Dealing with AirFlow Challenged (ie Plugged) Radiators

Step-by-step tutorials on how to maintain and fix your GL1500
Post Reply
Posts: 27
Joined: Sat Oct 03, 2020 5:17 pm
Location: Kaslo, BC, Caada
Motorcycle: 1995 Aspencade SE

Dealing with AirFlow Challenged (ie Plugged) Radiators

Post by Albikes »

Admin(s) - This might make a good How-To Article.

Last week I purchased a 95 Aspencade 1500SE that has been sitting in a garage for at least the last seven years. As part of my detailed inspection I discovered that the Radiators were about 80 % blocked by what I take to be Bug Guts (The Bike spent most or all of its 61,000 Km on the roads in Alberta - Bug Country.) Photo following shows what I started with.

Never having seen a radiator this badly blocked off I was initially at a loss as to how to clean this mess up without wrecking the fins but after a bit of experimentation came up with the following.

1 - Get a good strong shop Vac. and gently run the hose over the rad in a left to right direction. You MUST go horizontally with the hose since going up and down runs the risk of closing off all of the fins. Repeat this step until there is no further improvement. It is OK to contact the rad with light pressure provided your hose end is plastic.

2 - Grab a can of WD40 and spray a liberal coat on about 1/4 of the rad surface let it sit for a few moments to soften up (rehydrate?) the bug guts. Now go over that area with the shop vac as described above. Repeat on the rest of the rad, and do it until you are no longer seeing any further improvement.

3 - Grab a strong Flashlight or shop light and shine it in the front of the radiator. Now look at the rad from behind through the hot air exits in the fairing. You will likely see mostly areas where the light is shining through, but also a few areas where there is no light. These areas will need further work as described below in the fourth and final step.

4 - Grab a 4", or so, Zip tie and use it to run through the blocked off areas. Be careful to run them through front to back only with minimal up or down movement so as not to close up the fins above or below. Photo below shows the end result. Not factory new but a damn site better than the 80% blocked radiators I started with. Optional - Give radiators a light spray of black paint to return them to a factory look.

Post Reply