last time I had any fuel line leaks on any of my bikes. I think the last braided fuel line I bought was from Vech at Bench Mark Works who sold out to Max BMW. I'd consider three sources - a BMW dealer, Bing in Kansas, or check to see what local VW bugs use on their cars.

 

[9842]

Leaky fuel line on 4th bike in 2 years

Hi
Yup, had to swap out fuel lines on my last bike today. As mentioned above I was draining old gas out of the float bowls for the winter and noticed leaky fuel lines on the 4th out of my 4 bikes in the last two years. I guess the gas at the pump is eating away at the braided line.

I used rubber looking, non braided, fuel injected 1/4 inch ID line from the auto parts store. No more braided line for me, even though I think it looks better I'm not using it anymore. And the job was just as difficult as the first three times. Difference was I was ready this time. Put on BMW, Bob Marley & the Whalers on the old stereo. I have a really nice workshop so it was a pleasure to do the job, just not an easy task. Had to remove the airbox to slide the horizontal line through. Someday I want to watch someone pull/push a line through with out removing the box. I had no luck on all 4 replacements.

So bikes are all on tenders with racefuel in the tanks and bowls dry.
I will exercise the bikes on dry sunny days over the winter.

Thanks again for all the tips and techniques. The job is finished and I feel good that the bike is ready to ride.

Brian

 

[lkchris]

Just a tip not related to the original question...

In post # 2, note part #15

That's the airbox water drain. Note that it is on the clean side of the filter. With motor running, the flex in the rubber combined with engine vacuum, closes it.

Yours ought to be maintained in like new condition to avoid dirt entry into your airbox and then carburetors.